P081F — Brake Transmission Shift Interlock (BTSI) Signal Correlation
The Brake Transmission Shift Interlock prevents shifting out of Park unless the brake pedal is pressed. The TCM compares the brake-pedal input to the BTSI solenoid command and detects an inconsistency — for example shift permitted while brake not pressed, or interlock active while brake is pressed.
General code reference. Confirm the definition and diagnostic procedure for your vehicle's year, model and engine. A stored code alone does not identify a failed part.
Affected components
- Btsi solenoid
- Brake pedal switch
Possible causes to check
These are possible checks, not a ranked diagnosis. Follow the vehicle manufacturer's test procedure before replacing parts.
- Stuck brake pedal switch
- Mis-adjusted BTSI mechanism
Possible symptoms
- Check engine or transmission warning light on
- Harsh, delayed, or missing shifts
- Possible limp mode (locked in one gear)
- Slipping or shuddering during gear changes
Diagnostic notes
- The malfunction indicator lamp may illuminate
Sources
Check each reference's vehicle and model-year scope. General background links do not establish which fault is most likely on your vehicle.
Diagnostic information is provided for reference only. Confirm the code with a compatible scan tool and follow the vehicle manufacturer's service procedures before replacing components.