P0141

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

1. Reset the PCM.
2. Start the engine.

Is DTC P0141 indicated?

YES - Go to step 3.

NO - Intermittent failure. The system is OK at this time. Check for poor connections or loose terminals at the secondary HO2S (Sensor 2) and at the PCM.

3. Check the No.4 ACG (10A) fuse in the under-dash fuse/relay box.

Is the fuse OK?

YES - Go to step 4.

NO - Replace the fuse and retest.

4. Turn the ignition switch OFF.
5. Disconnect the secondary HO2S (Sensor 2) 4P connector.




6. At the secondary HO2S (Sensor 2) side, measure resistance between HO2S 4P connector terminals No.3 and No.4.

Is there about 13 Ohms?

YES - Go to step 7.

NO - Replace the secondary HO2S (Sensor 2).




7. 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).

NO - Go to step 8.

8. Turn the ignition switch ON (II).




9. Measure voltage between secondary HO2S 4P connector terminals No.3 and No.4.

Is there battery voltage?

YES - Go to step 10.

NO - Go to step 13.

10. Turn the ignition switch OFF.
11. Disconnect PCM connector A (31P).




12. Check for continuity between PCM connector terminal A14 and body ground.

Is there continuity?

YES - Repair short in the wire between the PCM (A14) and the secondary HO2S (Sensor 2).

NO - Update the PCM if it does not have the latest software, or substitute a known-good PCM, then recheck. If the symptom/indication goes away with a known-good PCM, replace the original PCM.




13. Measure voltage between secondary HO2S (Sensor 2) 4P connector terminal No.4 and body ground.

Is there battery voltage?

YES - Go to step 14.

NO - Check the No.4 ACG (10A) 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.4 ACG (10A) fuse.

14. Turn the ignition switch OFF.
15. Reconnect the secondary HO2S (Sensor 2) 4P connector.
16. Disconnect PCM connector A (31P).
17. Turn the ignition switch ON (II).




18. Measure voltage between PCM connector terminal A14 and A5.

Is there battery voltage?

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

NO - Repair open in the wire between the PCM (A14) and the secondary HO2S (Sensor 2).