EGR Cooler Performance
The EGR cooler does not lower exhaust gas temperature as expected — typically internal coolant fouling, a partial blockage, or a cracked cooler that mixes coolant with exhaust gas.
Affected components
- Egr cooler
- Egr temperature sensor
Common causes
- High likelihood: Cooler internally clogged with soot
- Medium likelihood: Cooler cracked, coolant entering exhaust
Possible symptoms
- Check engine light on
- Pinging or knocking under load
- Power loss and hesitation
- Possible rough idle
- Failed emissions inspection (NOx)
Diagnostic notes
- The malfunction indicator lamp may illuminate
- This code can affect emissions
- A drive cycle may be required after repair
Sources
Diagnostic information is provided for reference only. Confirm the code with a compatible scan tool and follow the vehicle manufacturer's service procedures before replacing components.