MULTIPLEX COMMUNICATION – MULTIPLEX COMMUNICATION SYSTEM

MP–1

MULTIPLEX COMMUNICATION
SYSTEM
PRECAUTION
NOTICE:
• When disconnecting the cable from the negative (-)
battery terminal, initialize the following system after
the cable is reconnected.
• When the warning light is illuminated or the battery
has been disconnected, pressing the power switch
may not start the system on the first try. If so, press
the power switch again.
System Name

See Procedure

Power Window Control System

IN-32

MP

MP–2

MULTIPLEX COMMUNICATION – MULTIPLEX COMMUNICATION SYSTEM

PARTS LOCATION
BEAN BUS

CERTIFICATION ECU*
COMBINATION METER

TIRE PRESSURE
MONITOR ECU

GATEWAY ECU

POWER SOURCE
CONTROL ECU

TRANSPONDER KEY ECU

TRANSMISSION CONTROL ECU

DLC3
A/C ECU

DRIVER SIDE JUNCTION BLOCK
- MAIN BODY ECU

MP
*: w/ Smart Key

B126158E02

MULTIPLEX COMMUNICATION – MULTIPLEX COMMUNICATION SYSTEM

MP–3

AVC-LAN BUS

MULTI-DISPLAY

GATEWAY ECU

RADIO AND PLAYER

DLC3

NAVIGATION ECU*

*: w/ Navigation System
B126159E02

MP

MP–4

MULTIPLEX COMMUNICATION – MULTIPLEX COMMUNICATION SYSTEM

SYSTEM DIAGRAM
*1: w/ Navigation

: AVC-LAN
: BEAN

*2: w/ JBL Audio

: CAN

*3: w/ VSC

Gateway ECU

Multi-display

*4: w/ Smart Key
Navigation
ECU*1

Radio and Player
Audio
Amplifier*2

ECM

HV ECU

Yaw Rate and
Deceleration Sensor*3

Power Source
Control ECU

Combination
Meter

Tire Pressure
Monitor ECU

Certification
ECU*4

Junction Connector 2
Battery ECU

Transmission
Control ECU
ABS ECU
Transponder
Key ECU
EPS ECU
Junction Connector 1

MP

Steering Angle
Sensor*3
DLC3

Driver Side
Junction Block

A/C ECU

B133175E04

MULTIPLEX COMMUNICATION – MULTIPLEX COMMUNICATION SYSTEM

MP–5

SYSTEM DESCRIPTION
1.

MPX (MULTIPLEX COMMUNICATION NETWORK)
The MPX connects the ECUs of this vehicle and uses an
ON-OFF signal (binary 0 and 1) to communicate with
each ECU. The ECU operates the actuator based on the
other ECU information. For example, the ECM (PCM)
allows the engine to start based on the transponder key
ECU information. The MPX consists of 3 networks: AVCLAN (Audio Visual Communication Local Area Network),
BEAN (Body Electronics Area Network) and CAN
(Controller Area Network). The gateway ECU is
connected to and coordinates communication between
the 3 networks.

MPX Cross-reference
Network

Protocol

Wire Harness

AVC-LAN

TOYOTA original

Twisted twin wire

Maximum 17,800 bps*

0 to 32 byte

BEAN

TOYOTA original

Single line

Maximum 10,000 bps*

1 to 11 byte

CAN

ISO 15765-4

Twisted twin wire

500,000 bps* (Maximum 1
Mbps)

1 to 8 byte

2.

Speed

Data length

HINT:
*: "bps" indicates bits per second.
AVC-LAN (AUDIO VISUAL COMMUNICATION LOCAL
AREA NETWORK)
The audio/visual system uses the AVC-LAN. The master
ECU is connected to gateway ECU and sends the signal
to the other ECUs. The wire harness is a twisted twin
wire covered with the insulation. One wire is used for the
positive voltage and the other wire is used for the
negative voltage.

ECU

Gateway ECU

ECU

Master ECU
(Multi-display)

ECU

MP

B133172E01

MP–6

MULTIPLEX COMMUNICATION – MULTIPLEX COMMUNICATION SYSTEM

3.

Gateway ECU

BEAN (BODY ELECTRONICS AREA NETWORK)
The body electrical system uses the BEAN. The ECUs
are connected to the gateway ECU like a daisy chain.
This maintains the communication if the wire harness
has an open circuit. The wire harness is a signal core
line covered with insulation.

ECU
ECU

ECU

ECU
ECU

ECU

B133173E01

4.

MP

CAN (COMMUNICATION AREA NETWORK)
The powertrain and chassis system use the CAN. The
CAN circuit has 2 master ECUs. One master ECU is
connected to the other master ECU by the main wire.
The gateway ECU and other ECUs are connected to the
main wire by the branch wire through the junction
connector(s). The wire harness is a twisted twin wire
covered with insulation. One wire (CANL) is 1.5 to 2.5
volts and the other wire (CANH) is 2.5 to 3.5 volts.

MP–7

MULTIPLEX COMMUNICATION – MULTIPLEX COMMUNICATION SYSTEM

Gateway ECU
Terminator
(120 ǡ)

Master ECU (ECM)

ECU

ECU

Junction Connector

ECU

ECU

Junction Connector

Terminator
(120 ǡ)

Master ECU
(Battery ECU)

B133174E02

MP

MP–8

MULTIPLEX COMMUNICATION – MULTIPLEX COMMUNICATION SYSTEM

HOW TO PROCEED WITH
TROUBLESHOOTING
HINT:
• Use this procedure to troubleshoot the multiplex
communication system.
• *: Use the intelligent tester.

1

VEHICLE BROUGHT TO WORKSHOP

NEXT

2

CHECK BATTERY VOLTAGE
Standard voltage:
11 V or higher
If the voltage is below 11 V, recharge or replace the battery
before proceeding.

NEXT

3

CHECK DTC OF CAN COMMUNICATION SYSTEM
(a) Using the intelligent tester, check if the CAN is
functioning normally.
Result:
Result

Proceed to

CAN DTC is not output

A

CAN DTC is output

B

B

Go to CAN COMMUNICATION SYSTEM

A

4

CHECK FOR DTC*
(a) Check for DTCs and note any codes that are output (see
page MP-16).
(b) Delete the DTC.
(c) Recheck for DTCs. Try to prompt the DTC by simulating
the original activity that the DTC suggests.
Result:

MP

Result

Proceed to

DTC does not reoccur

A

DTC reoccurs

B

B
A

Go to step 6

MULTIPLEX COMMUNICATION – MULTIPLEX COMMUNICATION SYSTEM

5

MP–9

OVERALL ANALYSIS AND TROUBLESHOOTING
(a) Terminals of ECU (see page MP-9).

NEXT

6

ADJUST, REPAIR OR REPLACE

NEXT

7

CONFIRMATION TEST

NEXT
END

MP

MP–10

MULTIPLEX COMMUNICATION – MULTIPLEX COMMUNICATION SYSTEM

TERMINALS OF ECU
1.

CHECK GATEWAY ECU

G1

B126164E01

(a) Disconnect the G1 connector.
(b) Measure the voltage and resistance of the wire
harness side connector.
Symbols (Terminal No.)

Wiring Color

Terminal Description

Condition

Specified Condition

BATT (G1-10) - Body
ground

Y - Body ground

+B (BATT) power supply

Always

10 to 14 V

IG (G1-1) - Body ground

B - Body ground

Ignition power supply

Power switch ON (IG)

10 to 14 V

ACC (G1-2) - Body ground

P - Body ground

ACC power supply

Power switch ON (ACC)

10 to 14 V

SIL (G1-7) - Body ground

W - Body ground

Bus "+" line

During transmission

Pulse generation

MPD2 (G1-12) - Body
ground

GR - Body ground

BEAN line

Always

10 kΩ or higher

MPD1 (G1-3) - Body
ground

GR - Body ground

BEAN line

Always

10 kΩ or higher

GTX+ (G1-6) - Body
ground

B - Body ground

AVC-LAN line

Always

10 kΩ or higher

GTX- (G1-21) - Body
ground

W - Body ground

AVC-LAN line

Always

10 kΩ or higher

GND (G1-24) - Body
ground

W-B - Body ground

Ground

Always

Below 1 Ω

2.

If the result is not as specified, there may be a
malfunction on the wire harness side.
CHECK A/C ECU

A8

MP
B133133E01

(a) Disconnect the A8 connector.
(b) Measure the voltage and resistance of the wire
harness side connector.
Symbols (Terminal No.)

Wiring Color

Terminal Description

Condition

Specified Condition

+B (A8-6) - Body ground

Y - Body ground

+B power supply

Always

10 to 14 V

MPX+ (A8-3) - Body
ground

B - Body ground

BEAN line

Always

10 kΩ or higher

MULTIPLEX COMMUNICATION – MULTIPLEX COMMUNICATION SYSTEM

MP–11

Symbols (Terminal No.)

Wiring Color

Terminal Description

Condition

Specified Condition

MPX2+ (A8-11) - Body
ground

GR - Body ground

BEAN line

Always

10 kΩ or higher

GND (A8-1) - Body ground

W-B - Body ground

Ground

Always

Below 1 Ω

If the result is not as specified, there may be a
malfunction on the wire harness side.

MP

MP–12

MULTIPLEX COMMUNICATION – MULTIPLEX COMMUNICATION SYSTEM

3.

Vehicle Rear Side

CHECK DRIVER SIDE JUNCTION BLOCK (MAIN
BODY ECU)

Vehicle Front Side

1G
B5
1A
1E

Main Body ECU

1A

1E

1G

B5

MP

B126166E02

(a) Disconnect the B5 ECU connector.
(b) Disconnect the 1A, 1E and 1G junction block
connectors.

MULTIPLEX COMMUNICATION – MULTIPLEX COMMUNICATION SYSTEM

MP–13

(c) Measure the voltage and resistance of the wire
harness side connectors.
Symbols (Terminal No.)

Wiring Color

Terminal Description

Condition

Specified Condition

ECUB (1A-30) - Body
ground

R - Body ground

+B (ECUB) power supply

Always

10 to 14 V

MPX1 (1G-9) - Body
ground

GR - Body ground

BEAN line

Always

10 kΩ or higher

MPX2 (B5-15) - Body
ground

B - Body ground

BEAN line

Always

10 kΩ or higher

GND (1E-17) - Body
ground

W-B - Body ground

Ground

Always

Below 1 Ω

4.

If the result is not as specified, there may be a
malfunction on the wire harness side.
CHECK TRANSPONDER KEY ECU

T5

9 8 7 6
5 4 3 2 1
24 23 22 21 20 19 18 17 16 15 14 13 12 11 10

B126056E01

(a) Disconnect the T5 ECU connector.
(b) Measure the voltage and resistance of the wire
harness side connector.
Symbols (Terminal No.)

Wiring Color

Terminal Description

Condition

Specified Condition

IG (T5-4) - Body ground

O - Body ground

+B (IG) power supply

Always

10 to 14 V

MPX1 (T5-17) - Body
ground

B - Body ground

BEAN line

Always

10 kΩ or higher

MPX2 (T5-16) - Body
ground

GR - Body ground

BEAN line

Always

10 kΩ or higher

GND (T5-22) - Body
ground

W-B - Body ground

Ground

Always

Below 1 Ω

If the result is not as specified, there may be a
malfunction on the wire harness side.

MP

MP–14

MULTIPLEX COMMUNICATION – MULTIPLEX COMMUNICATION SYSTEM

5.

CHECK TRANSMISSION CONTROL ECU

T4

B126167E01

(a) Disconnect the T4 ECU connector.
(b) Measure the voltage and resistance of the wire
harness side connector.
Symbols (Terminal No.)

Wiring Color

Terminal Description

Condition

Specified Condition

+B (T4-1) - Body ground

L - Body ground

MPX1 (T4-19) - Body
ground

GR - Body ground

+B power supply

Always

10 to 14 V

BEAN line

Always

10 kΩ or higher

MPX2 (T4-18) - Body
ground

B - Body ground

BEAN line

Always

10 kΩ or higher

E1 (T4-15) - Body ground

W-B - Body ground

Ground

Always

Below 1 Ω

6.

If the result is not as specified, there may be a
malfunction on the wire harness side.
CHECK CERTIFICATION ECU (WITH SMART KEY)

S11

17 16 15 14 13 12 11 10
9 8 7 6 5 4 3 2 1
40 39 38 37 36 35 34 33 32 31 30 29 28 27 26 25 24 23 22 21 20 19 18

B126057E01

(a) Disconnect the S11 ECU connector.
(b) Measure the voltage and resistance of the wire
harness side connector.

MP

Symbols (Terminal No.)

Wiring Color

Terminal Description

Condition

Specified Condition

+B1 (S11-1) - Body
ground

R - Body ground

+B power supply

Always

10 to 14 V

MPX1 (S11-31) - Body
ground

GR - Body ground

BEAN line

Always

10 kΩ or higher

MPX2 (S11-32) - Body
ground

B - Body ground

BEAN line

Always

10 kΩ or higher

E (S11-17) - Body ground

W-B - Body ground

Ground

Always

Below 1 Ω

If the result is not as specified, there may be a
malfunction on the wire harness side.

MULTIPLEX COMMUNICATION – MULTIPLEX COMMUNICATION SYSTEM

7.

MP–15

CHECK COMBINATION METER

C10

B126168E01

(a) Disconnect the C10 meter connector.
(b) Measure the voltage and resistance of the wire
harness side connector.
Symbols (Terminal No.)

Wiring Color

Terminal Description

Condition

Specified Condition

+B (C10-21) - Body
ground

Y - Body ground

+B power supply

Always

10 to 14 V

MPX+ (C10-24) - Body
ground

B - Body ground

BEAN line

Always

10 kΩ or higher

MPX- (C10-25) - Body
ground

GR - Body ground

BEAN line

Always

10 kΩ or higher

SE (C10-14) - Body
ground

BR - Body ground

Ground

Always

Below 1 Ω

8.

If the result is not as specified, there may be a
malfunction on the wire harness side.
CHECK POWER SOURCE CONTROL ECU

P6
17 16 15 14 13 12 11 10
9 8 7 6 5 4 3 2 1
40 39 38 37 36 35 34 33 32 31 30 29 28 27 26 25 24 23 22 21 20 19 18

B126057E02

(a) Disconnect the P6 ECU connector.
(b) Measure the voltage and resistance of the wire
harness side connector.
Symbols (Terminal No.)

Wiring Color

Terminal Description

Condition

Specified Condition

AM1 (P6-33) - Body
ground

R - Body ground

+B (AM1) power supply

Always

10 to 14 V

MPX1 (P6-7) - Body
ground

GR - Body ground

BEAN line

Always

10 kΩ or higher

MPX2 (P6-24) - Body
ground

B - Body ground

BEAN line

Always

10 kΩ or higher

GND2 (P6-6) - Body
ground

W-B - Body ground

Ground

Always

Below 1 Ω

If the result is not as specified, there may be a
malfunction on the wire harness side.

MP

MP–16

MULTIPLEX COMMUNICATION – MULTIPLEX COMMUNICATION SYSTEM

9.

CHECK TIRE PRESSURE MONITOR ECU
T11

C107243E03

(a) Disconnect the T11 ECU connector.
(b) Measure the resistance of the wire harness side
connector.
Symbols (Terminal No.)

Wiring Color

Terminal Description

Condition

Specified Condition

IG (T11-1) - Body ground

B - Body ground

Power supply

Always

10 to 14 V

MPX1 (T11-6) - Body
ground

W - Body ground

BEAN line

Always

10 kΩ or higher

MPX2 (T11-12) - Body
ground

B - Body ground

BEAN line

Always

10 kΩ or higher

GND (T11-7) - Body
ground

W-B - Body ground

Ground

Always

Below 1 Ω

If the result is not as specified, there may be a
malfunction on the wire harness side.

MP

MULTIPLEX COMMUNICATION – MULTIPLEX COMMUNICATION SYSTEM

MP–17

DIAGNOSIS SYSTEM
1.

DESCRIPTION
The gateway ECU sets a diagnosis trouble code (DTC) if
a malfunction occurs in the multiplex communication
network (MPX). The intelligent tester allows the DTC to
be displayed when the tester is connected to the DLC3.

2.

DLC3
The vehicle's ECU uses the ISO 15765-4 communication
protocol. The terminal arrangement of the DLC3
complies with ISO 15031-3 and matches the ISO 157654 format.

CG SG CANH SIL

CANL

BAT
H100769E22

Symbols (Terminal No.)

Terminal Description

Condition

Specified condition

SIL (7) - SG (5)

Bus "+" line

During transmission

Pulse generation

CG (4) - Body ground

Chassis ground

Always

Below 1 Ω

SG (5) - Body ground

Signal ground

Always

Below 1 Ω

BAT (16) - Body ground

Battery positive

Always

11 to 14 V

CANH (6) - CANL (14)

HIGH-level CAN bus line

Power switch OFF

54 to 69 Ω

CANH (6) - Body ground

HIGH-level CAN bus line

Power switch OFF

1 MΩ or higher

CANH (6) - CG (4)

HIGH-level CAN bus line

Power switch OFF

1 kΩ or higher

CANL (14) - Body ground

LOW-level CAN bus line

Power switch OFF

1 MΩ or higher

CANL (14) - CG (4)

LOW-level CAN bus line

Power switch OFF

1 kΩ or higher

If the result is not as specified, the DLC3 may have a
malfunction. Repair or replace the harness and
connector.
HINT:
Connect the cable of the intelligent tester (with CAN
VIM) to the DLC3, turn the power switch ON (IG) and
attempt to use the tester. If the screen displays the
message UNABLE TO CONNECT TO VEHICLE, there
is a problem either with the vehicle or the tester.
If communication is normal when the intelligent tester is
connected to another vehicle, inspect the DLC3 on the
original vehicle.
If communication is still not possible when the tester is
connected to another vehicle, the problem is probably in
the tester itself. Consult the Service Department listed in
the tester's instruction manual.

Intelligent Tester

DLC3
CAN VIM
B126098E01

MP

MP–18

MULTIPLEX COMMUNICATION – MULTIPLEX COMMUNICATION SYSTEM

DTC CHECK / CLEAR

Intelligent Tester

1.

2.

DLC3
CAN VIM
B126098E01

MP

CHECK DTC
(a) Connect the intelligent tester (with CAN VIM) to the
DLC3.
(b) Turn the power switch ON (IG).
(c) Read the DTCs by following the prompts on the
intelligent tester screen.
HINT:
Refer to the tester operator's manual for further
details.
CLEAR DTC
(a) Connect the intelligent tester (with CAN VIM) to the
DLC3.
(b) Turn the power switch ON (IG).
(c) Erase the DTCs by following the prompts on the
tester screen.
HINT:
Refer to the intelligent tester operator's manual for
further details.

MP–19

MULTIPLEX COMMUNICATION – MULTIPLEX COMMUNICATION SYSTEM

DIAGNOSTIC TROUBLE CODE CHART
DTC No.

Detection Item

Trouble Area

See page

B1200

MPX Body ECU Stop

- Wire harness
- Driver side junction block

MP-18

B1207

Smart ECU Stop

- Wire harness
- Certification ECU

MP-21

B1210

Power ECU Stop

- Wire harness
- Power source control ECU

MP-24

B1214

Short to B+ in Door System
Communication Bus Malfunction

- Wire harness and connector in
BEAN
- A/C ECU
- Certification ECU*
- Combination meter
- Driver side junction block
- Gateway ECU
- Power source control ECU
- Tire pressure monitor ECU
- Transmission control ECU
- Transponder key ECU

MP-27

B1215

Short to GND in Door System
Communication Bus Malfunction

- Wire harness and connector in
BEAN
- A/C ECU
- Certification ECU*
- Combination meter
- Driver side junction block
- Gateway ECU
- Power source control ECU
- Tire pressure monitor ECU
- Transmission control ECU
- Transponder key ECU

MP-27

B1247

Tire Pressure Monitor Receiver
Communication Stop

- Wire harness
- Tire pressure warning ECU

MP-41

B1248

AVC-LAN Communication
Impossible

- Wire harness
- Multi-display

MP-45

B1260

"P" Position Control ECU Stop

- Wire harness
- Transponder control ECU

MP-47

B1262

A/C ECU Communication Stop

- Wire harness
- A/C ECU

MP-51

B1271

Combination Meter ECU
Communication Stop

- Wire harness
- Combination meter

MP-54

B1294

Immobiliser ECU Communication
Stop

- Wire harness
- Transponder key ECU

MP-57

HINT:
*: Equipped on smart key vehicles.

MP

MP–20

MULTIPLEX COMMUNICATION – MULTIPLEX COMMUNICATION SYSTEM

DTC

B1200

MPX Body ECU Stop

DESCRIPTION
This DTC is detected when communication between the main body ECU and gateway ECU stops for
more than 10 seconds.
DTC No.

DTC Detection Condition

Trouble Area

B1200

Body ECU communication stops

•
•

Driver side junction block
Wire harness

WIRING DIAGRAM
Transponder Key ECU

Driver Side Junction Block
Main Body ECU

MPX1

MPX2

A/C ECU

MPX1

MPX2+

MAIN

DOME
ECUB

GND

B126170E02

MP
INSPECTION PROCEDURE

1

INSPECT FUSE (DOME)
(a) Remove the DOME fuse from the engine room junction
block and relay block.
(b) Measure the resistance of the fuse.

MULTIPLEX COMMUNICATION – MULTIPLEX COMMUNICATION SYSTEM

MP–21

Standard resistance:
Below 1 Ω
NG

REPLACE FUSE

OK

2

CHECK WIRE HARNESS (DRIVER SIDE JUNCTION BLOCK - BATTERY AND BODY
GROUND)
(a) Disconnect the 1A and 1E junction block connectors.
(b) Measure the resistance and voltage of the wire harness
side connectors.
Standard resistance

Wire Harness Side

1A

1E

Tester Connection

Specified Condition

1E-17 (GND) - Body ground

Below 1 Ω

Standard voltage

GND

Tester Connection

Specified Condition

1A-30 (ECUB) - Body ground

10 to 14 V

NG
ECUB

REPAIR OR REPLACE HARNESS AND
CONNECTOR

B126171E01

OK

MP

MP–22

3

MULTIPLEX COMMUNICATION – MULTIPLEX COMMUNICATION SYSTEM

CHECK COMMUNICATION LINE

Wire Harness Side
Transponder Key ECU

Driver Side Junction Block
T5

1G

MPX1

MPX1
A/C ECU

Main Body ECU

A8

B5

MPX2+

MPX2
B126172E03

(a) Disconnect the 1G junction block connector.
(b) Disconnect the T5, A8 and B5 ECU connectors.
(c) Measure the resistance of the wire harness side
connectors.
Standard resistance
Tester Connection

Specified Condition

T5-17 (MPX1) - B5-15 (MPX2)

Below 1 Ω

A8-11 (MPX2+) - 1G-9 (MPX1)

Below 1 Ω

Result:
Result

Proceed to

Both are OK

A

One is OK

B

Both are NG

C

B

REPLACE DRIVER SIDE JUNCTION BLOCK

C

REPLACE DRIVER SIDE JUNCTION BLOCK
AND REPAIR OR REPLACE HARNESS AND
CONNECTOR

MP
A
REPLACE DRIVER SIDE JUNCTION BLOCK

MULTIPLEX COMMUNICATION – MULTIPLEX COMMUNICATION SYSTEM

DTC

B1207

MP–23

Smart ECU Stop

DESCRIPTION
This DTC is detected when communication between the certification ECU and gateway ECU stops for
more than 10 seconds.
DTC No.

DTC Detection Condition

Trouble Area

B1207

Certification ECU communication

•
•

Certification ECU
Wire harness

WIRING DIAGRAM
Transmission Control ECU

Certification ECU

MPX1

MPX1

Tire Pressure Monitor ECU

MPX1

MPX2

MAIN

DOME
+B1

E

B126173E01

MP
INSPECTION PROCEDURE

1

CHECK OPERATION
(a) With the key in your possession, push the lock button on
the door outside handle (entry lock operation). Check
that the key warning light illuminates or starts blinking.

MP–24

MULTIPLEX COMMUNICATION – MULTIPLEX COMMUNICATION SYSTEM

With the key in your possession, touch the inside of the
door outside handle (entry unlock operation). Check that
the key warning light illuminates or starts blinking.
OK:
Key warning light illuminates or starts blinking.
OK

Go to step 3

NG

2

CHECK WIRE HARNESS (CERTIFICATION ECU - BODY GROUND)
(a) Disconnect the S11 ECU connector.
(b) Measure the resistance and voltage of the wire harness
side connector.
Standard resistance

Wire Harness Side

S11

+B1

1 2 3 4 5 6 7 8 9

Tester Connection

Specified Condition

S11-17 (E) - Body ground

Below 1 Ω

E

10 11 12 13 14 15 16 17

18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40

Standard voltage
Tester Connection

Specified Condition

S11-1 (+B1) - Body ground

10 to 14 V

NG

REPAIR OR REPLACE HARNESS AND
CONNECTOR

B127139E01

OK

3

CHECK RESISTANCE OF COMMUNICATION LINE

Wire Harness Side

Certification ECU
S11

Transmission Control ECU
T4

Tire Pressure Monitor ECU
T11

MP
MPX1

MPX2

MPX1

MPX1
B130304E02

(a) Disconnect the S11, T4 and T11 ECU connectors.
(b) Measure the resistance of the wire harness side
connectors.

MULTIPLEX COMMUNICATION – MULTIPLEX COMMUNICATION SYSTEM

MP–25

Standard resistance
Tester Connection

Specified Condition

S11-31 (MPX1) - T4-19 (MPX1)

Below 1 Ω

S11-32 (MPX2) - T11-6 (MPX1)

Below 1 Ω

Result:
Result

Proceed to

Both are OK

A

One is OK

B

Both are NG

C

B

REPLACE CERTIFICATION ECU AND
REPAIR OR REPLACE HARNESS AND
CONNECTOR

C

REPAIR OR REPLACE HARNESS AND
CONNECTOR

A
REPLACE CERTIFICATION ECU

MP

MP–26

MULTIPLEX COMMUNICATION – MULTIPLEX COMMUNICATION SYSTEM

DTC

B1210

Power ECU Stop

DESCRIPTION
This DTC is detected when communication between the power source control ECU and gateway ECU
stops for more than 10 seconds.
DTC No.

DTC Detection Condition

Trouble Area

B1210

Power source control communication stops

•
•

Power source control ECU
Wire harness

WIRING DIAGRAM
Combination Meter

Power Source Control ECU

MPX-

MPX1

Gateway ECU

MPX2

MPD1

IG

from
IG1 Relay

from
Battery

AM1

AM2

GND2

B126176E02

MP
INSPECTION PROCEDURE

1

CHECK OPERATION
(a) Without depressing the brake pedal, push the power
switch repeatedly. Check that the power mode changes
between OFF, ON (ACC) and ON (IG) alternately.

MULTIPLEX COMMUNICATION – MULTIPLEX COMMUNICATION SYSTEM

MP–27

OK:
Key warning light illuminates or starts blinking
according to power modes.
OK

Go to step 3

NG

2

CHECK WIRE HARNESS (POWER SOURCE CONTROL ECU - BODY GROUND)
(a) Disconnect the P6 ECU connector.
(b) Measure the resistance and voltage of the wire harness
side connector.
Standard resistance

Wire Harness Side

P6

1 2 3 4 5 6 7 8 9

18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40

AM2

Specified Condition

P6-6 (GND2) - Body ground

Below 1 Ω

Standard voltage
10 11 12 13 14 15 16 17

GND2

Tester Connection

AM1

Tester Connection

Specified Condition

P6-33 (AM1) - Body ground

10 to 14 V

P6-32 (AM2) - Body ground

10 to 14 V

NG

REPAIR OR REPLACE HARNESS AND
CONNECTOR

B127139E02

OK

3

CHECK RESISTANCE OF COMMUNICATION LINE

Wire Harness Side

Power Source Control ECU

Gateway ECU

Combination Meter

P6

G1

C10

MPX1

MPX2

MPD1

MPX-

MP
B126177E01

(a) Disconnect the P6 and G1 ECU connectors.
(b) Disconnect the C10 meter connector.
(c) Measure the resistance between the wire harness side
connectors.

MP–28

MULTIPLEX COMMUNICATION – MULTIPLEX COMMUNICATION SYSTEM

Standard resistance
Tester Connection

Specified Condition

P6-7 (MPX1) - C10-25 (MPX-)

Below 1 Ω

P6-24 (MPX2) - G1-3 (MPD1)

Below 1 Ω

Result:
Result

Proceed to

Both are OK

A

One is OK

B

Both are NG

C

B

REPLACE POWER SOURCE CONTROL ECU
AND REPAIR OR REPLACE HARNESS AND
CONNECTOR

C

REPAIR OR REPLACE HARNESS AND
CONNECTOR

A
REPLACE POWER SOURCE CONTROL ECU

MP

MULTIPLEX COMMUNICATION – MULTIPLEX COMMUNICATION SYSTEM

MP–29

DTC

B1214

Short to B+ in Door System Communication
Bus Malfunction

DTC

B1215

Short to GND in Door System Communication
Bus Malfunction

DESCRIPTION
The air conditioning (A/C) ECU, body ECU (built into driver side junction block), combination meter,
certification ECU*, power source control ECU, tire pressure monitor ECU, transmission control ECU,
transponder key ECU and gateway ECU are connected to the Body Electronics Area Network (BEAN).
The gateway ECU monitors the BEAN. If there is a B+ or GND short in the BEAN, the gateway ECU sets
the DTC and the related system(s) do not operate.
DTC

DTC Detection Condition

Trouble Area

B1214

B+ short in BEAN

B1215

GND short in BEAN

•
•
•
•
•
•
•
•
•
•

A/C ECU
Certification ECU*
Combination meter
Driver side junction block
Gateway ECU
Power source control ECU
Tire pressure monitor ECU
Transmission control ECU
Transponder key ECU
Wire harness and connector in BEAN

HINT:
*: Equipped on smart key vehicles.

MP

MP–30

MULTIPLEX COMMUNICATION – MULTIPLEX COMMUNICATION SYSTEM

WIRING DIAGRAM

Gateway ECU
Combination Meter

Power Source Control ECU

MPD1

Certification ECU*1

Tire Pressure Monitor ECU

Transmission Control ECU

*2

Transponder Key ECU

A/C ECU

Driver Side Junction Block

MP

MPD2
*1: w/ Smart Key System
*2: w/o Smart Key System
E116661E10

MULTIPLEX COMMUNICATION – MULTIPLEX COMMUNICATION SYSTEM

MP–31

INSPECTION PROCEDURE

1

CHECK A/C ECU

Wire Harness Side
A8

(a)
(b)
(c)
(d)
(e)

Turn the power switch OFF.
Disconnect the A/C ECU connector.
Connect the intelligent tester to the DLC3.
Turn the power switch ON (IG).
Clear and check DTCs.
Result

DTC

Conclusion

Proceed to

B1214 or B1215 is
present

A/C ECU is OK

A

B1214 and B1215 are not
present

A/C ECU is
malfunctioning

B

B

REPLACE A/C ECU

B126184E01

A

2

CHECK TRANSMISSION CONTROL ECU
(a)
(b)
(c)
(d)
(e)

Wire Harness Side

T4

Turn the power switch OFF .
Connect the A/C ECU connector.
Disconnect the transmission control ECU connector.
Turn the power switch ON (IG).
Clear and check DTCs.
Result

DTC

Conclusion

Proceed to

B1214 or B1215 is
present

Transmission control
ECU is OK

A

B1214 and B1215 are not
present

Transmission control
ECU is malfunctioning

B

B

REPLACE TRANSMISSION CONTROL ECU

B126181E01

A

MP

MP–32

3

MULTIPLEX COMMUNICATION – MULTIPLEX COMMUNICATION SYSTEM

CHECK WIRE HARNESS (TRANSMISSION CONTROL ECU - A/C ECU)
(a) Turn the power switch OFF.
(b) Disconnect the transmission control ECU connector and
A/C ECU connector.
(c) Turn the power switch ON (IG).
(d) Clear and check DTCs.
Result

Wire Harness Side

A/C ECU
A8

DTC

Conclusion

Proceed to

B1214 or B1215 is
present

Wire harness is OK

A

B1214 and B1215 are not
present

Wire harness is short
circuited

B

B

Go to step 8

Transmission Control ECU
T4

B127147E02

A

4

CHECK POWER SOURCE CONTROL ECU
(a) Turn the power switch OFF.
(b) Connect the A/C ECU connector and transmission
control ECU connector.
(c) Disconnect the power source control ECU connector.
(d) Turn the power switch ON (IG).
(e) Clear and check DTCs.
Result

Wire Harness Side

P6

MP

DTC

Conclusion

Proceed to

B1214 or B1215 is
present

Power source control
ECU is OK

A

B1214 and B1215 are not
present

Power source control
ECU is malfunctioning

B

B
E116654E10

A

REPLACE POWER SOURCE CONTROL ECU

MULTIPLEX COMMUNICATION – MULTIPLEX COMMUNICATION SYSTEM

5

MP–33

CHECK WIRE HARNESS (POWER SOURCE CONTROL ECU - TRANSMISSION CONTROL
ECU)
(a) Turn the power switch OFF.
(b) Disconnect the power source control ECU connector and
transmission control ECU connector.
(c) Turn the power switch ON (IG).
(d) Clear and check DTCs.
Result

Wire Harness Side

Power Source Control ECU
P6

DTC

Conclusion

Proceed to

B1214 or B1215 is
present

Wire harness is OK

A

B1214 and B1215 are not
present

Wire harness is short
circuited

B

B

Go to step 12

Transmission Control ECU
T4

B127148E01

A

MP

MP–34

6

MULTIPLEX COMMUNICATION – MULTIPLEX COMMUNICATION SYSTEM

CHECK WIRE HARNESS (GATEWAY ECU - POWER SOURCE CONTROL ECU)
(a) Turn the power switch OFF.
(b) Connect the transmission control ECU connector.
(c) Disconnect the power source control ECU connector and
gateway ECU connector.
(d) Measure the resistance and voltage of the gateway ECU
connector terminal.
Standard resistance

Wire Harness Side

Gateway ECU
G1

Tester Connection

Specified Condition

G1-3 (MPD1) - Body ground

10 kΩ or higher

Standard voltage

MPD1
Power Source Control ECU

MPX2
B127150E02

MP

Condition

Specified Condition

G1-3 (MPD1) - Body
ground

Power switch ON (IG)

Below 1 V

NG

P6

OK

Tester Connection

REPAIR OR REPLACE HARNESS AND
CONNECTOR

MULTIPLEX COMMUNICATION – MULTIPLEX COMMUNICATION SYSTEM

7

MP–35

CHECK WIRE HARNESS (GATEWAY ECU - A/C ECU)
(a) Turn the power switch OFF.
(b) Connect the power source control ECU connector.
(c) Disconnect the A/C ECU connector and gateway ECU
connector.
(d) Measure the resistance and voltage of the gateway ECU
connector terminal.
Standard resistance

Wire Harness Side

Gateway ECU
G1

Tester Connection

Specified Condition

G1-12 (MPD2) - Body ground

10 kΩ or higher

Standard voltage

MPD2
A/C ECU

Tester Connection

Condition

Specified Condition

G1-12 (MPD2) - Body
ground

Power switch ON (IG)

Below 1 V

NG

A8

REPAIR OR REPLACE HARNESS AND
CONNECTOR

MPX+
B127149E02

OK
REPLACE GATEWAY ECU

MP

MP–36

8

MULTIPLEX COMMUNICATION – MULTIPLEX COMMUNICATION SYSTEM

CHECK DRIVER SIDE JUNCTION BLOCK
(a) Turn the power switch OFF.
(b) Connect the A/C ECU connector and transmission
control ECU connector.
(c) Disconnect the 1G driver side junction block connector
and B5 main body ECU connector.
(d) Turn the power switch ON (IG).
(e) Clear and check DTCs.
Result

Wire Harness Side

Driver Side Junction Block
1G

B5

B127151E02

MP

Conclusion

Proceed to

B1214 or B1215 is
present

Driver side junction block
is OK

A

B1214 and B1215 are not
present

Driver side junction block
is malfunctioning

B

B

Main Body ECU

A

DTC

REPLACE DRIVER SIDE JUNCTION BLOCK

MULTIPLEX COMMUNICATION – MULTIPLEX COMMUNICATION SYSTEM

9

MP–37

CHECK WIRE HARNESS (DRIVER SIDE JUNCTION BLOCK - A/C ECU)
(a) Turn the power switch OFF.
(b) Connect the B5 ECU connector.
(c) Disconnect the 1G driver side junction block connector
and A/C ECU connector.
(d) Turn the power switch ON (IG).
(e) Clear and check DTCs.
Result

Wire Harness Side

A/C ECU
A8

DTC

Conclusion

Proceed to

B1214 or B1215 is
present

Wire harness is OK

A

B1214 and B1215 are not
present

Wire harness is short
circuited

B

B

REPAIR OR REPLACE HARNESS AND
CONNECTOR

Driver Side Junction Block
1G

B127152E03

A

10

CHECK TRANSPONDER KEY ECU
(a) Turn the power switch OFF.
(b) Connect the driver side junction block connector and A/C
ECU connector.
(c) Disconnect the transponder key ECU connector.
(d) Turn the power switch ON (IG).
(e) Clear and check DTCs.
Result

Wire Harness Side

T5

DTC

Conclusion

Proceed to

B1214 or B1215 is
present

Transponder key ECU is
OK

A

B1214 and B1215 are not
present

Transponder key ECU is
malfunctioning

B

B
B127153E01

A

REPLACE TRANSPONDER KEY ECU

MP

MP–38

11

MULTIPLEX COMMUNICATION – MULTIPLEX COMMUNICATION SYSTEM

CHECK WIRE HARNESS (TRANSPONDER KEY ECU - DRIVER SIDE JUNCTION BLOCK)
(a) Turn the power switch OFF.
(b) Disconnect the transponder key ECU connector and B5
ECU connector.
(c) Turn the power switch ON (IG).
(d) Clear and check DTCs.
Result

Wire Harness Side

Main Body ECU
B5

DTC

Conclusion

Proceed to

B1214 or B1215 is
present

Wire harness is OK

A

B1214 and B1215 are not
present

Wire harness is short
circuited

B

B

REPAIR OR REPLACE HARNESS AND
CONNECTOR (TRANSPONDER KEY ECU DRIVER SIDE JUNCTION BLOCK)

Transponder Key ECU
T5

B127154E02

A
REPAIR OR REPLACE HARNESS AND CONNECTOR (TRANSPONDER KEY ECU TRANSMISSION CONTROL ECU)

MP

MULTIPLEX COMMUNICATION – MULTIPLEX COMMUNICATION SYSTEM

12

MP–39

CHECK COMBINATION METER
(a) Turn the power switch OFF.
(b) Connect the power source control ECU connector and
transmission control ECU connector.
(c) Disconnect the C10 meter connector.
(d) Turn the ignition switch ON (IG).
(e) Clear and check DTCs.
Result

Wire Harness Side

C10

DTC

Conclusion

Proceed to

B1214 or B1215 is
present

Combination meter is OK

A

B1214 and B1215 are not
present

Combination meter is
malfunctioning

B

B

REPLACE COMBINATION METER

B126419E02

A

13

CHECK WIRE HARNESS (COMBINATION METER - POWER SOURCE CONTROL ECU)
(a) Turn the power switch OFF.
(b) Disconnect the C10 combination meter and power
source control ECU connector.
(c) Turn the power switch ON (IG).
(d) Clear and check DTCs.
Result

Wire Harness Side

Combination Meter
C10

DTC

Conclusion

Proceed to

B1214 or B1215 is
present

Wire harness is OK

A

B1214 and B1215 are not
present

Wire harness is short
circuited

B

B

REPAIR OR REPLACE HARNESS AND
CONNECTOR

Power Source Control ECU

MP

P6

B130297E02

A

MP–40

MULTIPLEX COMMUNICATION – MULTIPLEX COMMUNICATION SYSTEM

14

CHECK TIRE PRESSURE WARNING ECU
(a) Turn the power switch OFF.
(b) Connect the C10 meter connector and power source
control ECU connector.
(c) Disconnect the tire pressure monitor ECU connector.
(d) Turn the power switch ON (IG).
(e) Clear and check DTCs.
Result

Wire Harness Side

T11

DTC

Conclusion

Proceed to

B1214 or B1215 is
present

Tire pressure monitor
ECU is OK

A

B1214 and B1215 are not
present

Tire pressure monitor
ECU is malfunctioning

B

B

REPLACE TIRE PRESSURE WARNING ECU

B130300E01

A

15

CHECK WIRE HARNESS (TIRE PRESSURE WARNING ECU - COMBINATION METER)
(a) Turn the power switch OFF.
(b) Disconnect the tire pressure monitor ECU connector and
C10 meter connector.
(c) Turn the power switch ON (IG).
(d) Clear and check DTCs.
Result

Wire Harness Side

Tire Pressure Monitor ECU

T11

DTC

Conclusion

Proceed to

B1214 or B1215 is
present

Wire harness is OK

A

B1214 and B1215 are not
present

Wire harness is short
circuited

B

B

Combination Meter
C10

MP

B130301E01

A

REPAIR OR REPLACE HARNESS AND
CONNECTOR

MULTIPLEX COMMUNICATION – MULTIPLEX COMMUNICATION SYSTEM

16

MP–41

CONFIRM EQUIPMENT
Equipment
Equipment

Proceed to

With smart key system

A

Without smart key system

B

B

REPAIR OR REPLACE HARNESS AND
CONNECTOR (TIRE PRESSURE MONITOR
ECU - TRANSMISSION CONTROL ECU)

A

17

CHECK CERTIFICATION ECU
(a) Turn the power switch OFF.
(b) Connect the C10 meter connector and tire pressure
monitor ECU connector.
(c) Disconnect the certification ECU connector.
(d) Turn the power switch ON (IG).
(e) Clear and check DTCs.
Result

Wire Harness Side

S11

DTC

Conclusion

Proceed to

B1214 or B1215 is
present

Certification ECU is OK

A

B1214 and B1215 are not
present

Certification ECU is
malfunctioning

B

B

REPLACE CERTIFICATION ECU

E116654E11

A

MP

MP–42

MULTIPLEX COMMUNICATION – MULTIPLEX COMMUNICATION SYSTEM

18

CHECK WIRE HARNESS (CERTIFICATION ECU - TIRE PRESSURE MONITOR ECU)
(a) Turn the power switch OFF.
(b) Disconnect the certification ECU connector and tire
pressure monitor ECU connector.
(c) Turn the power switch ON (IG).
(d) Clear and check DTCs.
Result

Wire Harness Side

Certification ECU
S11

DTC

Conclusion

Proceed to

B1214 or B1215 is
present

Wire harness is OK

A

B1214 and B1215 are not
present

Wire harness is short
circuited

B

B

REPAIR OR REPLACE HARNESS AND
CONNECTOR (CERTIFICATION ECU - TIRE
PRESSURE MONITOR ECU)

Transmission Control ECU
T4

B127148E02

A
REPAIR OR REPLACE HARNESS AND CONNECTOR (CERTIFICATION ECU - TRANSMISSION
CONTROL ECU)

MP

MULTIPLEX COMMUNICATION – MULTIPLEX COMMUNICATION SYSTEM

DTC

B1247

MP–43

Tire Pressure Monitor Receiver Communication
Stop

DESCRIPTION
This DTC is detected when the communication between the tire pressure warning ECU and gateway ECU
stops for more than 10 seconds.
DTC No.

DTC Detection Condition

Trouble Area

B1247

Tire pressure monitor receiver communication
stops

•
•

Tire pressure warning ECU
Wire harness

WIRING DIAGRAM

Tire Pressure Warning ECU

ECU-IG

from

IG

IG1 Relay

Combination Meter

MPX+

MPX1

Certification ECU*1
Transmission Control ECU*2
MPX2*1
MPX1*2

MPX2

MP

GND
*1: w/ Smart Key System
*2: w/o Smart Key System
B130306E03

MP–44

MULTIPLEX COMMUNICATION – MULTIPLEX COMMUNICATION SYSTEM

INSPECTION PROCEDURE

1

INSPECT FUSE (ECU-IG)
(a) Remove the ECU-IG fuse from the driver side junction
block.
(b) Measure the resistance of the fuse.
Standard resistance:
Below 1 Ω
NG

REPLACE FUSE

OK

2

CHECK WIRE HARNESS (TIRE PRESSURE WARNING ECU - BATTERY AND BODY
GROUND)
(a) Disconnect the T11 ECU connector.
(b) Turn the power switch ON (IG).
(c) Measure the voltage and resistance of the wire harness
side connector.
Standard voltage

Wire Harness Side
T11

1

2

3

7

8

9 10 11 12

4

5

Tester Connection

Condition

Specified Condition

T11-1 (IG) - Body
ground

Power switch ON (IG)

10 to 14 V

6

Standard resistance

IG

Tester Connection

Specified Condition

T11-7 (GND) - Body ground

Below 1 Ω

NG
B108903E09

OK

MP

REPAIR OR REPLACE HARNESS AND
CONNECTOR

MULTIPLEX COMMUNICATION – MULTIPLEX COMMUNICATION SYSTEM

3

MP–45

CHECK RESISTANCE OF COMMUNICATION LINE
*2: w/o Smart Key

*1: w/ Smart Key

Wire Harness Side

Certification ECU*1

Transmission Control ECU*2

S11

T11

T4

MPX1

MPX2

Tire Pressure Warning ECU

MPX1
B130304E05

Wire Harness Side

*1: w/ Smart Key System (for Door Lock)

*2: w/o Smart Key System (for Door Lock)

Tire Pressure Warning ECU

Combination Meter

T11

C10

MPX+
MPX2

MPX1

Transmission Control ECU*2

Certification ECU*1

T4

S11

MP

MPX1

MPX2

B131912E02

(a) Disconnect the T11, S11*1 and T4*2 ECU connectors.
(b) Disconnect the C10 meter connector.
(c) Measure the resistance of the wire harness side
connector.
Standard resistance
Tester Connection

Specified Condition

T11-6 (MPX1) - S11-32 (MPX2)*1

Below 1 Ω

MP–46

MULTIPLEX COMMUNICATION – MULTIPLEX COMMUNICATION SYSTEM
Tester Connection

Specified Condition

T11-6 (MPX1) - T4-19 (MPX1)*2

Below 1 Ω

T11-12 (MPX2) - C10-24 (MPX+)

Below 1 Ω

HINT:
*1: w/ Smart key system (for door lock)
*2: w/o Smart key system (for door lock)
Result:
Result

Proceed to

Both are OK

A

One is OK

B

Both are NG

C

B

REPLACE TIRE PRESSURE WARNING ECU
AND REPAIR OR REPLACE HARNESS AND
CONNECTOR

C

REPAIR OR REPLACE HARNESS AND
CONNECTOR

A
REPLACE TIRE PRESSURE WARNING ECU

MP

MULTIPLEX COMMUNICATION – MULTIPLEX COMMUNICATION SYSTEM

DTC

B1248

MP–47

AVC-LAN Communication Impossible

DESCRIPTION
This DTC is detected when communication is impossible between the multi-display and gateway ECU.
DTC No.

DTC Detection Condition

Trouble Area

B1248

AVC-LAN communication is impossible

•
•

Multi-display
Wire harness

WIRING DIAGRAM

Gateway ECU

Multi-display

GTX+

TX1+

GTX-

TX1-

B126178E01

MP

INSPECTION PROCEDURE

1

CHECK OPERATION
(a) Check that the radio and player switch can operate
normally.
OK:
Radio and player switch can operate normally.

MP–48

MULTIPLEX COMMUNICATION – MULTIPLEX COMMUNICATION SYSTEM

NG

GO TO AUDIO SYSTEM

OK

2

CHECK RESISTANCE OF COMMUNICATION LINE

Wire Harness Side

*1: w/ Television Camera

Multi-display*1
M13

TX1+

*2: w/o Television Camera

M14

TX1-

Gateway ECU

Multi-display*2
G1

TX1+

TX1-

GTX+

GTXB131788E02

(a) Disconnect the G1 ECU connector.
(b) Disconnect the M13*1 or M14*2 display connector.
(c) Measure the resistance between the wire harness side
connectors.
Standard resistance
Tester Connection

Specified Condition

M13-4 (TX1+)*1 - G1-6 (GTX+)

Below 1 Ω

M13-4 (TX1+)*1 - G1-6 (GTX+)

Below 1 Ω

M14-5 (TX1-)*2 - G1-21 (GTX-)

Below 1 Ω

M14-5 (TX1-)*2 - G1-21 (GTX-)

Below 1 Ω

HINT:
*1: w/ Television camera
*2: w/o Television camera
NG
OK

MP REPLACE MULTI-DISPLAY

REPAIR OR REPLACE HARNESS AND
CONNECTOR

MULTIPLEX COMMUNICATION – MULTIPLEX COMMUNICATION SYSTEM

DTC

B1260

MP–49

"P" Position Control ECU Stop

DESCRIPTION
This DTC is detected when communication between the transmission control ECU and gateway ECU
stops for more than 10 seconds.
DTC No.

DTC Detection Condition

Trouble Area

B1260

Transmission control ECU communication
stops

•
•

Transponder control ECU
Wire harness

WIRING DIAGRAM
Transmission Control ECU

Certification ECU*1, Tire Pressure Monitor ECU*2

MPX1

MPX1

Transponder Key ECU

MPX2

MPX2

To IGCT Relay
(HEV Fuse)

+B

*1: With Smart Key
*2: Without Smart Key
E1

B126180E02

MP
INSPECTION PROCEDURE

1

INSPECT FUSE (HEV)
(a) Remove the HEV fuse from the engine room junction
block.
(b) Measure the resistance.

MP–50

MULTIPLEX COMMUNICATION – MULTIPLEX COMMUNICATION SYSTEM

Standard resistance:
Below 1 Ω
NG

REPLACE FUSE

OK

2

CHECK WIRE HARNESS (TRANSMISSION CONTROL ECU - BODY GROUND)
(a) Disconnect the T4 ECU connector.
(b) Measure the resistance and voltage between the wire
harness side connector.
Standard resistance

Wire Harness Side
T4

Tester Connection

Specified Condition

T4-15 (E1) - Body ground

Below 1 Ω

Standard voltage

+B

E1

MP

Condition

Specified Condition

T4-1 (+B) - Body ground

Power switch ON (IG)

10 to 14 V

NG

B126181E02

OK

Tester Connection

REPAIR OR REPLACE HARNESS AND
CONNECTOR

MULTIPLEX COMMUNICATION – MULTIPLEX COMMUNICATION SYSTEM

3

MP–51

CHECK RESISTANCE OF COMMUNICATION LINE

Wire Harness Side

Transponder Key ECU

Transmission Control ECU

T5

T4

MPX2

MPX1

MPX2
Tire Pressure Monitor ECU*2

Certification ECU*1

S11

T11

MPX1
*1: w/ Smart Key System (for Door Lock)

MPX1
*2: w/o Smart Key System (for Door Lock)
B131880E01

(a) Disconnect the T4, T5 and S11*1 or T11*2 ECU
connectors.
(b) Measure the resistance of the wire harness side
connectors.
Standard resistance
Tester Connection

Specified Condition

T4-18 (MPX2) - T5-16 (MPX2)

Below 1 Ω

T4-19 (MPX1) - S11-31 (MPX1)*1

Below 1 Ω

T4-19 (MPX1) - T11-6 (MPX1)*2

Below 1 Ω

HINT:
*1: w/ Smart key system (for door lock)
*2: w/o Smart key system (for door lock)
Result:
Result

Proceed to

Both are OK

A

One is OK

B

Both are NG

C

B

REPLACE TRANSMISSION CONTROL ECU
AND REPAIR OR REPLACE HARNESS AND
CONNECTOR

MP

MP–52

MULTIPLEX COMMUNICATION – MULTIPLEX COMMUNICATION SYSTEM

C
A
REPLACE TRANSMISSION CONTROL ECU

MP

REPAIR OR REPLACE HARNESS AND
CONNECTOR

MULTIPLEX COMMUNICATION – MULTIPLEX COMMUNICATION SYSTEM

DTC

B1262

MP–53

A/C ECU Communication Stop

DESCRIPTION
This DTC is detected when communication between the A/C ECU and gateway ECU stops for more than
10 seconds.
DTC No.

DTC Detection Condition

Trouble Area

B1262

A/C ECU communication stops

•
•

A/C ECU
Wire harness

WIRING DIAGRAM
Gateway ECU
Driver Side
Junction Block

A/C ECU

MPD2

MPX+

Body ECU
MPX1

MPX2+

MAIN

DC/DC

ECU-B
+B

GND

B126183E01

MP
INSPECTION PROCEDURE

1

CHECK OPERATION
(a) Check that the A/C switch can operate the air conditioner
normally.

MP–54

MULTIPLEX COMMUNICATION – MULTIPLEX COMMUNICATION SYSTEM

OK:
A/C switch can operate the air conditioner
normally.
OK

Go to step 3

NG

2

CHECK WIRE HARNESS (A/C ECU - BODY GROUND)
(a) Disconnect the A8 ECU connector.
(b) Measure the resistance and voltage of the wire harness
side connector.
Standard resistance

Wire Harness Side
A8

Tester Connection

Specified Condition

A8-1 (GND) - Body ground

Below 1 Ω

Standard voltage

+B

GND

Tester Connection

Specified Condition

A8-6 (+B) - Body ground

10 to 14 V

NG

REPAIR OR REPLACE HARNESS AND
CONNECTOR

B126184E02

OK

3

CHECK RESISTANCE OF COMMUNICATION LINE

Wire Harness Side
A/C ECU

Gateway ECU

Driver Side Junction Block

G1

1G

A8
MPX+

MP

MPX2+

MPD2

MPX1

B126185E01

(a) Disconnect the A8 and G1 ECU connectors.
(b) Disconnect the 1G junction block connector.
(c) Measure the resistance of the wire harness side
connectors.

MULTIPLEX COMMUNICATION – MULTIPLEX COMMUNICATION SYSTEM

MP–55

Standard resistance
Tester Connection

Specified Condition

A8-3 (MPX+) - G1-12 (MPD2)

Below 1 Ω

A8-11 (MPX2+) - 1G-9 (MPX1)

Below 1 Ω

Result:
Result

Proceed to

Both are OK

A

One is OK

B

Both are NG

C

B

REPLACE A/C ECU AND REPAIR OR
REPLACE HARNESS AND CONNECTOR

C

REPAIR OR REPLACE HARNESS AND
CONNECTOR

A
REPLACE A/C ECU

MP

MP–56

MULTIPLEX COMMUNICATION – MULTIPLEX COMMUNICATION SYSTEM

DTC

B1271

Combination Meter ECU Communication Stop

DESCRIPTION
This DTC is detected when communication between the combination meter and gateway ECU stops for
more than 10 seconds.
DTC No.

DTC Detection Condition

Trouble Area

B1271

Combination meter ECU communication
stops

•
•

Combination meter
Wire harness

WIRING DIAGRAM
Power Source Control ECU

Combination Meter

MPX1

MPX-

Tire Pressure Monitor ECU

MPX+

MPX2

DOME

from Battery
B126186E03

MP
INSPECTION PROCEDURE

1

CHECK OPERATION
(a) Check that the indicator (READY) on the combination
meter illuminates when the hybrid vehicle control system
is operating (power switch ON (READY)).

MULTIPLEX COMMUNICATION – MULTIPLEX COMMUNICATION SYSTEM

MP–57

OK:
Indicator can operate properly.
OK

Go to step 3

NG

2

CHECK WIRE HARNESS (COMBINATION METER - BODY GROUND)
(a) Disconnect the C10 meter connector.
(b) Measure the resistance and voltage of the wire harness
side connector.
Standard resistance

Wire Harness Side

C10

Tester Connection

Specified Condition

C10-14 - Body ground

Below 1 Ω

Standard voltage
Tester Connection

Specified Condition

C10-21 - Body ground

10 to 14 V

NG

REPAIR OR REPLACE HARNESS AND
CONNECTOR

B126419E03

OK

3

CHECK RESISTANCE OF COMMUNICATION LINE

Wire Harness Side

Combination Meter

C10

Tire Pressure Monitor ECU

P6

T11

MPX+

MPX-

Power Source Control ECU

MPX2

MPX1

MP
B131881E01

(a) Disconnect the C10 meter connector.
(b) Disconnect the P6 and T11 ECU connectors.
(c) Measure the resistance of the wire harness side
connectors.
Standard resistance
Tester Connection

Specified Condition

C10-24 (MPX+) - T11-12 (MPX2)

Below 1 Ω

MP–58

MULTIPLEX COMMUNICATION – MULTIPLEX COMMUNICATION SYSTEM
Tester Connection

Specified Condition

C10-25 (MPX-) - P6-7 (MPX1)

Below 1 Ω

Result:

A
REPLACE COMBINATION METER

MP

Result

Proceed to

Both are OK

A

One is OK

B

Both are NG

C

B

REPLACE COMBINATION METER AND
REPAIR OR REPLACE HARNESS AND
CONNECTOR

C

REPAIR OR REPLACE HARNESS AND
CONNECTOR

MULTIPLEX COMMUNICATION – MULTIPLEX COMMUNICATION SYSTEM

DTC

B1294

MP–59

Immobiliser ECU Communication Stop

DESCRIPTION
This DTC is detected when communication between the transponder key ECU and gateway ECU stops
for more than 10 seconds.
DTC No.

DTC Detection Condition

Trouble Area

B1294

Transponder key ECU communication stops

•
•

Transponder key ECU
Wire harness

WIRING DIAGRAM
Transmission Control ECU

Transponder Key ECU

MPX2

MPX2
Driver Side Junction Block
Main Body ECU

MPX1
MPX2
IGN
from Battery

IG

GND

B126189E02

MP
INSPECTION PROCEDURE

1

INSPECT FUSE (IGN)
(a) Remove the IGN fuse from the driver side junction block.
(b) Measure the resistance of the fuse.
Standard resistance:
Below 1 Ω

MP–60

MULTIPLEX COMMUNICATION – MULTIPLEX COMMUNICATION SYSTEM

NG

REPLACE FUSE

OK

2

CHECK WIRE HARNESS (TRANSPONDER KEY ECU - BODY GROUND)
(a) Disconnect the T5 ECU connector.
(b) Measure the resistance and voltage of the wire harness
side connectors.
Standard resistance

Wire Harness Side

T5

IG

Tester Connection

Specified Condition

T5-22 (GND) - Body ground

Below 1 Ω

Standard voltage
Tester Connection

Condition

Specified Condition

T5-4 (IG) - Body ground

Power switch ON (IG)

10 to 14 V

NG

REPAIR OR REPLACE HARNESS AND
CONNECTOR

GND
B127153E02

OK

3

CHECK RESISTANCE OF COMMUNICATION LINE

Wire Harness Side
Transmission Control ECU

Transponder Key ECU

B5

T5

T4

MPX2

Body ECU

MPX2

MPX1

MPX2

B126190E01

MP

(a) Disconnect the T4, T5 and B5 ECU connectors.
(b) Measure the resistance of the wire harness side
connectors.
Standard resistance
Tester Connection

Specified Condition

T5-17 (MPX1) - B5-15 (MPX2)

Below 1 Ω

T5-16 (MPX2) - T4-18 (MPX2)

Below 1 Ω

MULTIPLEX COMMUNICATION – MULTIPLEX COMMUNICATION SYSTEM

MP–61

Result:
Result

Proceed to

Both are OK

A

One is OK

B

Both are NG

C

B

REPLACE TRANSPONDER KEY ECU AND
REPAIR OR REPLACE HARNESS AND
CONNECTOR

C

REPAIR OR REPLACE HARNESS AND
CONNECTOR

A
REPLACE TRANSPONDER KEY ECU

MP