P1509 GMC Code - Idle Speed High Idle Air Control System Not Responding
Quick Answer
With 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. Common causes include Faulty Idle Air Control (IAC), Idle Air Control Valve harness is open or shorted, Idle Air Control Valve circuit poor electrical connection. Severity is High - diagnose this code as soon as possible. Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.
- What it means
- P1509 GMC indicates Idle Speed High Idle Air Control System Not Responding.
- Common causes
- Common causes include Faulty Idle Air Control (IAC), Idle Air Control Valve harness is open or shorted, Idle Air Control Valve circuit poor electrical connection.
- Severity
- High - diagnose this code as soon as possible.
- Can I drive?
- Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.
Code P1509 GMC Description
What are the Possible Causes of the DTC P1509 GMC?
- Faulty Idle Air Control (IAC)
- Idle Air Control Valve harness is open or shorted
- Idle Air Control Valve circuit poor electrical connection
How to Fix the DTC P1509 GMC?
Review the 'Possible Causes' above and visually examine the corresponding wiring harness and connectors. Check for damaged components and inspect connector pins for signs of being broken, bent, pushed out, or corroded.
What is the Cost to Diagnose the Code?
Labor: 1.0
To diagnose the P1509 GMC code, it typically requires 1.0 hour of labor. Rates vary by location, vehicle, and shop. Many shops charge between $80–$150 per hour; dealerships and metro areas may be higher, independents may be lower.
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Frequently Asked Questions about P1509 GMC Code
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