P1509 GMC - Idle Speed High Idle Air Control System Not Responding
P1509 GMC Possible Causes
- Faulty Idle Air Control (IAC)
- Idle Air Control Valve harness is open or shorted
- Idle Air Control Valve circuit poor electrical connection
First diagnose P1509 GMC code
Check the "Possible Causes" listed above. Visually inspect the related wiring harness and connectors. Check for damaged components and look for broken, bent, pushed out, or corroded terminals.
Cost of diagnosing the P1509 GMC code
Labor: 1.0The cost of diagnosing the P1509 GMC code is 1.0 hour of labor. The auto repair labor rates vary widely across the country, and even within the same city. Most auto repairs shops charge between $75 and $150 per hour.
P1509 GMC Possible Symptoms
- Engine Light ON (or Service Engine Soon Warning Light)
- Engine rough idle
P1509 GMC MeaningWith the engine runtime 2 minutes, closed throttle, Engine Coolant Temperature (ECT) input over 122°F, Intake Air Temperature (IAT) over 62°F, VSS under 3 mph, the Powertrain Control Module (PCM) detects that the Actual idle speed was 175 rpm higher than desired idle speed.
P1509 GMC More InformationNeed more information on how to fix the P1509 GMC code?
Get Access to Factory Service Manuals