P0506 Code: Idle Control System RPM Lower Than Expected
P0506 means the engine is idling lower than the ECM’s target.
- Applies to
- All OBD-II vehicles (any make or model)
- Est. repair cost
- $40 – $300
- Time to fix
- 1-3 hours
What it means
Common causes are a carbon-clogged throttle body/IAC, a vacuum leak, or a dirty air intake. This is a generic OBD-II powertrain code defined in the SAE J2012 standard, so it applies to virtually any 1996-or-newer OBD-II vehicle — cars, trucks, and modern fuel-injected motorcycles — from any manufacturer (Toyota, Honda, Ford and the rest). Read it with any OBD-II scanner; the meaning is the same across brands, though the exact repair can vary by engine.
Symptoms
- Check engine light on
- Low or stumbling idle; occasional stall
- Rough idle
How to fix it
- 1
Clean intake and check for leaks
1. Clean the throttle body and idle-air passages. 2. Inspect for vacuum leaks. 3. Reset idle relearn if needed, then clear the code.
Frequently asked questions
Is P0506 serious?
Usually minor — it mainly causes a low/rough idle. Cleaning the throttle body and checking for leaks resolves most cases.
Last updated July 16, 2026
Guidance only — always consult a qualified professional or the official service manual before carrying out repairs.