DTC Troubleshooting
DTC P0135:A/F Sensor (Sensor 1) Heater Circuit MalfunctionNOTE: 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. Hold the engine speed at 3,000 rpm without load (in Park or neutral) until the radiator fan comes on, then let it idle.
4. Check for Temporary DTCs or DTCs with the HDS.
Is DTC P0135 indicated?
YES - Go to step 5.
NO - Intermittent failure, the 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 and the ECM/PCM.
5. Turn the ignition switch OFF.
6. Check these fuses:
- No. 19 OPTION (40 A) fuse in the under-hood fuse/relay box.
- No. 4 LAF (10 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 sensor relay and the fuses. Also replace the blown fuse, then Go to step 22.
NO - Go to step 7.
7. Disconnect the A/F sensor (Sensor 1) 4P connector.
8. At the sensor side, measure resistance between A/F sensor (Sensor 1) 4P connector terminals No. 3 and No. 4.
Is there 2.1 - 2.9 ohms at room temperature?
YES - Go to step 9.
NO - Go to step 21.
9. At the sensor side, check for continuity between A/F sensor (Sensor 1) 4P connector terminals No. 1 and No. 3, and between terminals No. 1 and No. 4 individually.
Is there continuity?
YES - Go to step 21.
NO - Go to step 10.
10. Jump the SCS line with the HDS.
11. Disconnect ECM/PCM connector A (31P).
12. Check for continuity between ECM/PCM connector terminal A10 and body ground.
Is there continuity?
YES - Repair short in the wire between the ECM/PCM (A10) and the A/F sensor (Sensor 1), then Go to step 22.
NO - Go to step 13.
13. Connect A/F sensor (Sensor 1) 4P connector terminal No. 3 to body ground with a jumper wire.
14. Check for continuity between ECM/PCM connector terminal A10 and body ground.
Is there continuity?
YES - Go to step 15.
NO - Repair open in the wire between the ECM/PCM (A10) and the A/F sensor (Sensor 1), then Go to step 22.
15. Remove the left kick panel, then remove the A/F sensor relay (A) from the underdash fuse/relay box.
16. Connect A/F sensor (Sensor 1) 4P connector terminal No. 4 to body ground with a jumper wire.
17. Check for continuity between A/F sensor relay 4P connector terminal No. 2 and body ground.
Is there continuity?
YES - Go to step 18.
NO - Repair open in the wire between the A/F sensor (Sensor 1) and the A/F sensor relay, then Go to step 22.
18. Disconnect ECM/PCM connector E(31P).
19. Check for continuity between ECM/PCM connector terminal E8 and A/F sensor relay 4P connector terminal No. 3.
Is there continuity?
YES - Go to step 20.
NO - Repair open in the wire between the ECM/PCM (E8) and the A/F sensor relay, then Go to step 22.
20. Check the A/F sensor relay.
Is the A/F sensor relay OK?
YES - Go to step 28.
NO - Replace the A/F sensor relay, then Go to step 22.
21. Replace the A/F sensor (Sensor 1).
22. Reconnect all connectors.
23. Turn the ignition switch ON (II).
24. Reset the ECM/PCM with the HDS.
25. Do the ECM/PCM idle learn procedure.
26. Check for Temporary DTCs or DTCs with the HDS.
Is DTC P0135 indicated?
YES - Check for poor connections or loose terminals at the A/F sensor (Sensor 1), the A/F sensor relay, and the ECM/PCM, then Go to step 1.
NO - Go to step 27.
27. Monitor the OBD STATUS for DTC P0135 in the DTCs MENU with the HDS.
Does the screen indicate PASSED?
YES - Troubleshooting is complete. If any other Temporary DTCs or DTCs were indicated in step 26, Go to the indicated DTC's troubleshooting.
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, and the ECM/PCM, then Go to step 1. If the screen indicates NOT COMPLETED, keep idling until a result comes on.
28. Reconnect all connectors.
29. Update the ECM/PCM if it does not have the latest software, or substitute a known good ECM/PCM.
30. Start the engine, and let it idle.
31. Check for Temporary DTCs or DTCs with the HDS.
Is DTC P0135 indicated?
YES - Check for poor connections or loose terminals at the A/F sensor (Sensor 1), the A/F sensor relay, and the ECM/PCM. If the ECM/PCM was updated, substitute a known good ECM/PCM, then recheck. If the ECM/PCM was substituted, Go to step 1.
NO - Go to step 32.
32. Monitor the OBD STATUS for DTC P0135 in the DTCs MENU with the HDS.
Does the screen indicate PASSED?
YES - If the ECM/PCM was updated, troubleshooting is complete. If the ECM/PCM was substituted, replace the original ECM/PCM. If any other Temporary DTCs or DTCs were indicated in step 31, Go to the indicated DTC's troubleshooting.
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, and the ECM/PCM. If the ECM/PCM was updated, substitute a known good ECM/PCM, then Go to step 31. If the ECM/PCM was substituted, Go to step 1. If the screen indicates NOT COMPLETED, keep idling until a result comes on.