P081FBrake Transmission Shift Interlock (BTSI) Signal Correlation
- Generic OBD-II code · Powertrain
- How the car detects it
- The brake transmission shift interlock (BTSI) is a solenoid or actuator that locks the selector in park until the brake pedal is pressed, as US rule FMVSS 114 requires. 'Signal correlation' is the plausibility check between the interlock command or feedback and its input signals – brake switch and selector position: for example the lock released without a brake signal, or still active although the brake is pressed. The selector then cannot leave park, or it moves without the brake and the safety function is missing. Electrical faults of the lock solenoid have their own codes P0928–P0931. No manufacturer document with P081F is available to us; a GM service update for the 2016 Malibu and 2016–17 Volt explains the part and the 'won't shift out of park' complaint. CARB may exempt such safety parts from monitoring.
- What you may notice
- Selector cannot be moved out of P
- Selector moves out of P without the brake
- Warning about brake or range
- Likely causes
- LikelyBrake lamp switch misadjusted or faulty
- PossibleInterlock solenoid or locking mechanism sticking
- PossibleWire or connector to the selector
- RareSelector module, control unit or software
- Repair
- Medium · Usually a job for a workshop.Typical cost: €50 – €500
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.