P0155

DTC P0135: Rear A/F Sensor (Bank 1, Sensor 1) Heater Circuit Malfunction (2004 - 2005 models)

DTC P0155: Rear A/F Sensor (Bank 2, Sensor 1) Heater Circuit Malfunction (2004 - 2005 models)

NOTE:
- Information marked with an asterisk (*) applies to the front bank (Bank 2).
- Before you troubleshoot, record all freeze data and any on-board snapshot, and review the general troubleshooting information.

1. Turn the ignition switch ON (II).
2. Clear the DTC with the HDS.
3. Start the engine.
4. Check for Temporary DTCs or DTCs with the HDS.

Is DTC P0135 and/or P0155* indicated?

YES - Go to step 5.

NO - Intermittent failure, system is OK at this time. Check for poor connections or loose terminals at the A/F sensor (Sensor 1), the A/F sensor relay (LAF), and the ECM/PCM.

5. Turn the ignition switch OFF.
6. Check these fuses:
- No.19 FI ECU (ECM/PCM) (40 A) fuse in the under-hood fuse/relay box.
- No.4 LAF (A/F SENSOR) (15 A) fuse in the under-dash fuse/relay box.
- No.23 IGP (7.5 A) fuse in the under-dash fuse/relay box.

Are any of the fuses blown?

YES - Repair short in the wire between the A/F sensors, the secondary HO2S, the A/F sensor relay (LAF), and the fuses, then replace the blown fuse(s), and go to step 23.

NO - Go to step 7.

7. Disconnect the A/F sensor (Sensor 1) 8P connector.




8. At the sensor side, measure resistance between A/F sensor (Sensor 1) 8p connector terminals No.1 and No.2.

Is there 2.5 - 3.2 Ohms at room temperature?

YES - Go to step 9.

NO - Go to step 22.




9. At the sensor side, check for continuity between each terminal at the A/F sensor (Sensor 1) 8P connector and body ground.

Is there continuity?

YES - Go to step 22.

NO - Go to step 10.




10. At the sensor side, check for continuity between A/F sensor (Sensor 1) 8P connector terminals No.1 and No.3, No.4, No.6, No.7, and No.8 individually.

Is there continuity?

YES - Go to step 22.

NO - Go to step 11.

11. Jump the SCS line with the HDS.
12. Disconnect ECM/PCM connector E (31P).




13. Check for continuity between ECM/PCM connector terminal E7 (E6)* and body ground.

Is there continuity?

YES - Repair short in the wire between the ECM/PCM (E7 (E6)*) and the A/F sensor (Sensor 1), then go to step 23.

NO - Go to step 14.




14. Connect A/F sensor (Sensor 1) 8P connector terminal No.2 to body ground with a jumper wire.




15. Check for continuity between ECM/PCM connector terminal E7 (E6) and body ground.

Is there continuity?

YES - Go to step 16.

NO - Repair open in the wire between the ECM/PCM (E7 (E6)* ) and the A/F sensor (Sensor 1), then go to step 23.




16. Connect A/F sensor (Sensor 1) 8P connector terminal No.1 to body ground with a jumper wire.




17. Remove the A/F sensor relay (LAF) (A).




18. Check for continuity between A/F sensor relay (LAF) 4P connector terminal No.2 and body ground.

Is there continuity?

YES - Go to step 19.

NO - Repair open in the wire between the A/F sensor (Sensor 1) and the A/F sensor relay (LAF), then go to step 23.

19. Disconnect ECM/PCM connector A (31P).




20. Check for continuity between ECM/PCM connector terminal A4 and A/F sensor relay (LAF) 4P connector terminal No.4.

Is there continuity?

YES - Go to step 21.

NO - Repair open in the wire between the ECM/PCM (A4) and the A/F sensor relay (LAF), then go to step 23.

21. Test the A/F sensor relay (LAF).

Is the A/F sensor relay (LAF) OK?

YES - Go to step 29.

NO - Replace the A/F sensor relay (LAF), then go to step 23.

22. Replace the A/F sensor (Sensor 1)
23. Reconnect all connectors.
24. Turn the ignition switch ON (II).
25. Reset the ECM/PCM with the HDS.
26. Do the ECM/PCM idle learn procedure.
27. Check for Temporary DTCs or DTCs with the HDS.

Are any Temporary DTCs or DTCs indicated?

YES - If DTC P0135 and/or P0155* is indicated, check for poor connections or loose terminals at the A/F sensor (Sensor 1), the A/F sensor relay (LAF), and the ECM/PCM, then go to step 1. If any other Temporary DTCs or DTCs are indicated, go to the indicated DTC's troubleshooting.

NO - Go to step 28.

28. Monitor the OBD STATUS for DTC P0135 and/or P0155* in the DTCs MENU with the HDS.

Does the screen indicate PASSED?

YES - Troubleshooting is complete.

NO - If the screen indicates FAILED, check for poor connections or loose terminals at the A/F sensor (Sensor 1), the A/F sensor relay (LAF), and the ECM/PCM, then go to step 1. If the screen indicates NOT COMPLETED, go to step 26 and recheck.

29. Update the ECM/PCM if it does not have the latest software, or substitute a known-good ECM/PCM.
30. Check for Temporary DTCs or DTCs with the HDS.

Are any Temporary DTCs or DTCs indicated?

YES - If DTC P0135 and/or P0155* is indicated, check for poor connections or loose terminals at the A/F sensor (Sensor 1), the A/F sensor relay (LAF), and the ECM/PCM, then go to step 1. If any other Temporary DTCs or DTCs are indicated, go to the indicated DTC's troubleshooting.

NO - If the ECM/PCM was updated, troubleshooting is complete. If the ECM/PCM was substituted, replace the original ECM/PCM.