DTC Troubleshooting: P1158 (48-6)

DTC P1158 (48-6):  A/F Sensor (Sensor 1) AFS- Terminal Low Voltage

1.Reset the ECM/PCM.

2.Start the engine.

Is DTC P1158 indicated?

YES - Go to 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/PCMn

3.Turn the ignition switch OFF.

4.Disconnect the A/F sensor (Sensor 1) 4P connector, and ECM/PCM connector A (31P).

5.Check for continuity between ECM/PCM connector terminal A16 and body ground.


Is there continuity?

YES - Repair short in the wire between the A/F sensor (Sensor 1) and the ECM/PCM (A16).n

NO - Go to 6.

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

Is DTC P1158 indicated?

YES - Update the ECM/PCM if it does not have the latest software, or substitute a known-good ECM/PCM, then recheck. If the symptom/indication goes away with a known-good ECM/PCM, replace the original  ECM/ PCM.n

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