P0141

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

1. Reset the ECM with the HDS.
2. Start the engine.
3. Check for Temporary DTCs or DTCs with the HDS.

Is DTC P0141 indicated?

YES - Go to step 4.

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

4. Check the No.4 (7.5 A) fuse in the under-dash fuse/relay box.

Is the fuse OK?

YES - Go to step 5.

NO - Replace the fuse and retest.

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




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

Is there about 10 - 40 ohm?

YES - Go to step 8.

NO - Replace the secondary HO2S (Sensor 2), and the third HO2S (Sensor 3) *1.
* 1: 2002-2005 M/T models




8. At the secondary HO2S (Sensor 2) side, check for continuity between body ground and secondary HO2S (Sensor 2) 4P connector terminals No.3 and No.4 individually.

Is there continuity?

YES - Replace the secondary HO2S (Sensor 2), and the third HO2S (Sensor 3)*1.
* 1: 2002-2005 M/T models

NO - Go to step 9.

9. Turn the ignition switch ON (II).




10. Measure voltage between secondary HO2S (Sensor 2) 4P connector terminals No.3 and No.4.

Is there battery voltage?

YES - Go to step 11.

NO - Go to step 14.

11. Turn the ignition switch OFF.
12. Disconnect ECM connector C (31P).




13. Check for continuity between ECM connector terminal C12 and body ground.

Is there continuity?

YES - Repair short in the wire between the ECM (C12) and the secondary HO2S (Sensor 2).

NO - 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.




14. Measure voltage between secondary HO2S (Sensor 2) 4P connector terminal No.4 and body ground.
15. Turn the ignition switch OFF.
16. Reconnect the secondary HO2S (Sensor 2) 4P connector.
17. Disconnect ECM connector C (31P).
18. Turn the ignition switch ON (II).




19. Measure voltage between ECM connector terminals B2and C12.

Is there 0.1 V or less?

YES - Repair open in the wire between the ECM (C12) and the secondary HO2S (Sensor 2).

NO - 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.