P0609Control Module VSS Output B
- Generic OBD-II code · Powertrain
- How the car detects it
- Many engine or powertrain modules turn the raw wheel or output-shaft speed into a cleaned-up vehicle speed signal and pass it on through their own driver – a square-wave signal whose frequency rises with speed – to the instrument cluster, cruise control, radio or steering. P0609 concerns output B: the module compares the commanded driver state with the actual line state and reports a short to ground or voltage, an open circuit or an internal driver fault, as CARB requires for output components. Output B is a second output; which device hangs on it (cruise module, radio, body builder interface) depends on the wiring diagram. If the speed sensor itself fails, P0500–P0503 set instead. No manufacturer table available to us gives thresholds; GM lists the code in older vehicles. On modern cars speed is shared over CAN, so the code mainly affects older vehicles with a hard-wired speedometer signal.
- What you may notice
- Speed-dependent function of the receiver on output B disturbed
- Cruise control or add-on device without speed signal
- Often no noticeable driving symptom
- Likely causes
- LikelyShort or open in the output line B to the receiving module
- PossibleCorroded or spread connector pins at the module or receiver
- PossibleFaulty receiving module pulling the line to ground
- RareInternal driver fault in the module
- Repair
- Medium · Usually a job for a workshop.Typical cost: €80 – €600
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.