P0144

DTC P0144: Third HO2S (Sensor 3) Circuit High Voltage-'02-03 M/T models

1. Reset the ECM.
2. Start the engine. Hold the engine at 3,000 rpm with no load (in neutral) until the radiator fan comes on.
3. Test-drive under following conditions.
- 55 - 65 mph (89 - 105 km/h) steady speed
- Transmission in 4th or 5th gear
- Until the readiness code or Temporary DTC P0144 and/or P0144 is set

4. Check for a Temporary DTC with the scan tool.

Is Temporary DTC P0144 and or P0144 indicated?

YES - Go to step 6.

NO - Go to step 5.

5. Check the Third HO2S (Sensor 3) output voltage at 3,000 rpm with the scan tool.

Does the voltage stay at 1.0 V or more?

YES - Go to step 6.

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.

6. Turn the ignition switch OFF.
7. Disconnect the Third HO2S (Sensor 3) 4P connector.




8. Connect the Third HO2S (Sensor 3) 4P connector terminals No.1 and No.2 with a jumper wire.
9. Turn the ignition switch ON (II).
10. Check the Third HO2S (Sensor 3) output voltage with the scan tool.

Is there 1.0 V or more?

YES - Go to step 11.

NO - Replace the Secondary HO2S (Sensor 2), and the Third HO2S (Sensor 3).

11. Turn the ignition switch OFF.




12. Connect ECM connector terminals C16 and C18 with a jumper wire.
13. Turn the ignition switch ON (II).
14. Check the Third HO2S (Sensor 3) output voltage with the scan tool.

Is there 1.0 V or more?

YES - 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.

NO - Repair open in the wire between the ECM (C16, C18) and the Third HO2S (Sensor 3).