P1166

DTC P1166: A/F Sensor (Sensor 1) Heater Circuit Malfunction (2000-2001 M/T models)

NOTE: Before you troubleshoot, record all freeze data and review the general trouble shooting information.

1. Reset the ECM with the HDS.
2. Start the engine.
3. Check for temporary DTCs or DTCs with the HDS.

Is DTC P1166 indicated?

YES - Go to step 4.

NO - Intermittent failure, system is OK at this time. Check for poor connections or loose terminals at the A/F sensor (Sensor 1) and at the ECM.

4. Turn the ignition switch OFF.
5. Disconnect the AF sensor (Sensor 1) 8P connector.




6. At the sensor side, measure resistance between the A/F sensor (Sensor 1) 8P connector terminals No.1 and No.2.

Is there 2 - 13 Ohms ?

YES - Go to step 7.

NO - Replace the A/F sensor (Sensor 1).




7. At the sensor side, check for continuity between each terminal at the A/F sensor (Sensor 1) 8P connector and body ground.

Is there continuity?

YES - Replace the A/F sensor (Sensor 1).

NO - Go to step 8.




8. At the sensor side, check for continuity between the A/F sensor (Sensor 1) 8P connector terminals No.1 and No.3, No.4, No.6, No.7 and No.8 individually.

Is there continuity?

YES - Replace the A/F sensor (Sensor 1).

NO - Go to step 9.

9. Start the engine, and let it idle.




10. Measure voltage between the A/F sensor (Sensor 1) 8P connector terminal No.1 and body ground.

Is there more than 5.0 V?

YES - Go to step 16.

NO - Go to step 11.

11. Turn the ignition switch OFF.
12. Disconnect ECM connector D (16P).




13. Check for continuity between ECM connector terminal D5 and body ground.

Is there continuity?

YES - Repair short in the wire between the ECM (D5) and the A/F sensor (Sensor 1).

NO - Go to step 14




14. Connect ECM connector terminal D5 to body ground with a jumper wire.




15. Check for continuity between the A/F Sensor (Sensor 1) 8P connector terminal No.1 and body ground.

Is there more than 5.0 V?

YES - Substitute a known-good ECM and recheck. If symptom/indication goes away, replace the original ECM.

NO - Repair open in the wire between the ECM (D5) and the A/F sensor (Sensor 1).




16. Measure voltage between the A/F sensor (Sensor 1) 8P connector terminals No.1 and No.2.

Is there more than 5.0 V?

YES - Substitute a known-good ECM and recheck. If symptom/indication goes away, replace the original ECM.

NO - Repair open in the wire between the A/F sensor (Sensor 1) and G101.