KE1 - Check For RPM Drop

Diagnostic Trouble Code (DTC) 412 indicates that during Engine Running Self-Test, engine rpm could not be controlled within the Self-Test upper limit band.

Possible causes:

- Open or shorted circuit.

- Throttle linkage binding.

- Improper idle airflow set.

- Idle Air Control (IAC) solenoid contamination.

- Items external to Idle Air Control system that could affect engine rpm.

- Damaged IAC solenoid.

- Damaged Powertrain Control Module (PCM).

- Key "OFF".

- Connect engine tachometer.

- Start engine.

- Disconnect IAC harness connector.

- Does rpm drop or stall?

Yes -- Go to KE2. KE2 - Check For Other DTCs

No -- Go to KE3. KE3 - Check For Other DTCs