P0147
DTC P0147: Third HO2S (Sensor 3) Heater Circuit Malfunction(ULEV model)
1. Reset the ECM with the HDS.
2. Start the engine.
3. Check for a Temporary DTCs or DTCs with the HDS.
Is DTC P0147 indicated?
YES - Go to step 4.
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.
4. Check the No.4 FI-ECU (10 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 third HO2S (Sensor 3) 4P connector.
7. At the third HO2S (Sensor 3) side, measure resistance between third HO2S 4P connector terminals No.3 and No.4.
Is there about 6 Ohms at room temperature?
YES - Go to step 8.
NO - Replace the secondary HO2S (Sensor 2) and the third HO2S (Sensor 3).
8. At the third HO2S (Sensor 3) side, check for continuity between body ground and third HO2S (Sensor 3) 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 9.
9. Turn the ignition switch ON (II).
10. Measure voltage between third HO2S (Sensor 3) 4P connector terminals No.3 and No.4.
Is there battery voltage?
YES - Go to step 11.
NO - Go to step 15.
11. Turn the ignition switch OFF.
12. Wait for 1 minute. If the radiator fan is running, wait for 1 minute after it stops.
13. Disconnect ECM connector E (31P).
14. Check for continuity between ECM connector terminal E6 and body ground.
Is there continuity?
YES - Repair short in the wire between the ECM (E6) 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.
15. Measure voltage between third HO2S (Sensor 3) 4P connector terminal No.4 and body ground.
Is there battery voltage?
YES - Go to step 16.
NO - Check the No.4 FI-ECU (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 FI-ECU (10 A) fuse.
16. Turn the ignition switch OFF.
17. Wait for 1 minute. If the radiator fan is running, wait for 1 minute after it stops.
18. Reconnect the third HO2S (Sensor 3) 4P connector.
19. Disconnect ECM connectors A (31P) and E (31P).
20. Turn the ignition switch ON (II).
21. Measure voltage between ECM connector terminals AS and E6.
Is there 0.1 V or less?
YES - Repair open in the wire between the ECM (E6) 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.