| DTC P0135: | A/F Sensor (Sensor 1) Heater Circuit Malfunction |
| 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 (min-1) without load (in 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 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 under-hood fuse/relay box, and the ECM.n |
| 5. | Turn the ignition switch OFF. |
| 6. | Check the No. 13 LAF (A/F SENSOR) (15 A) fuse in the under-hood fuse/relay box. Is the fuse OK? YES - Go to 7. NO - Go to 18. |
| 7. | Test the PGM-FI subrelay in the under-hood fuse/relay box. Is the PGM-FI subrelay OK? YES - Go to 8. NO - Replace the under-hood fuse/relay box, then go to 22. |
| 8. | Disconnect the A/F sensor (Sensor 1) 4P connector. |
| 9. | At the sensor side, measure resistance between A/F sensor (Sensor 1) 4P connector terminals No. 3 and No. 4.
Is there 1.9-2.5 W at room temperature? YES - Go to 10. NO - Go to 21. |
| 10. | 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 21. NO - Go to 11. |
| 11. | Jump the SCS line with the HDS. |
| 12. | Disconnect ECM connector C (44P). |
| 13. | Check for continuity between A/F sensor (Sensor 1) 4P connector terminal No. 3 and ECM connector terminal C9.
Is there continuity? YES - Go to 14. NO - Repair open in the wire between the ECM (C9) and the A/F sensor (Sensor 1), then go to 22. |
| 14. | Disconnect the under-hood fuse/relay box 20P (white) connector. |
| 15. | Check for continuity between A/F sensor (Sensor 1) 4P connector terminal No. 4 and under-hood fuse/relay box 20P (white) connector terminal No. 9.
Is there continuity? YES - Go to 16. NO - Repair open in the wire between the A/F sensor (Sensor 1) and the under-hood fuse/relay box, then go to 22. |
| 16. | Disconnect ECM connector A (44P). |
| 17. | Check for continuity between under-hood fuse/relay box 20P (white) connector terminal No. 20 and ECM connector terminal A21.
Is there continuity? YES - Go to 28. NO - Repair open in the wire between the ECM (A21) and the under-hood fuse/relay box, then go to 22. |
| 18. | Disconnect the under-hood fuse/relay box 20P (white) connector. |
| 19. | Disconnect the A/F sensor (Sensor 1) 4P connector. |
| 20. | Check for continuity between A/F sensor (Sensor 1) 4P connector terminal No. 4 and body ground.
Is there continuity? YES - Repair short in the wire between the under-hood fuse/relay box and the A/F sensor (Sensor 1). Also replace the No. 13 LAF (A/F SENSOR) (15 A) fuse, then go to 22. NO - Replace the under-hood fuse/relay box, then go to 22. |
| 21. | Replace the A/F sensor (Sensor 1). |
| 22. | Reconnect all connectors and the battery. |
| 23. | Turn the ignition switch ON (II). |
| 24. | Reset the ECM with the HDS. |
| 25. | Do the ECM idle learn procedure. |
| 26. | Check for Temporary DTCs or DTCs with the HDS. Are any Temporary DTCs or DTCs indicated? YES - If DTC P0135 is indicated, check for poor connections or loose terminals at the A/F sensor (Sensor 1), the under-hood fuse/relay box, and the ECM, then go to 1. If any other Temporary DTCs or DTCs are indicated, go to the indicated DTC's troubleshooting. NO - Go to 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.n NO - If the screen indicates FAILED, check for poor connections or loose terminals at the A/F sensor (Sensor 1), the under-hood fuse/relay box, and the ECM, then go to 1. If the screen indicates NOT COMPLETED, go to 25 and recheck. |
| 28. | Update the ECM if it does not have the latest software, or substitute a known-good ECM. |
| 29. | Check for Temporary DTCs or DTCs with the HDS. Are any Temporary DTCs or DTCs indicated? YES - If DTC P0135 is indicated, check for poor connections or loose terminals at the A/F sensor (Sensor 1), the under-hood fuse/relay box, and the ECM, then go to 1. If any other Temporary DTCs or DTCs are indicated, go to the indicated DTC's troubleshooting. NO - If the ECM was updated, troubleshooting is complete. If the ECM was substituted, replace the original ECM.n |