C05D7Brake Transmission Shift Interlock (BTSI) Control Circuit
- Generic OBD-II code · Chassis
- How the car detects it
- Covers the output that drives the brake transmission shift interlock, the solenoid that keeps the selector in park until the brake pedal is pressed. In the US, FMVSS 114 has required this lock since 1 September 2010 on vehicles up to 4,536 kg fitted with an automatic gearbox and a park position. A patent by Pontiac Coil shows the usual layout: a spring holds a blocking pin in the locked position, and a transistor energizes the coil only with ignition on and brake switch closed, so the system fails locked. The code points to the driver stage, wiring or coil. No manufacturer publishes C05D7; Ram logs P0928-00 for an internal BTSI fault in its rotary shifter. P081F is the signal correlation counterpart.
- What you may notice
- Selector cannot be moved out of park despite pressing the brake
- Selector leaves park without the brake applied
- No clicking of the interlock when the brake is pressed
- Likely causes
- LikelyInterlock solenoid coil open or shorted
- PossibleDamaged wiring or corroded connector at the shifter
- PossibleDriver stage in the shifter or body module faulty
- RareBrake light switch signal missing, so the lock is never released
- Repair
- Medium · Often possible to do yourself.Typical cost: €60 – €700
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.