## DTC Troubleshooting: P0141 (65-2)

DTC P0141 (65-2): | Secondary HO2S (Sensor 2) Heater Circuit Malfunction

1. | Reset the ECM/PCM.

2. | Start the engine. Is DTC P0141 indicated? YES - Go to 3. NO - Intermittent failure, system is OK at this time. Check for poor connections or loose terminals at the secondary HO2S (Sensor 2) and at the ECM/PCM.n

3. | Turn the ignition switch OFF.

4. | Disconnect the secondary HO2S (Sensor 2) 4P connector.

5. | At the secondary HO2S (Sensor 2) side, measure resistance between the HO2S 4P connector terminals No. 3 and No. 4. Is there about 11 W (at room temperture)? YES - Go to 6. NO - Replace the secondary HO2S (Sensor 2).n

6. | Check continuity between body ground and the secondary HO2S (Sensor 2) 4P connector terminals No. 3 and No. 4 individually. Is there continuity? YES - Replace the secondary HO2S (Sensor 2).n NO - Go to 7.

7. | Turn the ignition switch ON (II).

8. | Measure voltage between the secondary HO2S 4P connector terminals No. 3 and No. 4. Is there battery voltage? YES - Go to 9. NO - Go to 12.

9. | Turn the ignition switch OFF.

10. | Disconnect ECM/PCM connector E (31P).

11. | Check for continuity between ECM/PCM connector terminal E6 and body ground. Is there continuity? YES - Repair short in the wire between the ECM/PCM (E6) and the secondary HO2S (Sensor 2).n NO - Update the ECM/PCM if it does not have the latest software, or substitute a known-good ECM/PCM, then recheck. If the symptom/indication goes away with a known-good ECM/PCM, replace the original ECM/ PCM.n

12. | Measure voltage between the secondary HO2S (Sensor 2) 4P connector terminal No. 4 and body ground. Is there battery voltage? YES - Go to 13. NO - Check the No. 16 ACG (7.5A) fuse in the under-dash fuse/relay box. If the fuse is OK, repair open in the wire between the secondary HO2S (Sensor 2) and No. 16 ACG (7.5A) fuse.n

13. | Turn the ignition switch OFF.

14. | Reconnect the secondary HO2S (Sensor 2) 4P connector.

15. | Disconnect ECM/PCM connector E (31P).

16. | Turn the ignition switch ON (II).

17. | Measure voltage between ECM/PCM connector terminal E6 and A5. Is there 0.1 V or less? YES - Repair open in the wire between the ECM/PCM (E6) and the secondary HO2S (Sensor 2).n NO - Update the ECM/PCM if it does not have the latest software, or substitute a known-good ECM/PCM, then recheck. If the symptom/indication goes away with a known-good ECM/PCM, replace the original ECM/ PCM.n