Exhaust Brake Input Circuit
The exhaust brake activation input - typically from a stalk lever, brake pedal switch, or vehicle bus message - shows a circuit fault. The ECU cannot accept a request to engage the exhaust brake, which limits engine braking on heavy vehicles.
Affected components
- Exhaust brake request switch
- Exhaust brake actuator
Common causes
- High likelihood: Open in switch circuit
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.