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.
Affected components
- Btsi solenoid
- Brake pedal switch
Common causes
- High likelihood: Stuck brake pedal switch
- Medium likelihood: 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
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.