P1159

DTC P1159: A/F Sensor (Sensor 1) PHO2S + Circuit Low Voltage-'02-03 M/T models and 01-03 CVT Models

1. Reset the ECM.
2. Start the engine, and wait at least 2 minutes.

Is DTC P1159 indicated?

YES - Go to step 3.

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

3. Turn the ignition switch OFF.
4. Disconnect the A/F Sensor 4P connector and ECM connector D (16P).




5. Check for continuity between A/F Sensor (Sensor 1) 4P connector terminal No.2 and body ground.

Is there continuity?

YES - Repair short in the wire between the A/F Sensor (Sensor 1) and the ECM (D4).

NO - Go to step 6.

6. Substitute a known-good A/F Sensor (Sensor 1) and recheck.

Is DTC P1158 indicated?

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