Diagnostic Trouble Code (DTC) Information

Diagnostic trouble code (DTC) information

Condition
Diagnostic trouble code (DTC) ECM-8D is stored if the idling speed is too high or too low when the throttle position (TP) sensor is in the closed position.

Substitute value
- No fuel trim adaptation
- Limited EVAP control
- The conditions for fuel shut-off are changed.

Possible source

Signal too low:
- The idle air control (IAC) valve sticks in the closed position
- Blocked hoses
- Contact resistance.

Signal too high:
- The idle air control (IAC) valve sticks in the open position
- Defective throttle position (TP) sensor
- Air leakage in the intake system.

Fault symptom[s]
- Low idling speed
- High idling speed.