P1159
DTC P1159: A/F Sensor (Sensor 1) AFS + Terminal Low Voltage1. Reset the ECM.
2. Start the engine.
Is DTC P1159 indicated?
YES - Go to step 3.
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.
3. Turn the ignition switch OFF.
4. Disconnect the A/F sensor (Sensor 1) 4P connector and ECM connector A (31P).
5. Check for continuity between ECM connector terminal A6 and body ground.
Is there continuity?
YES - Repair short in the wire between the A/F sensor (Sensor 1) and the ECM (A6).
NO - Go to step 6.
6. Substitute a known-good A/F sensor (Sensor 1) and recheck.
Is DTC P1159 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).