OBD2 Car ScannerWhat does P0508 mean?
P0508 stands for Idle Air Control System Circuit Low. The engine computer has found a problem with vehicle speed signals, idle control or another sensor input.
Powertrain codes cover the engine, transmission and emissions. When the car's computer sees a reading outside its normal range, it stores this code and may turn on a warning light on the dashboard.
Common causes
- Faulty vehicle speed sensor
- Dirty throttle body or idle air control valve
- Faulty switch or sensor
- Damaged wiring or connector
What to do
- Read all stored and pending codes with a scanner. Several codes together often point to one cause.
- Note the freeze frame data (speed, temperature, load) recorded when the code was set.
- Inspect the wiring and connectors of the part named in the code for damage, corrosion or looseness.
- Fix the most likely and cheapest cause first, then clear the code and drive to see if it comes back.
Read this code from your own car
Plug in a cheap ELM327 adapter and the app shows every fault code, what it means and how to fix it.
Frequently asked questions
What does P0508 mean?
P0508 means “Idle Air Control System Circuit Low”. It belongs to the speed, idle control and inputs group: The engine computer has found a problem with vehicle speed signals, idle control or another sensor input.
Is it safe to drive with P0508?
You can usually drive carefully for a short time, but fix it soon to avoid further damage or higher fuel use.
How do I clear P0508?
Fix the cause, then clear the code with an OBD2 scanner or app. If the fault is still there, the code will come back.
Related codes
- P0504Brake Switch A/B Correlation
- P0505Idle Control System Malfunction
- P0506Idle Control System RPM Lower Than Expected
- P0507Idle Control System RPM Higher Than Expected
- P0509Idle Air Control System Circuit High
- P050ACold Start Idle Air Control System Performance
- P050BCold Start Ignition Timing Performance
- P050CCold Start Engine Coolant Temperature Performance
Code meanings can vary by manufacturer. This page is general guidance, not a repair manual. Always confirm the cause before replacing parts.