EGR Cooler Bypass Control Stuck Open Bank 1
The EGR cooler bypass valve on bank 1 is mechanically stuck in the open (bypassing) position - EGR always bypasses the cooler, gas reaches the intake hotter than designed.
Affected components
- Egr cooler bypass valve b1
Common causes
- High likelihood: Valve stuck open
- Low likelihood: Carbon or debris buildup preventing free movement
- Low likelihood: Component wear with age - mechanical play
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
Related codes
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.