P0488EGR Throttle Control Circuit A Range/Performance
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Can trigger limp mode
- Needs a drive cycle to confirm a fix
- How the car detects it
- Exhaust gas recirculation (EGR) routes part of the exhaust back into the intake to lower combustion temperature and NOx. The EGR throttle is a regulating flap ahead of the intake manifold on diesels: by closing partly it lowers manifold pressure below exhaust back pressure so that enough exhaust is recirculated, and it also helps filter regeneration and shuts off air at engine stop. It is usually a DC motor with position sensor. GM and Ford report this flap under P02E0 ff; no manufacturer document available to us uses this code. P0488 is its function check: the actual position reported by the sensor deviates from the target for too long, or the position signal is implausible – typically a coked, stiff flap or a broken gear. The flap then goes to its rest position or the engine enters limp mode, and the EGR rate cannot be controlled.
- What you may notice
- Check engine light on
- Loss of power or limp mode possible
- Shaking when the engine is switched off
- Filter regeneration does not complete
- Likely causes
- LikelyFlap coked by soot and oil mist (EGR plus crankcase ventilation)
- PossibleActuator gear or motor worn or broken
- PossiblePosition sensor in the flap faulty or implausible
- RareCorrosion on flap or housing
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Medium · Often possible to do yourself.Typical cost: €80 – €600
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.