What P0489 means
Exhaust gas recirculation (EGR) routes part of the exhaust back into the intake to lower combustion temperature and NOx.
How the engine computer detects it
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 energized and open, causing rough idle or stalling.
Written from public technical sources and not yet checked by a mechanic. How we write these pages
Symptoms
- Check engine light on
- EGR switched off
- Rough idle or stalling if the valve stays open
Common causes
- Harness chafed at the exhaust with short to ground Most likely
- EGR valve winding shorted to its housing Possible
- Water or corrosion in the connector Possible
- Driver in the engine module Less likely
How to diagnose P0489
- Read every stored code with an OBD-II scanner. If misfire or fuel trim codes are there too, fix those first: they often cause this one.
- Inspect the parts involved: egr valve, egr valve actuator, egr wiring, engine control module.
- Work through the causes above from most to least likely, cheapest checks first.
- Clear the code and drive a full drive cycle to confirm the repair held.
Vehicles that report P0489 most
| Vehicle | Years | Reports | Share | Median miles |
|---|---|---|---|---|
| Chevrolet Volt | 2016–2018 | 4 | — |
Counts of owner complaints to the NHTSA that mention P0489 (4 in total), not failure rates: popular models get more complaints simply because more of them are on the road. Models with fewer than 3 complaints are left out.
Reading the code
- P
- Powertrain
- 0
- Generic (SAE) code
- 4
- Auxiliary emission controls
- 89
- Specific fault
Questions drivers ask
Can I drive with code P0489?
Usually yes for a short time, if the car drives normally, the temperature gauge reads normal and the check engine light is steady. If the light flashes, the engine loses power or overheats, or other warning lights come on, pull over and have it checked.
Will my car pass an emissions inspection with P0489?
Probably not in states that test vehicles with an OBD-II scan: an emissions-related code that keeps the check engine light on is usually an automatic fail. Rules differ by state and county, so check yours.
Will P0489 clear by itself?
The light can go off after several drive cycles without the fault, but the code returns if the cause is still there. After a repair, the readiness monitors need a full drive cycle before an inspection.
Can I fix P0489 myself?
Often yes, with an OBD-II scanner and basic tools. Difficulty: medium. Start with the cheapest checks before replacing expensive parts.
Often reported together
Codes that owners mention in the same NHTSA complaints as P0489. They can point to a shared cause, so it's worth checking them together.
- P0030HO2S Heater Control Circuit (Bank 1 Sensor 1)4 complaints
- P0031HO2S Heater Control Circuit Low (Bank 1 Sensor 1)4 complaints
- P0135O2 Sensor Heater Circuit Bank 1 Sensor 14 complaints
- P0443EVAP System Purge Control Valve A Circuit4 complaints
- P0458EVAP System Purge Control Valve A Circuit Low4 complaints
- P0597Thermostat Heater Control Circuit/Open4 complaints
This page is general information, not a substitute for a professional diagnosis. Repair costs are rough estimates for parts and labor and vary by vehicle and region.