P0509
Idle Air Control System Circuit High
P0509 is an OBD-II diagnostic trouble code meaning: Idle Air Control System Circuit High. Common causes: idle air speed sensor (iac) malfunction, open or short circuit in wiring harness. Estimated repair cost: $33–111.
Symptoms
- Unstable idle
- Floating engine speed
- Engine stalls at idle
- Increased fuel consumption
Causes
- Idle air speed sensor (IAC) malfunction
- Open or short circuit in wiring harness
- Poor contact in connectors
- ECU malfunction
- Throttle valve contamination
How to Fix
- Check the status of the idle air speed sensor (IAC)
- Inspect the wiring harness for damage
- Check contacts in connectors
- Clean throttle body
- If necessary, replace the idle speed sensor
Related codes
Error P0509 by Vehicle Brand
FAQ
What does the P0509 code mean?
P0509 is an OBD-II diagnostic trouble code that indicates: Idle Air Control System Circuit High
What causes a P0509 error code?
The most common causes of P0509 include: Idle air speed sensor (IAC) malfunction; Open or short circuit in wiring harness; Poor contact in connectors; ECU malfunction.
How do I fix a P0509 diagnostic trouble code?
To fix P0509: Check the status of the idle air speed sensor (IAC). Inspect the wiring harness for damage. Check contacts in connectors. For a complete diagnosis, use an OBD-II scanner.
Is it safe to drive with P0509?
Limited driving only, diagnose soon
How much does it cost to fix P0509?
The estimated repair cost for P0509 is $33–111. Actual cost depends on your vehicle, location, and labor rates.
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