P0489EGR A Control Circuit Low
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- 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. P0489 means the drive circuit of EGR valve A – solenoid, stepper or DC motor – is shorted to ground. GM's Duramax LML sets it at 0.5 Ω or less to ground for 3 s, GM's 2016 diesels after 96 of 120 samples, Ford diesels after 0.35 s, Saab's 2.0 TiD likewise – MIL after two trips. The valve is usually switched off; with low-side control a short to ground can keep it energised and open, causing rough idle or stalling.
- What you may notice
- Check engine light on
- EGR switched off
- Rough idle or stalling if the valve stays open
- Likely causes
- LikelyHarness chafed at the exhaust with short to ground
- PossibleEGR valve winding shorted to its housing
- PossibleWater or corrosion in the connector
- RareDriver in the engine module
- 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: €50 – €700
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.