Part 1

CAN COMMUNICATION: CAN COMMUNICATION SYSTEM: U1004: Lost Communication with Engine Gateway Module
U1004 - Lost Communication with Engine Gateway Module

DESCRIPTION

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 [branch wire]/CANL [branch wire] of the ECU and/or sensor is open.)





HINT
*1: w/ Dynamic Radar Cruise Control System or Pre-collision System

*2: w/ Active Stabilizer Suspension System

WIRING DIAGRAM









INSPECTION PROCEDURE

PROCEDURE

1. DISCONNECT CABLE FROM NEGATIVE BATTERY TERMINAL

(a) Disconnect the cable from the negative (-) battery terminal before measuring the resistances of the main wire and the branch wire.

CAUTION:
Wait at least 90 seconds after disconnecting the cable from the negative (-) battery terminal to prevent airbag and seat belt pretensioner activation.

NOTICE:
* w/ Navigation System (for HDD):
After the power switch is turned off, the display and navigation module display (HDD navigation system) records various types of memory and settings. As a result, after turning the power switch off, be sure to wait for the time specified in the table before disconnecting the cable from the negative (-) battery terminal.

Waiting Time before Disconnecting Cable from Negative (-) Battery Terminal:





* When disconnecting the cable, some systems need to be initialized after the cable is reconnected Repair Instruction - Initialization.

NEXT -- Continue to next step.

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

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





Standard resistance:





Result





C -- CHECK HARNESS AND CONNECTOR (ECM - BATTERY AND BODY GROUND)

B -- CHECK FOR SHORT IN CAN BUS WIRES (NO. 7 JUNCTION CONNECTOR SIDE)
A -- Continue to next step.

3. CHECK FOR OPEN IN CAN BUS MAIN WIRE (NO. 7 JUNCTION CONNECTOR - ELECTRIC PARKING BRAKE ECU)

(a) Disconnect the A66 No. 7 junction connector connector.





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

Standard resistance:





NG -- CONNECT CONNECTOR
OK -- Continue to next step.

4. CHECK FOR OPEN IN CAN BUS MAIN WIRE (NO. 7 JUNCTION CONNECTOR - POWER STEERING ECU)

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





Standard resistance:





NG -- CONNECT CONNECTOR

OK -- REPLACE NO. 7 JUNCTION CONNECTOR

5. CONNECT CONNECTOR

(a) Reconnect the A66 No. 7 junction connector connector.

NEXT -- Continue to next step.

6. CHECK FOR OPEN IN CAN BUS MAIN WIRE (POWER STEERING ECU - NO. 7 JUNCTION CONNECTOR)

(a) Disconnect the A44 power steering ECU connector.





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

Standard resistance:





NG -- REPAIR OR REPLACE CAN MAIN WIRE CONNECTED TO POWER STEERING ECU (POWER STEERING ECU - NO. 7 JUNCTION CONNECTOR)

OK -- REPLACE POWER STEERING ECU Removal

7. CONNECT CONNECTOR

(a) Reconnect the A66 No. 7 junction connector connector.

NEXT -- Continue to next step.

8. CHECK FOR OPEN IN CAN BUS MAIN WIRE (NO. 6 JUNCTION CONNECTOR - NO. 7 JUNCTION CONNECTOR)

(a) Disconnect the A86 No. 6 junction connector connector.





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

Standard resistance:





NG -- REPAIR OR REPLACE CAN MAIN WIRE OR CONNECTOR (NO. 6 JUNCTION CONNECTOR - NO. 7 JUNCTION CONNECTOR)
OK -- Continue to next step.

9. CHECK FOR OPEN IN CAN BUS MAIN WIRE (NO. 6 JUNCTION CONNECTOR - ELECTRIC PARKING BRAKE ECU)

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





Standard resistance:





NG -- CONNECT CONNECTOR

OK -- REPLACE NO. 6 JUNCTION CONNECTOR

10. CONNECT CONNECTOR

(a) Reconnect the A86 No. 6 junction connector connector.

NEXT -- Continue to next step.

11. CHECK FOR OPEN IN CAN BUS MAIN WIRE (NO. 4 JUNCTION CONNECTOR - NO. 6 JUNCTION CONNECTOR)





(a) Disconnect the S73 No. 4 junction connector connector.

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

Standard resistance:





NG -- REPAIR OR REPLACE CAN MAIN WIRE OR CONNECTOR (NO. 4 JUNCTION CONNECTOR - NO. 6 JUNCTION CONNECTOR)
OK -- Continue to next step.

12. CHECK FOR OPEN IN CAN BUS MAIN WIRE (NO. 4 JUNCTION CONNECTOR - ELECTRIC PARKING BRAKE ECU)





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

Standard resistance:





NG -- CONNECT CONNECTOR

OK -- REPLACE NO. 4 JUNCTION CONNECTOR

13. CONNECT CONNECTOR

(a) Reconnect the S73 No. 4 junction connector connector.

NEXT -- Continue to next step.

14. CHECK FOR OPEN IN CAN BUS MAIN WIRE (ELECTRIC PARKING BRAKE ECU - NO. 4 JUNCTION CONNECTOR)

(a) Disconnect the S48 electric parking brake ECU connector.





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

Standard resistance:





NG -- REPAIR OR REPLACE CAN MAIN WIRE CONNECTED TO ELECTRIC PARKING BRAKE ECU (ELECTRIC PARKING BRAKE ECU - NO. 4 JUNCTION CONNECTOR)

OK -- REPLACE ELECTRIC PARKING BRAKE ECU Removal

15. CHECK FOR SHORT IN CAN BUS WIRES (NO. 7 JUNCTION CONNECTOR SIDE)

(a) Disconnect the A66 No. 7 junction connector connector.





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

Standard resistance:





NG -- CONNECT CONNECTOR
OK -- Continue to next step.

16. CHECK FOR SHORT IN CAN BUS WIRES (NO. 7 JUNCTION CONNECTOR - SUSPENSION CONTROL ECU)

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





Result





NG -- CONNECT CONNECTOR
OK -- Continue to next step.

17. CHECK FOR SHORT IN CAN BUS WIRES (NO. 7 JUNCTION CONNECTOR - STEERING CONTROL ECU)

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





Result





NG -- CONNECT CONNECTOR
OK -- Continue to next step.

18. CHECK FOR SHORT IN CAN BUS WIRES (NO. 7 JUNCTION CONNECTOR - PARKING ASSIST ECU)

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





Result





NG -- CONNECT CONNECTOR
OK -- Continue to next step.

19. CHECK FOR SHORT IN CAN BUS WIRES (NO. 7 JUNCTION CONNECTOR - POWER STEERING ECU)

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





Result





NG -- CONNECT CONNECTOR

OK -- REPAIR OR REPLACE NO. 7 JUNCTION CONNECTOR

20. CONNECT CONNECTOR

(a) Reconnect the A66 No. 7 junction connector connector.

NEXT -- Continue to next step.

21. CHECK FOR SHORT IN CAN BUS WIRES (SUSPENSION CONTROL ECU)

(a) Reconnect the R1 suspension control ECU connector.





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

Result





NG -- REPAIR OR REPLACE CAN BRANCH WIRE CONNECTED TO SUSPENSION CONTROL ECU (CA2H, CA2L)

OK -- REPLACE SUSPENSION CONTROL ECU Removal

22. CONNECT CONNECTOR

(a) Reconnect the A66 No. 7 junction connector connector.

NEXT -- Continue to next step.

23. CHECK FOR SHORT IN CAN BUS WIRES (STEERING CONTROL ECU)

(a) Disconnect the A42 steering control ECU connector.





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

Result





NG -- REPAIR OR REPLACE CAN BRANCH WIRE CONNECTED TO STEERING CONTROL ECU (CAN+, CAN-)

OK -- REPLACE STEERING CONTROL ECU Removal

24. CONNECT CONNECTOR

(a) Reconnect the A66 No. 7 junction connector connector.

NEXT -- Continue to next step.

25. CHECK FOR SHORT IN CAN BUS WIRES (PARKING ASSIST ECU)

(a) Disconnect the L90 parking assist ECU connector.





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

Result





NG -- REPAIR OR REPLACE CAN BRANCH WIRE CONNECTED TO PARKING ASSIST ECU (CA2H, CA2L)

OK -- REPLACE PARKING ASSIST ECU Removal

26. CONNECT CONNECTOR

(a) Reconnect the A66 No. 7 junction connector connector.

NEXT -- Continue to next step.

27. CHECK FOR SHORT IN CAN BUS WIRES (POWER STEERING ECU)

(a) Disconnect the A44 power steering ECU connector.





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

Result





NG -- REPAIR OR REPLACE CAN MAIN WIRE CONNECTED TO POWER STEERING ECU (NO. 7 JUNCTION CONNECTOR - POWER STEERING ECU)

OK -- REPLACE POWER STEERING ECU Removal