Short in CAN Bus Lines

NETWORKING: 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.





HINT:
- *1: w/ Bus buffer ECU
- *2: w/ 4WD
- *3: w/ Air suspension system
- *4: w/ Dynamic laser cruise control system

WIRING DIAGRAM









INSPECTION PROCEDURE

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

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 disable the SRS system.

NEXT -- Continue to next step.

2. CHECK FOR SHORT IN CAN BUS WIRES (DLC3 BRANCH WIRE)





(a) Disconnect the H93 No. 1 junction connector.
(b) Measure the resistance according to the value(s) in the table below.

Standard Resistance:





NG -- REPAIR OR REPLACE CAN BRANCH WIRE CONNECTED TO DLC3 (CANH, CANL)
OK -- Continue to next step.

3. CONNECT CONNECTOR
(a) Reconnect the H93 No. 1 junction connector.
NEXT -- Continue to next step.

4. CHECK FOR SHORT IN CAN BUS WIRES (NO. 2 JUNCTION CONNECTOR SIDE)





(a) Disconnect the H100 No. 2 junction connector.
(b) Measure the resistance according to the value(s) in the table below.

Standard Resistance:





NG -- CHECK FOR SHORT IN CAN BUS WIRES (NO. 1 JUNCTION CONNECTOR - NO. 2 JUNCTION CONNECTOR)
OK -- Continue to next step.

5. CONNECT CONNECTOR
(a) Reconnect the H100 No. 2 junction connector.
NEXT -- Continue to next step.

6. CHECK FOR SHORT IN CAN BUS WIRES (NO. 2 JUNCTION CONNECTOR - AIR CONDITIONING AMPLIFIER)





(a) Disconnect the H92 No. 2 junction connector.
(b) Measure the resistance according to the value(s) in the table below.

Standard Resistance:





NG -- CHECK FOR SHORT IN CAN BUS WIRES (AIR CONDITIONING AMPLIFIER)
OK -- Continue to next step.

7. CHECK FOR SHORT IN CAN BUS WIRES (NO. 2 JUNCTION CONNECTOR - BUS BUFFER ECU)

NOTE: For vehicles without bus buffer ECU, go to "Check for Short in CAN Bus Wires (No. 2 Junction Connector - 4WD Control ECU)".





(a) Disconnect the H105 No. 2 junction connector.
(b) Measure the resistance according to the value(s) in the table below.

Standard Resistance:





NG -- CHECK FOR SHORT IN CAN BUS WIRES (BUS BUFFER ECU)
OK -- Continue to next step.

8. CHECK FOR SHORT IN CAN BUS WIRES (NO. 2 JUNCTION CONNECTOR - 4WD CONTROL ECU)

NOTE: For vehicles without 4WD, go to "Check for Short in CAN Bus Wires (No. 2 Junction Connector - ECM)".





(a) Disconnect the H95 No. 2 junction connector.
(b) Measure the resistance according to the value(s) in the table below.

Standard Resistance:





NG -- CHECK FOR SHORT IN CAN BUS WIRES (4WD CONTROL ECU)
OK -- Continue to next step.

9. CHECK FOR SHORT IN CAN BUS WIRES (NO. 2 JUNCTION CONNECTOR - ECM)





(a) Disconnect the H99 No. 2 junction connector.
(b) Measure the resistance according to the value(s) in the table below.

Standard Resistance:





NG -- CHECK FOR SHORT IN CAN BUS WIRES (ECM)
OK -- REPAIR OR REPLACE NO. 2 JUNCTION CONNECTOR
10. CHECK FOR SHORT IN CAN BUS WIRES (AIR CONDITIONING AMPLIFIER)





(a) Disconnect the H24 air conditioning amplifier connector.
(b) Measure the resistance according to the value(s) in the table below.

Standard Resistance:





NG -- REPAIR OR REPLACE CAN BRANCH WIRE CONNECTED TO AIR CONDITIONING AMPLIFIER (CANH, CANL)
OK -- REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY
11. CHECK FOR SHORT IN CAN BUS WIRES (BUS BUFFER ECU)





(a) Disconnect the H66 bus buffer ECU connector.
(b) Measure the resistance according to the value(s) in the table below.

Standard Resistance:





NG -- REPAIR OR REPLACE CAN BRANCH WIRE CONNECTED TO BUS BUFFER ECU (CANH, CANL)
OK -- REPLACE BUS BUFFER ECU
12. CHECK FOR SHORT IN CAN BUS WIRES (4WD CONTROL ECU)





(a) Disconnect the A28 4WD control ECU connector.
(b) Measure the resistance according to the value(s) in the table below.

Standard Resistance:





NG -- REPAIR OR REPLACE CAN BRANCH WIRE CONNECTED TO 4WD CONTROL ECU (CANH, CANL)
OK -- REPLACE 4WD CONTROL ECU
13. CHECK FOR SHORT IN CAN BUS WIRES (ECM)





(a) Disconnect the A27 ECM connector.
(b) Measure the resistance according to the value(s) in the table below.

Standard Resistance:





Result





D -- REPLACE ECM
C -- REPLACE ECM
B -- REPLACE ECM
A -- REPAIR OR REPLACE CAN MAIN WIRE CONNECTED TO ECM (CANH, CANL)
14. CHECK FOR SHORT IN CAN BUS WIRES (NO. 1 JUNCTION CONNECTOR - NO. 2 JUNCTION CONNECTOR)





(a) Disconnect the H101 No. 1 junction 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. 1 JUNCTION CONNECTOR - NO. 2 JUNCTION CONNECTOR)
OK -- Continue to next step.

15. CONNECT CONNECTOR
(a) Reconnect the H101 No. 1 junction connector.
(b) Reconnect the H100 No. 2 junction connector.
NEXT -- Continue to next step.

16. CHECK FOR SHORT IN CAN BUS WIRES (NO. 4 JUNCTION CONNECTOR SIDE)

NOTE: For vehicles without air suspension system, go to "Check for Short in CAN Bus Wires (No. 1 Junction Connector - Combination Meter ECU)".





(a) Disconnect the O41 No. 4 junction connector.
(b) Measure the resistance according to the value(s) in the table below.

Standard Resistance:





NG -- CHECK FOR SHORT IN CAN BUS WIRES (NO. 1 JUNCTION CONNECTOR - NO. 4 JUNCTION CONNECTOR)
OK -- Continue to next step.

17. CONNECT CONNECTOR
(a) Reconnect the O41 No. 4 junction connector.
NEXT -- Continue to next step.

18. CHECK FOR SHORT IN CAN BUS WIRES (NO. 4 JUNCTION CONNECTOR - SUSPENSION CONTROL ECU)





(a) Disconnect the O42 No. 4 junction connector.
(b) Measure the resistance according to the value(s) in the table below.

Standard Resistance:





NG -- CHECK FOR SHORT IN CAN BUS WIRES (SUSPENSION CONTROL ECU)
OK -- Continue to next step.

19. CHECK FOR SHORT IN CAN BUS WIRES (NO. 4 JUNCTION CONNECTOR - COMBINATION METER ECU)





(a) Disconnect the O41 No. 4 junction connector.
(b) Measure the resistance according to the value(s) in the table below.

Standard Resistance:





NG -- CHECK FOR SHORT IN CAN BUS WIRES (COMBINATION METER ECU)
OK -- REPAIR OR REPLACE NO. 4 JUNCTION CONNECTOR
20. CHECK FOR SHORT IN CAN BUS WIRES (NO. 1 JUNCTION CONNECTOR - NO. 4 JUNCTION CONNECTOR)





(a) Disconnect the H91 No. 1 junction 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. 1 JUNCTION CONNECTOR - NO. 4 JUNCTION CONNECTOR)
OK -- Continue to next step.

21. CHECK FOR SHORT IN CAN BUS WIRES (NO. 1 JUNCTION CONNECTOR - COMBINATION METER ECU)

NOTE: For vehicles without air suspension system, go to "Check for Short in CAN Bus Wires (No. 1 Junction Connector - Power Steering ECU)".





(a) Disconnect the H91 No. 1 junction connector.
(b) Measure the resistance according to the value(s) in the table below.

Standard Resistance:





NG -- CHECK FOR SHORT IN CAN BUS WIRES (COMBINATION METER ECU)
OK -- Continue to next step.

22. CHECK FOR SHORT IN CAN BUS WIRES (NO. 1 JUNCTION CONNECTOR - POWER STEERING ECU)





(a) Disconnect the H106 No. 1 junction connector.
(b) Measure the resistance according to the value(s) in the table below.

Standard Resistance:





NG -- CHECK FOR SHORT IN CAN BUS WIRES (POWER STEERING ECU)
OK -- Continue to next step.

23. CHECK FOR SHORT IN CAN BUS WIRES (NO. 1 JUNCTION CONNECTOR - DISTANCE CONTROL ECU)

NOTE: For vehicles with air suspension system, go to "Check for Short in CAN Bus Wires (No. 1 Junction Connector - Main Body ECU)".





(a) Disconnect the A60 No. 1 junction connector.
(b) Measure the resistance according to the value(s) in the table below.

Standard Resistance:





NG -- CHECK FOR SHORT IN CAN BUS WIRES (DISTANCE CONTROL ECU)
OK -- Continue to next step.

24. CHECK FOR SHORT IN CAN BUS WIRES (NO. 1 JUNCTION CONNECTOR - MAIN BODY ECU)





(a) Disconnect the H103 No. 1 junction connector.
(b) Measure the resistance according to the value(s) in the table below.

Standard Resistance:





NG -- CHECK FOR SHORT IN CAN BUS WIRES (MAIN BODY ECU)
OK -- Continue to next step.

25. CHECK FOR SHORT IN CAN BUS WIRES (NO. 1 JUNCTION CONNECTOR - SKID CONTROL ECU)





(a) Disconnect the A59 No. 1 junction connector.
(b) Measure the resistance according to the value(s) in the table below.

Standard Resistance:





NG -- CHECK FOR SHORT IN CAN BUS WIRES (SKID CONTROL ECU)
OK -- Continue to next step.

26. CHECK FOR SHORT IN CAN BUS WIRES (NO. 1 JUNCTION CONNECTOR - STEERING ANGLE SENSOR)





(a) Disconnect the H94 No. 1 junction connector.
(b) Measure the resistance according to the value(s) in the table below.

Standard Resistance:





NG -- CHECK FOR SHORT IN CAN BUS WIRES (STEERING ANGLE SENSOR)
OK -- Continue to next step.

27. CHECK FOR SHORT IN CAN BUS WIRES (NO. 1 JUNCTION CONNECTOR - CENTER AIRBAG SENSOR)





(a) Disconnect the H90 No. 1 junction connector.
(b) Measure the resistance according to the value(s) in the table below.

Standard Resistance:





NG -- CHECK FOR SHORT IN CAN BUS WIRES (CENTER AIRBAG SENSOR)
OK -- REPAIR OR REPLACE NO. 1 JUNCTION CONNECTOR
28. CHECK FOR SHORT IN CAN BUS WIRES (SUSPENSION CONTROL ECU)





(a) w/ AVS
(1) Disconnect the O18 suspension control ECU connector.
(2) Measure the resistance according to the value(s) in the table below.

Standard Resistance:





(b) w/o AVS
(1) Disconnect the O19 suspension control ECU connector.
(2) Measure the resistance according to the value(s) in the table below.

Standard Resistance:





NG -- REPAIR OR REPLACE CAN MAIN WIRE CONNECTED TO SUSPENSION CONTROL ECU (CANH, CANL)
OK -- REPLACE SUSPENSION CONTROL ECU
29. CHECK FOR SHORT IN CAN BUS WIRES (COMBINATION METER ECU)





(a) Disconnect the H37 combination meter 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 COMBINATION METER ECU (CANH, CANL)
OK -- REPLACE COMBINATION METER ASSEMBLY
30. CHECK FOR SHORT IN CAN BUS WIRES (POWER STEERING ECU)





(a) Disconnect the H38 power steering ECU connector.
(b) Measure the resistance according to the value(s) in the table below.

Standard Resistance:





NG -- REPAIR OR REPLACE CAN BRANCH WIRE CONNECTED TO POWER STEERING ECU (CANH, CANL)
OK -- REPLACE POWER STEERING ECU
31. CHECK FOR SHORT IN CAN BUS WIRES (DISTANCE CONTROL ECU)





(a) Disconnect the A43 distance control ECU connector.
(b) Measure the resistance according to the value(s) in the table below.

Standard Resistance:





NG -- REPAIR OR REPLACE CAN BRANCH WIRE CONNECTED TO DISTANCE CONTROL ECU (CANH, CANL)
OK -- REPLACE DISTANCE CONTROL ECU
32. CHECK FOR SHORT IN CAN BUS WIRES (MAIN BODY ECU)





(a) Disconnect the H2 main body ECU connector.
(b) Measure the resistance according to the value(s) in the table below.

Standard Resistance:





NG -- REPAIR OR REPLACE CAN BRANCH WIRE CONNECTED TO MAIN BODY ECU (CANH, CANL)
OK -- REPLACE MAIN BODY ECU
33. CHECK FOR SHORT IN CAN BUS WIRES (SKID CONTROL ECU)





(a) Disconnect the A19 skid control ECU connector.
(b) Measure the resistance according to the value(s) in the table below.

Standard Resistance:





NG -- REPAIR OR REPLACE CAN BRANCH WIRE CONNECTED TO SKID CONTROL ECU (CANH, CANL)
OK -- REPLACE ABS AND TRACTION ACTUATOR ASSEMBLY
34. CHECK FOR SHORT IN CAN BUS WIRES (STEERING ANGLE SENSOR)





(a) Disconnect the H6 steering angle sensor connector.
(b) Measure the resistance according to the value(s) in the table below.

Standard Resistance:





NG -- REPAIR OR REPLACE CAN BRANCH WIRE CONNECTED TO STEERING ANGLE SENSOR (CANH, CANL)
OK -- REPLACE STEERING ANGLE SENSOR
35. CHECK FOR SHORT IN CAN BUS WIRES (CENTER AIRBAG SENSOR)





(a) Disconnect the H56 center airbag sensor connector.
(b) Measure the resistance according to the value(s) in the table below.

Standard Resistance:





NG -- REPAIR OR REPLACE CAN BRANCH WIRE CONNECTED TO CENTER AIRBAG SENSOR (CANH, CANL)
OK -- REPLACE CENTER AIRBAG SENSOR