Engine and gearbox (P)
P0506: Idle control system low RPM
This code indicates that the engine's idle speed is lower than expected. The engine control module is unable to maintain the correct idle speed.
Checked by a licensed car technician · last reviewed 29 September 2026
Symptoms
- Rough idle
- Engine stalling
- Low idle RPM
- Check engine light on
Common causes
- Vacuum leak
- Dirty throttle body
- Faulty idle air control valve
- Intake manifold gasket leak
How to check it yourself
- Inspect for vacuum leaks
- Clean the throttle body
- Check the idle air control valve
- Inspect intake manifold gasket
Can I keep driving?
The car can be driven, but stalling may occur, especially at stops.
General guidance, not a professional inspection. Confirm faults with measurements before buying parts, and use a qualified mechanic for brakes, steering, fuel leaks, airbags, and other safety-critical work. Terms and disclaimer