P0141

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

'02-04 Models

NOTE: Information marked with an asterisk (*) applies to the D17A2 engine.

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

Is DTC P0141 indicated?

YES - Go to step 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.

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




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

YES - Go to step 8.

NO - Go to step 7.




7. Check for continuity between body ground and secondary HO2S (Sensor 2) 4P connector terminals No. 4.

Is there continuity?

YES - Repair short in the wire between the secondary HO2S (Sensor 2) and the No. 4 ACG (10 A) fuse, and replace the No. 4 ACG (10 A) fuse.

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

8. Turn the ignition switch OFF.
9. Reconnect the secondary HO2S (Sensor 2) 4P connector.
10. Disconnect ECM/PCM connector A (31P) (ECM/PCM connector E, 31P)*.
11. Turn the ignition switch ON (II).




12. Measure voltage between body ground and ECM/PCM connector terminal A14 (E6)*.

Is there battery voltage?

YES - Go to step 16.

NO - Go to step 13.

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




15. Check for continuity between body ground and ECM/PCM connector terminal A14 (E6)*.

Is there continuity?

YES - Repair short in the wire between ECM/PCM (A14, E6)* and secondary HO2S (Sensor 2).

NO - Repair open in the wire between ECM/PCM (A14, E6)* and secondary HO2S (Sensor 2).

16. Substitute a known-good secondary HO2S (Sensor 2) and recheck.

Is DTC P0141 indicated?

YES - 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.

NO - Replace the secondary HO2S (Sensor 2) and the third HO2S (Sensor 3) (D17A6 engine '01 model).