Idle control
P0505
Idle Air Control System
The engine is idling faster or slower than the computer is asking for.
Fine to drive
Can I keep driving? Yes, in most cases. It won't hurt the car in the short term, but get it fixed. A check engine light that's already on can't warn you about a new problem. It's safe to drive. A low idle can stall at stops. A high idle makes the car creep forward more.
Common causes
- A dirty throttle body
- A vacuum leak
- A sticking idle air control valve on older cars
- A throttle body that needs relearning after a battery change
Listed roughly from most to least likely. The same code can have different causes on different cars.
What to do
- Have the throttle body cleaned.
- Check the vacuum hoses for leaks.
- Ask for an idle relearn if the battery was recently disconnected.
General guidance. Your owner's manual wins. If a red warning light is on or the car drives differently, stop safely and get help.
Related codes
- P0506Idle Air Control System RPM Lower Than Expected
- P0507Idle Air Control System RPM Higher Than Expected
Track this automatically in Tagwell Auto
Tagwell Auto keeps your car's service dates and mileage, so when a code shows up you know what was done last. With a Bluetooth reader for the car's diagnostic port (called OBD-II), the phone app can read the code itself.