P0141
DTC P0141: Secondary HO2S (Sensor 2) Heater circuit Malfunction1. Reset the ECM.
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 wires at the Secondary HO2S (Sensor 2) and at the ECM.
3. Check the No.4 (7.5 A) 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 the Secondary HO2S 4P connector terminals No.3 and No.4.
Is there about 10 - 40 Ohms?
YES - Go to step 7.
NO - Replace the Secondary HO2S (Sensor 21, and the Third HO2S (Sensor 3) *1.
* 1:'02-03 M/T models
7. At the HO2S side, check for continuity between body ground and the Secondary HO2S 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: '02-03 M/T models
NO - Go to step 8.
8. Turn the ignition switch ON (II).
9. Measure voltage between the Secondary HO2S 4P connector terminal 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 ECM connector C (31P).
12. 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.
13. Measure voltage between the Secondary HO2S (Sensor 2) terminal No.4 and body ground.
Is there battery voltage?
YES - Go to step 14.
NO - Repair open in the wire between the Secondary HO2S (Sensor 2) and the No.4 (7.5 A) fuse.
14. Turn the ignition switch OFF.
15. Reconnect the Secondary HO2S 4P connector.
16. Disconnect ECM connector C (31P).
17. Turn the ignition switch ON (II).
18. Measure voltage between ECM connector terminals B2 and 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.