Exhaust Brake Input Circuit Intermittent or Erratic
Same as P04D3 with intermittent or erratic signal. The exhaust control valve modulates exhaust backpressure or routing (EGR feed, sound, regen support); a malfunction shifts torque mapping and may trigger limp mode.
Affected components
- Exhaust brake request switch
- Exhaust brake wiring
Common causes
- High likelihood: Intermittent contact at connector
- Low likelihood: Connector with intermittent contact under vibration
- Low likelihood: Harness routed against vibrating component
Diagnostic notes
- The malfunction indicator lamp may illuminate
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.