P0147
DTC P0147: Third HO2S (Sensor 3) Heater circuit Malfunction-'02-03 M/T models1. Reset the ECM.
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 wires at the Third HO2S (Sensor 3) 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 Third HO2S (Sensor 3) 4P connector.
6. At the Third HO2S (Sensor 3) side, measure resistance between the Third 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 2), and the Third HO2S (Sensor 3).
7. At the Third HO2S (Sensor 3) side, check for continuity between body ground and the Third 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).
NO - Go to step 8.
8. Turn the ignition switch ON (II).
9. Measure voltage between the Third 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 C1 and body ground.
Is there continuity?
YES - Repair short in the wire between the ECM (C1) and the Third HO2S (Sensor 3).
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 Third HO2S (Sensor 3) terminal No.4 and body ground.
Is there battery voltage?
YES - Go to step 14.
NO - Repair open in the wire between the Third HO2S (Sensor 3) and the No.4 (7.5 A) fuse.
14. Turn the ignition switch OFF.
15. Reconnect the Third 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 C1.
Is there 0.1 V or less?
YES - Repair open in the wire between the ECM (C1) and the Third HO2S (Sensor 3).
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.