Toyota RAV4 Service Manual: Short to b+ in can bus line

Description

There may be a short circuit between the can bus line and +b when there is resistance between terminals 6 (canh) and 16 (bat) or terminals 14 (canl) and 16 (bat) of the dlc3.

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.

1. Check can bus line for short to +b (dlc3 branch wire)

1. Disconnect the e68 no. 2 Junction connector.
2. Measure the resistance of the dlc3.

Standard resistance

2. Connect connector

1. Reconnect the e68 no. 2 Junction connector.

3. Check can bus line for short to +b (no. 1 Junction connector side)

1. Disconnect the a36 no. 1 Junction connector.
2. Measure the resistance of the dlc3.

Standard resistance

4. Connect connector

1. Reconnect the a36 no. 1 Junction connector.

5. check can bus line for short to +b (no. 3 junction connector, no. 4 junction connector side)

1. Disconnect the e70 no. 3 Junction connector.
2. Measure the resistance of the dlc3.

Standard resistance

 

6. Connect connector

1. Reconnect the e70 no. 3 Junction connector.

7. Check can bus line for short to +b (no. 4 Junction connector side)

1. Disconnect the e69 no. 4 Junction connector.
2. Measure the resistance of the dlc3.

Standard resistance

8. Connect connector

1. Reconnect the e69 no. 4 Junction connector.

9. Check can bus line for short to +b (no. 3 Junction connector - center airbag sensor assembly)

1. Disconnect the e70 no. 3 Junction connector.
2. Measure the resistance of the wire harness side connectors.

Standard resistance

10. Connect connector

1. Reconnect the e70 no. 3 Junction connector.

11. Check can bus line for short to +b (center airbag sensor assembly)

1. Disconnect the e45 center airbag sensor connector.
2. Measure the resistance of the dlc3.

Standard resistance

Replace center airbag sensor assembly

12. Check can bus line for short to +b (no. 1 Junction connector - ecm)

1. Disconnect the a36 no. 1 Junction connector.
2. Measure the resistance of the wire harness side connectors.

Standard resistance

13. Check can bus line for short to +b (no. 1 Junction connector - abs and traction actuator)

1. Measure the resistance of the wire harness side connectors.

Standard resistance

Repair or replace can main wire and connector (no. 1 Junction connector - no.

2 Junction connector)

14. Connect connector

1. Reconnect the a36 no. 1 Junction connector.

15. Check can bus line for short to +b (ecm)

1. Disconnect the a9 ecm connector.
2. Measure the resistance of the dlc3.

Standard resistance

Replace ecm

16. Connect connector

1. Reconnect the a36 no. 1 Junction connector.

17. Check can bus line for short to +b (abs and traction actuator)

1. Disconnect the a19 abs and traction actuator (skid control ecu) connector.
2. Measure the resistance of the dlc3.

Standard resistance

Replace abs and traction actuator (skid control ecu)

18. Connect connector

1. Reconnect the e70 no. 3 Junction connector.

19. Check can bus line for short to +b (no. 2 Junction connector - yaw rate sensor)

1. Disconnect the e68 no. 2 Junction connector.
2. Measure the resistance of the wire harness side connectors.

Standard resistance

20. Check can bus line for short to +b (no. 2 Junction connector - power steering ecu)

1. Measure the resistance of the wire harness side connectors.

Standard resistance

21. Check can bus line for short to +b (no. 2 Junction connector - main body ecu)

1. Measure the resistance of the wire harness side connectors.

Standard resistance

22. Check can bus line for short to +b (no. 2 Junction connector - air conditioning amplifier)

1. Measure the resistance of the wire harness side connectors.

Standard resistance

23. Check can bus line for short to +b (no. 2 Junction connector - steering angle sensor)

1. Measure the resistance of the wire harness side connectors.

Standard resistance

Repair or replace can main wire and connector (no. 2 Junction connector - no.

3 Junction connector)

24. Connect connector

1. Reconnect the e68 no. 2 Junction connector.

25. Check can bus line for short to +b (yaw rate sensor)

1. Disconnect the k6 yaw rate sensor connector.
2. Measure the resistance of the dlc3.

Standard resistance

Replace yaw rate sensor

26. Connect connector

1. Reconnect the e68 no. 2 Junction connector.

27. Check can bus line for short to +b (power steering ecu)

1. Disconnect the e18 power steering ecu connector.
2. Measure the resistance of the dlc3.

Standard resistance

Replace power steering ecu

28. Connect connector

1. Reconnect the e68 no. 2 Junction connector.

29. Check can bus line for short to +b (main body ecu)

1. Disconnect the e17 main body ecu connector.
2. Measure the resistance of the dlc3.

Standard resistance

Replace instrument panel junction block (main body ecu)

30. Connect connector

1. Reconnect the e68 no. 2 Junction connector.

31. Check can bus line for short to +b (air conditioning amplifier)

1. Disconnect the e37*1 or e36*2 air conditioning amplifier connector.

Hint:

• *1: For automatic air conditioning system.
• *2: For manual air conditioning system.

2. Measure the resistance of the dlc3.

Standard resistance

Replace air conditioning amplifier

32. Connect connector

1. Reconnect the e68 no. 2 Junction connector.

33. Check can bus line for short to +b (steering angle sensor)

1. Disconnect the e11 steering sensor connector.
2. Measure the resistance of the dlc3.

Standard resistance

Replace steering angle sensor

34. Check can bus line for short to +b (no. 4 Junction connector - 4wd control ecu)

Notice:

For vehicles without 4wd, go to "check can bus line for short to +b (no. 4 Junction connector - combination meter ecu)".

1. Measure the resistance of the wire harness side connectors.

Standard resistance

35. Check can bus line for short to +b (no. 4 Junction connector - combination meter ecu)

1. measure the resistance of the wire harness side connectors.

Standard resistance

36. Connect connector

1. Reconnect the e69 no. 4 Junction connector.

37. Check can bus line for short to +b (4wd control ecu)

1. Disconnect the e57 4wd control ecu connector.
2. Measure the resistance of the dlc3.

Standard resistance

Replace 4wd control ecu

38. Connect connector

1. Reconnect the e69 no. 4 Junction connector.

39. Check can bus line for short to +b (combination meter ecu)

1. Disconnect the e19 combination meter ecu connector.
2. Measure the resistance of the dlc3.

Standard resistance

Replace combination meter ecu