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