P0135

DTC P0135: Malfunction in Primary HO2S (Sensor 1) Heater circuit

NOTE: Information marked with an asterisk ( * ) applies to DTC P0141.

1. Do the ECM/PCM Reset Procedure.
2. Start the engine.
Is DTC P0135 or P0141 indicated?
YES-Go to step 3.
NO-Intermittent failure, system is OK at this time.
Check for poor connections or loose wires at C204 (located under the right side of the dash), C101, C102 (located at the left side of the engine compartment), the Primary HO2S (Sensor 1), the Secondary HO2S (Sensor 2) and the ECM/PCM.
3. Turn the ignition switch OFF.
4. Disconnect the HO2S (Primary or Secondary *) (Sensor 1 or Sensor 2 *) 4P connector.




5. At the HO2S side, measure resistance between the HO2S 4P connector terminals No.3 and No.4.
Is there 10 - 40 Ohm?
YES-Go to step 6.
NO-Replace the Primary HO2S (Sensor 1) or Secondary HO2S (Sensor 2)*.




6. Check continuity between body ground and the HO2S 4P connector terminals No.3 and No.4 individually.
Is there continuity?
YES-Replace the HO2S (Primary or Secondary *) (Sensor 1 or Sensor 2 *).
NO-Go to step 7.
7. Start the engine.




8. Measure voltage between the HO2S 4P connector terminal No.4 and body ground.
Is there battery voltage?
YES-Go to step 9.
NO- Repair open in the wire between the No.6 ECU (ECM/PCM) CRUISE CONTROL (15 A) fuse and the HO2S.
9. Turn the ignition switch OFF.




10. Check for continuity between the HO2S 4P connector terminal No.3 and body ground.
IS there continuity?
YES-Go to step 11.
NO-Go to step 13.
11. Disconnect the ECM/PCM connector C (31P) (ECM/ PCM connector A, 32P)*.




12. Check for continuity between the HO2S 4P connector terminal No.3 and body ground.
Is there continuity?
YES-Repair short in the wire between the ECM/PCM (C1, A8 * ) and HO2S (Primary or Secondary * ) (Sensor 1, Sensor 2 * ).
NO-Substitute a known-good ECM/PCM and recheck. If the symptom/indication goes away, replace the original ECM/PCM.
Diagnostic Strategies

13. Reconnect the HO2S (Primary or Secondary *) (Sensor 1, Sensor 2 *) 4P connector.
14. Disconnect the ECM/PCM connector C (31P) (ECM/ PCM connector A, 32P)*.
15. Turn the ignition switch ON (II).




16. Measure voltage between the ECM/PCM connector terminal C1 (A8) * and body ground.
Is there battery voltage?
YES-Substitute a known-good ECM/PCM and recheck. If the symptom/indication goes away, replace the original ECM/PCM.
Diagnostic Strategies

NO-Repair open in the wire between the ECM/PCM (C1, A8 *) and HO2S (Primary or Secondary *) (Sensor 1, Sensor 2 *).