C0784Trailer Brake Force Sensor Circuit Malfunction
- Generic OBD-II code · Chassis
- How the car detects it
- Searches for C0784 came up empty: the public code lists, the NHTSA bulletin index, GM's keyword table and the Saab and Mitsubishi indexes all miss it. The title points to the signal an integrated trailer brake controller uses to gauge how hard the driver is braking. Patents show the usual choices: a pressure transducer on the master cylinder, a pedal travel sensor or an accelerometer, whose proportional output sets the current to the trailer's electric brakes. Continental adds a gain optimiser that compares master cylinder pressure with measured deceleration, for example 0.5 g expected at 80 bar, and raises the trailer gain when the rig stops too weakly. Without a valid signal the controller can no longer scale trailer braking to the driver's demand.
- What you may notice
- Trailer brakes weak, delayed or not applied when the vehicle brakes
- Trailer brake warning message in the instrument cluster
- Likely causes
- LikelyOpen, shorted or corroded wiring or connector of the brake force or pressure signal
- PossibleBrake pressure transducer or deceleration sensor defective
- RareTrailer brake controller module faulty or wrongly configured
- Repair
- Medium · Usually a job for a workshop.Typical cost: €60 – €600
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.