Powertrain, generic · Auxiliary emission controls
P0489 EGR A Control Circuit Low
Check engine lightOn
EmissionsRelevant
Drive cycleRequired
Limp modeNo
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.
Likely causes
Harness chafed at the exhaust with short to ground
EGR valve winding shorted to its housing
Water or corrosion in the connector
Driver in the engine module
Symptoms
- Check engine light on
- EGR switched off
- Rough idle or stalling if the valve stays open
Repair estimate
DifficultyMediumDIY possible
Parts and labour€50–700
Time0.5–3 h
Typical range across vehicles; the real cost depends on what the testing finds.
Parts involved
egr valveegr valve actuatoregr wiringengine control module
Related codes
References: gsi.ext.gm.com, gsi.ext.gm.com, fordservicecontent.com, saabwisonline.com.