Exhaust Pressure Control Valve A Stuck Open
Exhaust pressure control valve A is mechanically stuck open — backpressure cannot be raised, exhaust brake and DPF regen support fail.
Affected components
- Exhaust pressure regulator
Common causes
- High likelihood: Carbon buildup or broken return spring
- Low likelihood: Carbon or debris buildup preventing free movement
- Low likelihood: Component wear with age - mechanical play
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.