P04D4
Exhaust Brake Input Circuit Range or Performance
Same as P04D3 with the signal in plausible range yet not matching expected behaviour - e.g. activation request without driver input or no response after a request.
Same as P04D3 with the signal in plausible range yet not matching expected behaviour - e.g. activation request without driver input or no response after a request.
Common causes
- high
Signal implausible against driver action or bus
One of the most commonly reported causes for this code — check this first.
Typical part cost: $130-500
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First things to check
- 1Confirm the code with a scan tool and check for additional related codes.
- 2Inspect the relevant sensors, wiring, and connectors for damage or corrosion.
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Related codes
See related trouble codes
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Frequently asked questions
What does P04D4 mean?
P04D4 means "Exhaust Brake Input Circuit Range or Performance". It is a generic OBD-II code that points to a fault in the auxiliary emission controls.
What are the most common causes of P04D4?
signal implausible against driver action or bus — these are the most commonly reported causes. Verify with a proper diagnosis before replacing parts, or use the Wrenchify app for a vehicle-specific diagnosis.
Can I keep driving with this code?
The vehicle is usually drivable for short distances, but the problem can worsen or affect emissions. Diagnose and repair as soon as practical. Use the Wrenchify app for a full diagnosis specific to your vehicle.
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