P0147
DTC P0147: Third HO2S (Sensor 3) Heater Circuit Malfunction1. Reset the ECM/PCM.
2. Start the engine.
Is DTC P0147 indicated?
YES - Go to step 3.
NO - Intermittent failure, system is OK at this time. Check for poor connections or loose terminals at the third HO2S (Sensor 3) and at the ECM/PCM.
3. Turn the ignition switch OFF.
4. Disconnect the third HO2S (Sensor 3) 4P connector.
5. Turn the ignition switch ON (II).
6. Measure voltage between third HO2S (Sensor 3) 4P connector terminal No. 4 and body ground.
Is there battery voltage?
YES - Go to step 8.
NO - Go to step 7.
7. Check for continuity between body ground and third HO2S (Sensor 3) 4P connector terminal No. 4.
Is there continuity?
YES - Repair short in the wire between the third HO2S (Sensor 3) 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 third HO2S (Sensor 3) and the No.4 ACG (10 A)fuse.
8. Turn the ignition switch OFF.
9. Reconnect the third HO2S (Sensor 3) 4P connector.
10. Disconnect ECM/PCM connector E (31P).
11. Turn the ignition switch ON (II).
12. Measure voltage between body ground and ECM/PCM connector terminal E6.
Is there battery voltage?
YES - Go to step 16.
NO - Go to step 13.
13. Turn the ignition switch OFF.
14. Disconnect the third HO2S (Sensor 3) 4P connector.
15. Check for continuity between body ground and ECM/PCM connector terminal E6.
Is there continuity?
YES - Repair short in the wire between ECM/PCM (E6) and third HO2S (Sensor 3).
NO - Repair open in the wire between ECM/PCM (E6) and third HO2S (Sensor 3).
16. Substitute a known-good third HO2S (Sensor 3) and recheck.
Is DTC P0147 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).