P0135

DTC P0135: A/F Sensor (Sensor 1) Heater Circuit Malfunction - 2004 model

NOTE: Information marked with an asterisk (*) applies to 2002-2003 models.

1. Reset the ECM.
2. Start the engine.

Is DTC P0135 (P1166)* indicated?

YES - Go to step 3.

NO - Intermittent failure, system is OK at this time. Check for poor connections or loose wires at C102 (located under the right side of the dash) the A/F Sensor relay, the A/P Sensor (Sensor 1) and the ECM.

3. Check the following fuse:
- NO. 16 (30 A) fuse in under-hood fuse/relay box.
- NO. 14 (30 A) fuse in under-dash fuse/relay box.
- NO. 4 (7.5 A) in 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.

NO - Go to step 4.




4. Measure voltage between ECM connector terminals D5 and B20, 30 seconds after the ignition switch is turned ON (II).

Is there battery voltage?

YES - Update the ECM if it does not have the latest software, or substitute a known-good ECM, then recheck. If the symptom/indication goes away with a known-good ECM, replace the original ECM.

NO - Go to step 5.




5. Measure voltage between ECM connector terminals D11 and B20.

Is there battery voltage?

YES - Go to step 6.

NO - Go to step 10.

6. Turn the ignition switch OFF.
7. Disconnect the ECM connector A (32P).
8. Turn the ignition switch ON (II).




9. Connect ECM connector terminal A11 to body ground with a jumper wire, then measure voltage between ECM connector terminals D5 and B20.

Is there battery voltage?

YES - Update the ECM if it does not have the latest software, or substitute a known-good ECM, then recheck. If the symptom/indication goes away with a known-good ECM, replace the original ECM.

NO - Repair open or short in the wire between A/F Sensor (Sensor 1) and ECM (D5).

10. Turn the ignition switch OFF.
11. Disconnect the ECM connector D (16P) and the A/F Sensor (Sensor 1) 4P connector.




12. Check for continuity between the A/F Sensor (Sensor 1) 4P connector terminal No. 4 and body ground.

Is there continuity?

YES - Repair short in the wire between the A/F Sensor relay, A/F Sensor (Sensor 1) and ECM (D11).

NO - Go to step 13.

13. Turn the ignition switch ON (II).




14. Measure voltage between ECM connector terminals A11 and B20.

Is there battery voltage?

YES - Repair open in the wire between the ECM (D11) and the A/F Sensor (Sensor 1).

NO - Go to step 15.

15. Check for continuity in the wires between the A/F Sensor and the fuses.

Is there continuity?

YES - The wires are OK. Replace the A/F Sensor relay.

NO - Repair open in the wire between the A/F Sensor relay and the fuses.