Networking. Dtc U1002 Lost Communication With Gateway Module (Ms Bus)

The main body ECU (multiplex network body ECU) stores this DTC when no signals can be received from the ECUs that have been memorized as those connected to the CAN MS bus.
When the main body ECU (multiplex network body ECU) receives a response signal from the ECUs connected to the CAN MS bus, the main body ECU (multiplex network body ECU) recognizes and memorizes that the ECU is connected to the CAN MS bus. Based on this memorized data, the main body ECU (multiplex network body ECU) monitors for malfunctions in the ECUs connected to the CAN MS bus when communicating with those ECUs. If the main body ECU (multiplex network body ECU) cannot receive response signals from the ECUs that have been memorized as those connected to the CAN MS bus, the main body ECU (multiplex network body ECU) determines that a malfunction exists.
If 2 or more DTCs are output during the DTC check, one side of the CAN branch wire may be open (one side of the CANH [CAN branch wire]/CANL [CAN branch wire] of the ECU and/or sensor is open).

DTC Code	DTC Detection Condition	Trouble Area
U1002 (CAN MS BUS)	Lost communication with the gateway module (MS bus).	MS bus circuit Main body ECU (multiplex network body ECU) CAN main wire or connector Front power seat switch RH CAN branch wire or connector1 Multiplex tilt and telescopic ECU CAN branch wire or connector2 Driving support switch control ECU CAN branch wire or connector3 Main body ECU (multiplex network body ECU) Front power seat switch RH1 Multiplex tilt and telescopic ECU2 Driving monitor switch control ECU3 Rear television camera assembly*4 No. 2 junction connector No. 5 junction connector

*1: w/ Seat Position Memory
*2: for Power Tilt and Power Telescopic Steering Column
*3: w/ Multi-function Switch
*4: w/ Parking Assist Monitor System (for Camera built-in ECU)

WIRING DIAGRAM

Land Cruiser, Land Cruiser Prado. Grj150 Trj150,155 Kdj150,155 Lj150, Gdj150,155.Networking.Lin Communication System.
Dtc
U1002 Lost Communication With Gateway Module (Ms Bus)

INSPECTION PROCEDURE

HINT:

Operating the engine switch, any switches or any doors triggers related ECU and sensor communication with the CAN, which causes resistance variation.

1.DISCONNECT CABLE FROM NEGATIVE BATTERY TERMINAL

Disconnect the cable from the negative (-) battery terminal before measuring the resistances of the CAN main wire and the CAN branch wire.
CAUTION:
Wait at least 90 seconds after disconnecting the cable from the negative (-) battery terminal to disable the airbag system.
NOTICE:
1. After turning the engine switch off, waiting time may be required before disconnecting the cable from the battery terminal. Therefore, make sure to read the disconnecting the cable from the battery terminal notice before proceeding with work (LandCruiser RM000003YMD00TX.html).
2. When disconnecting the cable, some systems need to be initialized after the cable is reconnected (LandCruiser RM000003YMF011X.html).

NEXT

2.CHECK CAN BUS WIRE (CHECK CAN MAIN WIRE FOR DISCONNECTION, CHECK BUS LINE FOR SHORT)

Measure the resistance according to the value(s) in the table below.

Standard Resistance:

Tester Connection	Switch Condition	Specified Condition	Resistance: Malfunction
G103-3 (CANP) - G103-2 (CANN)	Engine switch off	54 to 69 Ω	Below 53 Ω: Short in line
G103-3 (CANP) - G103-2 (CANN)	Engine switch off	54 to 69 Ω	Higher than 70 Ω: Open in CAN main bus line
G103-3 (CANP) - G48-16 (BAT)	Engine switch off	6 kΩ or higher	Below 6 kΩ: +B short
G103-2 (CANN) - G48-16 (BAT)	Engine switch off	6 kΩ or higher	Below 6 kΩ: +B short
G103-3 (CANP) - G48-4 (CG)	Engine switch off	200 Ω or higher	Below 200 Ω: Ground short
G103-2 (CANN) - G48-4 (CG)	Engine switch off	200 Ω or higher	Below 200 Ω: Ground short

Text in Illustration
*a	Component with harness connector (No. 5 Junction Connector)
*b	Front view of DLC3

Result
Result	Proceed to
NG Open in CAN main bus line	A
NG Short in line +B short Ground short	B
OK	C

Go to step 9

Go to step 27

A

3.CHECK FOR OPEN IN CAN BUS MAIN WIRE (NO. 2 JUNCTION CONNECTOR - MAIN BODY ECU)

Disconnect the G133 No. 2 junction connector.

Measure the resistance according to the value(s) in the table below.
Standard Resistance:
Tester Connection
Switch Condition
Specified Condition
G133-4 (CANH) - G133-15 (CANL)
Engine switch off
108 to 132 Ω
Text in Illustration
*a
Rear view of wire harness connector
(to No. 2 Junction Connector)

Go to step 5

OK

4.CHECK FOR OPEN IN CAN BUS MAIN WIRE (NO. 2 JUNCTION CONNECTOR - NO. 5 JUNCTION CONNECTOR)

Measure the resistance according to the value(s) in the table below.
Standard Resistance:
Tester Connection
Switch Condition
Specified Condition
G133-6 (CANH) - G133-17 (CANL)
Engine switch off
108 to 132 Ω
Text in Illustration
*a
Rear view of wire harness connector
(to No. 2 Junction Connector)

Go to step 7

REPLACE NO. 2 JUNCTION CONNECTOR

5.CONNECT CONNECTOR

Reconnect the G133 No. 2 junction connector.

NEXT

6.CHECK FOR OPEN IN CAN BUS MAIN WIRE (MAIN BODY ECU - NO. 2 JUNCTION CONNECTOR)

Disconnect the G63 main body ECU (multiplex network body ECU) connector.

Measure the resistance according to the value(s) in the table below.
Standard Resistance:
Tester Connection
Switch Condition
Specified Condition
G63-9 (CANP) - G63-10 (CANN)
Engine switch off
108 to 132 Ω
Text in Illustration
*a
Front view of wire harness connector
(to Main Body ECU [Multiplex Network Body ECU])

REPAIR OR REPLACE CAN MAIN WIRE CONNECTED TO MAIN BODY ECU (CANP, CANN)

REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU) (LandCruiser RM000003WBO05FX.html)

7.CONNECT CONNECTOR

Reconnect the G133 No. 2 junction connector.

NEXT

8.CHECK FOR OPEN IN CAN BUS MAIN WIRE (NO. 5 JUNCTION CONNECTOR - NO. 2 JUNCTION CONNECTOR)

Disconnect the G103 No. 5 junction connector.

Measure the resistance according to the value(s) in the table below.
Standard Resistance:
Tester Connection
Switch Condition
Specified Condition
G103-3 (CANP) - G103-2 (CANN)
Engine switch off
108 to 132 Ω
Text in Illustration
*a
Rear view of wire harness connector
(to No. 5 Junction Connector)

REPAIR OR REPLACE CAN MAIN WIRE OR CONNECTOR (NO. 5 JUNCTION CONNECTOR - NO. 2 JUNCTION CONNECTOR)

REPLACE NO. 5 JUNCTION CONNECTOR

9.CHECK FOR SHORT IN CAN BUS WIRES (NO. 2 JUNCTION CONNECTOR - FRONT POWER SEAT SWITCH RH)

NOTICE:

For vehicles without a seat position memory, go to "Check for Short in CAN Bus Wires (No. 2 Junction Connector - Multiplex Tilt and Telescopic ECU)".

Disconnect the G133 No. 2 junction connector.

Measure the resistance according to the value(s) in the table below.

Standard Resistance:

Tester Connection	Switch Condition	Specified Condition
G133-2 (CANH) - G133-13 (CANL)	Engine switch off	200 Ω or higher
G133-2 (CANH) - G48-4 (CG)	Engine switch off	200 Ω or higher
G133-13 (CANL) - G48-4 (CG)	Engine switch off	200 Ω or higher
G133-2 (CANH) - G48-16 (BAT)	Engine switch off	6 kΩ or higher
G133-13 (CANL) - G48-16 (BAT)	Engine switch off	6 kΩ or higher

Text in Illustration
*a	Rear view of wire harness connector (to No. 2 Junction Connector)
*b	Front view of DLC3

Go to step 15

OK

10.CHECK FOR SHORT IN CAN BUS WIRES (NO. 2 JUNCTION CONNECTOR - MULTIPLEX TILT AND TELESCOPIC ECU)

NOTICE:

For vehicles without a power tilt and power telescopic steering column, go to "Check for Short in CAN Bus Wires (No. 2 Junction Connector - Driving Support Switch Control ECU)".

Measure the resistance according to the value(s) in the table below.

Standard Resistance:

Tester Connection	Switch Condition	Specified Condition
G133-3 (CANH) - G133-14 (CANL)	Engine switch off	200 Ω or higher
G133-3 (CANH) - G48-4 (CG)	Engine switch off	200 Ω or higher
G133-14 (CANL) - G48-4 (CG)	Engine switch off	200 Ω or higher
G133-3 (CANH) - G48-16 (BAT)	Engine switch off	6 kΩ or higher
G133-14 (CANL) - G48-16 (BAT)	Engine switch off	6 kΩ or higher

Text in Illustration
*a	Rear view of wire harness connector (to No. 2 Junction Connector)
*b	Front view of DLC3

Go to step 17

OK

11.CHECK FOR SHORT IN CAN BUS WIRES (NO. 2 JUNCTION CONNECTOR - DRIVING SUPPORT SWITCH CONTROL ECU)

NOTICE:

For vehicles without a multi-function switch, go to "Check for Short in CAN Bus Wires (No. 2 Junction Connector - Main Body ECU)".

Measure the resistance according to the value(s) in the table below.

Standard Resistance:

Tester Connection	Switch Condition	Specified Condition
G133-5 (CANH) - G133-16 (CANL)	Engine switch off	200 Ω or higher
G133-5 (CANH) - G48-4 (CG)	Engine switch off	200 Ω or higher
G133-16 (CANL) - G48-4 (CG)	Engine switch off	200 Ω or higher
G133-5 (CANH) - G48-16 (BAT)	Engine switch off	6 kΩ or higher
G133-16 (CANL) - G48-16 (BAT)	Engine switch off	6 kΩ or higher

Text in Illustration
*a	Rear view of wire harness connector (to No. 2 Junction Connector)
*b	Front view of DLC3

Go to step 19

OK

12.CHECK FOR SHORT IN CAN BUS WIRES (NO. 2 JUNCTION CONNECTOR - MAIN BODY ECU)

Measure the resistance according to the value(s) in the table below.

Standard Resistance:

Tester Connection	Switch Condition	Specified Condition
G133-4 (CANH) - G133-15 (CANL)	Engine switch off	108 to 132 Ω
G133-4 (CANH) - G48-4 (CG)	Engine switch off	200 Ω or higher
G133-15 (CANL) - G48-4 (CG)	Engine switch off	200 Ω or higher
G133-4 (CANH) - G48-16 (BAT)	Engine switch off	6 kΩ or higher
G133-15 (CANL) - G48-16 (BAT)	Engine switch off	6 kΩ or higher

Text in Illustration
*a	Rear view of wire harness connector (to No. 2 Junction Connector)
*b	Front view of DLC3

Go to step 21

OK

13.CHECK FOR SHORT IN CAN BUS WIRES (NO. 2 JUNCTION CONNECTOR - REAR TELEVISION CAMERA ASSEMBLY)

NOTICE:

For vehicles without a parking assist monitor system (for camera built-in ECU), go to "Check for Short in CAN Bus Wires (No. 2 Junction Connector - No. 5 Junction connector)".

Measure the resistance according to the value(s) in the table below.

Standard Resistance:

Tester Connection	Switch Condition	Specified Condition
G133-1 (CANH) - G133-12 (CANL)	Engine switch off	200 Ω or higher
G133-1 (CANH) - G48-4 (CG)	Engine switch off	200 Ω or higher
G133-12 (CANL) - G48-4 (CG)	Engine switch off	200 Ω or higher
G133-1 (CANH) - G48-16 (BAT)	Engine switch off	6 kΩ or higher
G133-12 (CANL) - G48-16 (BAT)	Engine switch off	6 kΩ or higher

Text in Illustration
*a	Rear view of wire harness connector (to No. 2 Junction Connector)
*b	Front view of DLC3

Go to step 23

OK

14.CHECK FOR SHORT IN CAN BUS WIRES (NO. 2 JUNCTION CONNECTOR - NO. 5 JUNCTION CONNECTOR)

Measure the resistance according to the value(s) in the table below.

Standard Resistance:

Tester Connection	Switch Condition	Specified Condition
G133-6 (CANH) - G133-17 (CANL)	Engine switch off	108 to 132 Ω
G133-6 (CANH) - G48-4 (CG)	Engine switch off	200 Ω or higher
G133-17 (CANL) - G48-4 (CG)	Engine switch off	200 Ω or higher
G133-6 (CANH) - G48-16 (BAT)	Engine switch off	6 kΩ or higher
G133-17 (CANL) - G48-16 (BAT)	Engine switch off	6 kΩ or higher

Text in Illustration
*a	Rear view of wire harness connector (to No. 2 Junction Connector)
*b	Front view of DLC3

Go to step 25

REPLACE NO. 2 JUNCTION CONNECTOR

15.CONNECT CONNECTOR

Reconnect the G133 No. 2 junction connector.

NEXT

16.CHECK FOR SHORT IN CAN BUS WIRES (FRONT POWER SEAT SWITCH RH)

Disconnect the a5 front power seat switch RH connector.

Measure the resistance according to the value(s) in the table below.

Standard Resistance:

Tester Connection	Switch Condition	Specified Condition
a5-8 (CANP) - a5-7 (CANN)	Engine switch off	54 to 69 Ω
a5-8 (CANP) - G48-4 (CG)	Engine switch off	200 Ω or higher
a5-7 (CANN) - G48-4 (CG)	Engine switch off	200 Ω or higher
a5-8 (CANP) - G48-16 (BAT)	Engine switch off	6 kΩ or higher
a5-7 (CANN) - G48-16 (BAT)	Engine switch off	6 kΩ or higher

Text in Illustration
*a	Rear view of wire harness connector (to Front Power Seat Switch RH)
*b	Front view of DLC3

REPAIR OR REPLACE CAN BRANCH WIRE CONNECTED TO FRONT POWER SEAT SWITCH RH (CANP, CANN)

REPLACE FRONT POWER SEAT SWITCH RH (LandCruiser RM000004673017X.html)

17.CONNECT CONNECTOR

Reconnect the G133 No. 2 junction connector.

NEXT

18.CHECK FOR SHORT IN CAN BUS WIRES (MULTIPLEX TILT AND TELESCOPIC ECU)

Disconnect the G116 multiplex tilt and telescopic ECU connector.

Measure the resistance according to the value(s) in the table below.

Standard Resistance:

Tester Connection	Switch Condition	Specified Condition
G116-5 (CANP) - G116-14 (CANN)	Engine switch off	54 to 69 Ω
G116-5 (CANP) - G48-4 (CG)	Engine switch off	200 Ω or higher
G116-14 (CANN) - G48-4 (CG)	Engine switch off	200 Ω or higher
G116-5 (CANP) - G48-16 (BAT)	Engine switch off	6 kΩ or higher
G116-14 (CANN) - G48-16 (BAT)	Engine switch off	6 kΩ or higher

Text in Illustration
*a	Rear view of wire harness connector (to Multiplex Tilt and Telescopic ECU)
*b	Front view of DLC3

REPAIR OR REPLACE CAN BRANCH WIRE CONNECTED TO MULTIPLEX TILT AND TELESCOPIC ECU (CANP, CANN)

REPLACE MULTIPLEX TILT AND TELESCOPIC ECU (LandCruiser RM0000039SD01GX.html)

19.CONNECT CONNECTOR

Reconnect the G133 No. 2 junction connector.

NEXT

20.CHECK FOR SHORT IN CAN BUS WIRES (DRIVING SUPPORT SWITCH CONTROL ECU)

for Automatic Transmission:

Disconnect the G163 driving support switch control ECU connector.

Measure the resistance according to the value(s) in the table below.

Standard Resistance:

Tester Connection	Switch Condition	Specified Condition
G163-2 (CANP) - G163-3 (CANN)	Engine switch off	54 to 69 Ω
G163-2 (CANP) - G48-4 (CG)	Engine switch off	200 Ω or higher
G163-3 (CANN) - G48-4 (CG)	Engine switch off	200 Ω or higher
G163-2 (CANP) - G48-16 (BAT)	Engine switch off	6 kΩ or higher
G163-3 (CANN) - G48-16 (BAT)	Engine switch off	6 kΩ or higher

Text in Illustration
*a	Front view of wire harness connector (to Driving Support Switch Control ECU)
*b	Front view of DLC3

for Manual Transmission:

Disconnect the G76 driving support switch control ECU connector.

Measure the resistance according to the value(s) in the table below.

Standard Resistance:

Tester Connection	Switch Condition	Specified Condition
G76-9 (CANP) - G76-10 (CANN)	Engine switch off	54 to 69 Ω
G76-9 (CANP) - G48-4 (CG)	Engine switch off	200 Ω or higher
G76-10 (CANN) - G48-4 (CG)	Engine switch off	200 Ω or higher
G76-9 (CANP) - G48-16 (BAT)	Engine switch off	6 kΩ or higher
G76-10 (CANN) - G48-16 (BAT)	Engine switch off	6 kΩ or higher

Text in Illustration
*a	Rear view of wire harness connector (to Driving Support Switch Control ECU)
*b	Front view of DLC3

REPAIR OR REPLACE CAN BRANCH WIRE CONNECTED TO DRIVING SUPPORT SWITCH CONTROL ECU (CANP, CANN)

REPLACE DRIVING SUPPORT SWITCH CONTROL ECU (LandCruiser RM00000466X024X.html)

21.CONNECT CONNECTOR

Reconnect the G133 No. 2 junction connector.

NEXT

22.CHECK FOR SHORT IN CAN BUS WIRES (MAIN BODY ECU)

Disconnect the G63 main body ECU (multiplex network body ECU) connector.

Measure the resistance according to the value(s) in the table below.

Standard Resistance:

Tester Connection	Switch Condition	Specified Condition
G63-9 (CANP) - G63-10 (CANN)	Engine switch off	108 to 132 Ω
G63-9 (CANP) - G48-4 (CG)	Engine switch off	200 Ω or higher
G63-10 (CANN) - G48-4 (CG)	Engine switch off	200 Ω or higher
G63-9 (CANP) - G48-16 (BAT)	Engine switch off	6 kΩ or higher
G63-10 (CANN) - G48-16 (BAT)	Engine switch off	6 kΩ or higher

Text in Illustration
*a	Front view of wire harness connector (to Main Body ECU [Multiplex Network Body ECU])
*b	Front view of DLC3

REPAIR OR REPLACE CAN MAIN WIRE CONNECTED TO MAIN BODY ECU (CANP, CANN)

REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU) (LandCruiser RM000003WBO05FX.html)

23.CONNECT CONNECTOR

Reconnect the G133 No. 2 junction connector.

NEXT

24.CHECK FOR SHORT IN CAN BUS WIRES (REAR TELEVISION CAMERA ASSEMBLY)

Disconnect the v3*1 or X10*2 rear television camera assembly connector.
1. *1: w/ Tire Carrier
2. *2: w/o Tire Carrier

Measure the resistance according to the value(s) in the table below.

Standard Resistance:

w/ Tire Carrier
Tester Connection	Switch Condition	Specified Condition
v3-4 (CANH) - v3-1 (CANL)	Engine switch off	54 to 69 Ω
v3-4 (CANH) - G48-4 (CG)	Engine switch off	200 Ω or higher
v3-1 (CANL) - G48-4 (CG)	Engine switch off	200 Ω or higher
v3-4 (CANH) - G48-16 (BAT)	Engine switch off	6 kΩ or higher
v3-1 (CANL) - G48-16 (BAT)	Engine switch off	6 kΩ or higher

w/o Tire Carrier
Tester Connection	Switch Condition	Specified Condition
X10-4 (H) - X10-1 (L)	Engine switch off	54 to 69 Ω
X10-4 (H) - G48-4 (CG)	Engine switch off	200 Ω or higher
X10-1 (L) - G48-4 (CG)	Engine switch off	200 Ω or higher
X10-4 (H) - G48-16 (BAT)	Engine switch off	6 kΩ or higher
X10-1 (L) - G48-16 (BAT)	Engine switch off	6 kΩ or higher

Text in Illustration
*A	w/ Tire Carrier
*B	w/o Tire Carrier
*a	Front view of wire harness connector (to Rear Television Camera Assembly)
*b	Front view of DLC3

Result
Result	Proceed to
OK (w/ Tire Carrier)	A
OK (w/o Tire Carrier)	B
NG (w/ Tire Carrier)	C
NG (w/o Tire Carrier)	D

REPLACE REAR TELEVISION CAMERA ASSEMBLY (LandCruiser RM00000470U00MX.html)

REPAIR OR REPLACE CAN BRANCH WIRE CONNECTED TO REAR TELEVISION CAMERA ASSEMBLY (CANH, CANL)

REPAIR OR REPLACE CAN BRANCH WIRE CONNECTED TO REAR TELEVISION CAMERA ASSEMBLY (H, L)

REPLACE REAR TELEVISION CAMERA ASSEMBLY (LandCruiser RM00000470R008X.html)

25.CONNECT CONNECTOR

Reconnect the G133 No. 2 junction connector.

NEXT

26.CHECK FOR SHORT IN CAN BUS WIRES (NO. 5 JUNCTION CONNECTOR)

Disconnect the G103 No. 5 junction connector.

Measure the resistance according to the value(s) in the table below.

Standard Resistance:

Tester Connection	Switch Condition	Specified Condition
G103-3 (CANP) - G103-2 (CANN)	Engine switch off	108 to 132 Ω
G103-3 (CANP) - G48-4 (CG)	Engine switch off	200 Ω or higher
G103-2 (CANN) - G48-4 (CG)	Engine switch off	200 Ω or higher
G103-3 (CANP) - G48-16 (BAT)	Engine switch off	6 kΩ or higher
G103-2 (CANN) - G48-16 (BAT)	Engine switch off	6 kΩ or higher

Text in Illustration
*a	Rear view of wire harness connector (to No. 5 Junction Connector)
*b	Front view of DLC3

REPAIR OR REPLACE CAN MAIN WIRE OR CONNECTOR (NO. 5 JUNCTION CONNECTOR - NO. 2 JUNCTION CONNECTOR)

REPLACE NO. 5 JUNCTION CONNECTOR

27.CHECK HARNESS AND CONNECTOR (MAIN BODY ECU - BATTERY AND BODY GROUND)

Connect the cable to the negative (-) battery terminal.

Text in Illustration
*a
Rear view of wire harness connector
(to Main Body ECU [Multiplex Network Body ECU])
*b
Front view of wire harness connector
(to Main Body ECU [Multiplex Network Body ECU])
NOTICE:
When disconnecting the cable, some systems need to be initialized after the cable is reconnected (LandCruiser RM000003YMD00TX.html).

Remove the main body ECU (multiplex network body ECU) (LandCruiser RM000003WBO05FX.html).

Measure the resistance according to the value(s) in the table below.
Standard Resistance:
Tester Connection
Condition
Specified Condition
G63-3 (GND2) - Body ground
Always
Below 1 Ω
A-11 (GND1) - Body ground
Always
Below 1 Ω

Measure the voltage according to the value(s) in the table below.

Standard Voltage:

Tester Connection	Condition	Specified Condition
A-30 (BECU) - Body ground	Always	11 to 14 V
A-31 (ALTB) - Body ground	Always	11 to 14 V
A-29 (ACC) - Body ground	Engine switch on (ACC)	11 to 14 V
A-32 (IG) - Body ground	Engine switch on (IG)	11 to 14 V

REPAIR OR REPLACE HARNESS OR CONNECTOR

REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU) (LandCruiser RM000003WBO05FX.html)