P0509

Test 1 - 2:

Test 3 - 6:

SYMPTOM
P0509 - IAC VALVE SIGNAL CIRCUIT HIGH

WHEN MONITORED
Engine running. Battery voltage greater than 10 volts. IAC motor operating.

SET CONDITION
The PCM senses a short to ground or battery voltage on the Linear Idle Air Control (LIAC) control circuit for 2.75 seconds while the IAC motor is active.

POSSIBLE CAUSES
- IAC motor operation
- IAC motor
- (K60) IAC signal circuit shorted to voltage
- (K39) IAC control circuit shorted to voltage
- (K39) IAC control circuit shorted to (K60) IAC signal circuit
- PCM