Short in CAN Bus Lines

CAN COMMUNICATION: CAN COMMUNICATION SYSTEM: Short in CAN Bus Lines

Short in CAN Bus Lines

DESCRIPTION

There may be a short circuit between the CAN bus lines when the resistance between terminals 6 (CANH) and 14 (CANL) of the DLC3 is below 54 Ohms.






WIRING DIAGRAM









INSPECTION PROCEDURE
NOTICE:
- Turn the ignition switch OFF before measuring the resistances of the main wire and the branch wire.
- After the ignition switch is turned OFF, check that the key reminder warning system and light reminder warning system are not in operation.
- Before measuring the resistance, leave the vehicle for at least 1 minute and do not operate the ignition switch, any switches or doors. If doors need to be opened in order to check connectors, open the doors and leave them open.
HINT: Operating the ignition switch, any switches or any doors triggers related ECU and sensor communication with the CAN, which causes resistance variation.

PROCEDURE

1. CHECK CAN BUS LINES FOR SHORT CIRCUIT (DLC3 BRANCH WIRE)





(a) Disconnect the E68 No. 2 junction connector.
(b) Measure the resistance of the DLC3.
Standard resistance:






NG -- REPAIR OR REPLACE DLC3 BRANCH WIRE AND CONNECTOR (CANH, CANL)
OK -- Continue to next step.
2. CONNECT CONNECTOR
(a) Reconnect the E68 No. 2 junction connector.
NEXT -- Continue to next step.
3. CHECK CAN BUS LINES FOR SHORT CIRCUIT (NO. 1 JUNCTION CONNECTOR SIDE)





(a) Disconnect the A36 No. 1 junction connector.
(b) Measure the resistance of the DLC3.
Standard resistance:






OK -- CHECK CAN BUS LINES FOR SHORT CIRCUIT (NO. 1 JUNCTION CONNECTOR - ECM)
NG -- Continue to next step.
4. CHECK CAN BUS LINES FOR SHORT CIRCUIT (NO. 1 JUNCTION CONNECTOR - NO. 2 JUNCTION CONNECTOR)





(a) Disconnect the E68 No. 2 junction connector.
(b) Measure the resistance of the wire harness side connector.
Standard resistance:






NG -- REPAIR OR REPLACE CAN MAIN WIRE AND CONNECTOR (NO. 1 JUNCTION CONNECTOR - NO. 2 JUNCTION CONNECTOR)
OK -- Continue to next step.
5. CONNECT CONNECTOR
(a) Reconnect the A36 No. 1 junction connector.
(b) Reconnect the E68 No. 2 junction connector.
NEXT -- Continue to next step.
6. CHECK CAN BUS LINES FOR SHORT CIRCUIT (NO. 3 JUNCTION CONNECTOR, NO. 4 JUNCTION CONNECTOR SIDE)





(a) Disconnect the E70 No. 3 junction connector.
(b) Measure the resistance of the DLC3.
Standard resistance:






NG -- CONNECT CONNECTOR
OK -- Continue to next step.
7. CONNECT CONNECTOR
(a) Reconnect the E70 No. 3 junction connector.
NEXT -- Continue to next step.
8. CHECK CAN BUS LINES FOR SHORT CIRCUIT (NO. 4 JUNCTION CONNECTOR SIDE)





(a) Disconnect the E69 No. 4 junction connector.
(b) Measure the resistance of the DLC3.
Standard resistance:






OK -- CHECK CAN BUS LINES FOR SHORT CIRCUIT (NO. 4 JUNCTION CONNECTOR - 4WD CONTROL ECU)
NG -- Continue to next step.
9. CHECK CAN BUS LINES FOR SHORT CIRCUIT (NO. 3 JUNCTION CONNECTOR - NO. 4 JUNCTION CONNECTOR)





(a) Disconnect the E70 No. 3 junction connector.
(b) Measure the resistance of the wire harness side connector.
Standard resistance:






NG -- REPAIR OR REPLACE CAN MAIN WIRE AND CONNECTOR (NO. 3 JUNCTION CONNECTOR - NO. 4 JUNCTION CONNECTOR)
OK -- Continue to next step.
10. CONNECT CONNECTOR
(a) Reconnect the E69 No. 4 junction connector.
NEXT -- Continue to next step.
11. CHECK CAN BUS LINES FOR SHORT CIRCUIT (NO. 3 JUNCTION CONNECTOR - CENTER AIRBAG SENSOR ASSEMBLY)





(a) Measure the resistance of the wire harness side connector.
Result:






B -- REPAIR OR REPLACE NO. 3 JUNCTION CONNECTOR
A -- Continue to next step.
12. CONNECT CONNECTOR
(a) Reconnect the E70 No. 3 junction connector.
NEXT -- Continue to next step.
13. CHECK CAN BUS LINES FOR SHORT CIRCUIT (CENTER AIRBAG SENSOR ASSEMBLY)





(a) Disconnect the E45 center airbag sensor connector.
(b) Measure the resistance of the DLC3.
Standard resistance:






NG -- REPAIR OR REPLACE CAN BRANCH WIRE CONNECTED TO CENTER AIRBAG SENSOR ASSEMBLY (CANH, CANL)
OK -- REPLACE CENTER AIRBAG SENSOR ASSEMBLY
14. CHECK CAN BUS LINES FOR SHORT CIRCUIT (NO. 1 JUNCTION CONNECTOR - ECM)





(a) Measure the resistance of the wire harness side connector.
Result:






A -- CONNECT CONNECTOR
B -- Continue to next step.
15. CHECK CAN BUS LINES FOR SHORT CIRCUIT (NO. 1 JUNCTION CONNECTOR - ABS AND TRACTION ACTUATOR)





(a) Measure the resistance of the wire harness side connector.
Result:






A -- CONNECT CONNECTOR
B -- REPAIR OR REPLACE NO. 1 JUNCTION CONNECTOR
16. CONNECT CONNECTOR
(a) Reconnect the A36 No. 1 junction connector.
NEXT -- Continue to next step.
17. CHECK CAN BUS LINES FOR SHORT CIRCUIT (ECM)





(a) Disconnect the A9 ECM connector.
(b) Measure the resistance of the DLC3.
Standard resistance:






NG -- REPAIR OR REPLACE CAN MAIN WIRE CONNECTED TO ECM (NO. 1 JUNCTION CONNECTOR - ECM)
OK -- REPLACE ECM
18. CONNECT CONNECTOR
(a) Reconnect the A36 No. 1 junction connector.
NEXT -- Continue to next step.
19. CHECK CAN BUS LINES FOR SHORT CIRCUIT (ABS AND TRACTION ACTUATOR)





(a) Disconnect the A19 ABS and brake actuator (skid control ECU) connector.
(b) Measure the resistance of the DLC3.
Standard resistance:






NG -- REPAIR OR REPLACE CAN BRANCH WIRE CONNECTED TO ABS AND TRACTION ACTUATOR (CANH, CANL)
OK -- REPLACE ABS AND TRACTION ACTUATOR (SKID CONTROL ECU)
20. CONNECT CONNECTOR
(a) Reconnect the E70 No. 3 junction connector.
NEXT -- Continue to next step.
21. CHECK CAN BUS LINES FOR SHORT CIRCUIT (NO. 2 JUNCTION CONNECTOR - YAW RATE SENSOR)





(a) Disconnect the E68 No. 2 junction connector.
(b) Measure the resistance of the wire harness side connector.
Result:






A -- CONNECT CONNECTOR
B -- Continue to next step.
22. CHECK CAN BUS LINES FOR SHORT CIRCUIT (NO. 2 JUNCTION CONNECTOR - POWER STEERING ECU)





(a) Measure the resistance of the wire harness side connector.
Result:






A -- CONNECT CONNECTOR
B -- Continue to next step.
23. CHECK CAN BUS LINES FOR SHORT CIRCUIT (NO. 2 JUNCTION CONNECTOR - MAIN BODY ECU)





(a) Measure the resistance of the wire harness side connector.
Result:






A -- CONNECT CONNECTOR
B -- Continue to next step.
24. CHECK CAN BUS LINES FOR SHORT CIRCUIT (NO. 2 JUNCTION CONNECTOR - AIR CONDITIONING AMPLIFIER)





(a) Measure the resistance of the wire harness side connector.
Result:






A -- CONNECT CONNECTOR
B -- Continue to next step.
25. CHECK CAN BUS LINES FOR SHORT CIRCUIT (NO. 2 JUNCTION CONNECTOR - STEERING ANGLE SENSOR)





(a) Measure the resistance of the wire harness side connector.
Result:






A -- CONNECT CONNECTOR
B -- REPAIR OR REPLACE NO. 2 JUNCTION CONNECTOR
26. CONNECT CONNECTOR
(a) Reconnect the E68 No. 2 junction connector.
NEXT -- Continue to next step.
27. CHECK CAN BUS LINES FOR SHORT CIRCUIT (YAW RATE SENSOR)





(a) Disconnect the K6 yaw rate sensor connector.
(b) Measure the resistance of the DLC3.
Standard resistance:






NG -- REPAIR OR REPLACE CAN BRANCH WIRE CONNECTED TO YAW RATE SENSOR (CANH, CANL)
OK -- REPLACE YAW RATE SENSOR
28. CONNECT CONNECTOR
(a) Reconnect the E68 No. 2 junction connector.
NEXT -- Continue to next step.
29. CHECK CAN BUS LINES FOR SHORT CIRCUIT (POWER STEERING ECU)





(a) Disconnect the E18 power steering ECU connector.
(b) Measure the resistance of the DLC3.
Standard resistance:






NG -- REPAIR OR REPLACE CAN BRANCH WIRE CONNECTED TO POWER STEERING ECU (CANH, CANL)
OK -- REPLACE POWER STEERING ECU
30. CONNECT CONNECTOR
(a) Reconnect the E68 No. 2 junction connector.
NEXT -- Continue to next step.
31. CHECK CAN BUS LINES FOR SHORT CIRCUIT (MAIN BODY ECU)





(a) Disconnect the E17 main body ECU connector.
(b) Measure the resistance of the DLC3.
Standard resistance:






NG -- REPAIR OR REPLACE CAN BRANCH WIRE CONNECTED TO MAIN BODY ECU (CANH, CANL)
OK -- REPLACE INSTRUMENT PANEL JUNCTION BLOCK (MAIN BODY ECU)
32. CONNECT CONNECTOR
(a) Reconnect the E68 No. 2 junction connector.
NEXT -- Continue to next step.
33. CHECK CAN BUS LINES FOR SHORT CIRCUIT (AIR CONDITIONING AMPLIFIER)





(a) Disconnect the E37*1 or E36*2 air conditioning amplifier connector.
- *1: for Automatic air conditioning system.
- *2: for Manual air conditioning system.
(b) Measure the resistance of the DLC3.
Standard resistance:






NG -- REPAIR OR REPLACE CAN BRANCH WIRE CONNECTED TO AIR CONDITIONING AMPLIFIER (CANH, CANL)
OK -- REPLACE AIR CONDITIONING AMPLIFIER
34. CONNECT CONNECTOR
(a) Reconnect the E68 No. 2 junction connector.
NEXT -- Continue to next step.
35. CHECK CAN BUS LINES FOR SHORT CIRCUIT (STEERING ANGLE SENSOR)





(a) Disconnect the E11 steering sensor connector.
(b) Measure the resistance of the DLC3.
Standard resistance:






NG -- REPAIR OR REPLACE CAN BRANCH WIRE CONNECTED TO STEERING ANGLE SENSOR (CANH, CANL)
OK -- REPLACE STEERING ANGLE SENSOR
36. CHECK CAN BUS LINES FOR SHORT CIRCUIT (NO. 4 JUNCTION CONNECTOR - 4WD CONTROL ECU)
NOTE: For vehicles without 4WD, go to "CHECK CAN BUS LINES FOR SHORT CIRCUIT (NO. 4 JUNCTION CONNECTOR - COMBINATION METER ECU)".





(a) Measure the resistance of the wire harness side connector.
Result:






A -- CONNECT CONNECTOR
B -- Continue to next step.
37. CHECK CAN BUS LINES FOR SHORT CIRCUIT (NO. 4 JUNCTION CONNECTOR - COMBINATION METER ECU)





(a) Measure the resistance of the wire harness side connector.
Result:






A -- CONNECT CONNECTOR
B -- REPAIR OR REPLACE NO. 4 JUNCTION CONNECTOR
38. CONNECT CONNECTOR
(a) Reconnect the E69 No. 4 junction connector.
NEXT -- Continue to next step.
39. CHECK CAN BUS LINES FOR SHORT CIRCUIT (4WD CONTROL ECU)





(a) Disconnect the E57 4WD control ECU connector.
(b) Measure the resistance of the DLC3.
Standard resistance:






NG -- REPAIR OR REPLACE CAN BRANCH WIRE CONNECTED TO 4WD CONTROL ECU (CANH, CANL)
OK -- REPLACE 4WD CONTROL ECU
40. CONNECT CONNECTOR
(a) Reconnect the E69 No. 4 junction connector.
NEXT -- Continue to next step.
41. CHECK CAN BUS LINES FOR SHORT CIRCUIT (COMBINATION METER ECU)





(a) Disconnect the E19 combination meter ECU connector.
(b) Measure the resistance of the DLC3.
Standard resistance:






NG -- REPAIR OR REPLACE CAN MAIN WIRE CONNECTED TO COMBINATION METER ECU (CANH, CANL)
OK -- REPLACE COMBINATION METER ECU