What does it mean?
C1425 is a Chassis (ABS, traction control, steering) fault code. It indicates: Open in Stop Light Switch Circuit .
Symptoms
- Brake lights do not work, or work only intermittently
- ABS and stability control warning lamps illuminate
- Cruise control will not set, or will not cancel when the pedal is pressed
- Selector cannot be moved out of Park on vehicles with a shift interlock
- Auto hold, hill hold and stop-start functions become unavailable
Likely causes
- Failed or badly adjusted brake light switch whose contacts no longer close
- Broken or crumbled pedal striker pad, letting the switch plunger stay extended
- Blown stop lamp fuse or an open feed to the switch
- Broken or chafed wire between the switch and the ABS/stability module
- Corroded, loose or spread terminals in the switch connector
- Poor ground or a bad body connector in the stop lamp circuit
- Rarely, a failed input circuit inside the control module
How to fix it
- Check the stop lamp fuse and the brake bulbs first
- Watch the brake switch parameter on a scan tool while an assistant presses the pedal
- Inspect switch adjustment and the pedal striker pad; a missing pad is a common cause
- Backprobe the switch connector for supply voltage and for a switched output when the pedal moves
- Test continuity of the signal wire from the switch to the module connector
- Check the circuit ground and any shared body connector for corrosion
- Adjust or replace the switch, clear the code and confirm the parameter changes state during a road test