What does it mean?
C1116 is a Chassis (ABS, traction control, steering) fault code. It indicates: Stop Lamp Switch . This is a standardised OBD-II code. The technical definition is the same regardless of the make or model of vehicle, although specific causes and symptoms can vary between vehicles.
Symptoms
- Brake lights stay on all the time, or do not light at all
- ABS, stability control and sometimes cruise control warnings appear
- Cruise control will not set or cancels immediately
- Shifter will not release from Park on vehicles with a brake interlock
- Engine stop and start system stops working
- Battery drains overnight when the lamps remain lit
Likely causes
- Brake light switch out of adjustment after pedal or carpet work
- Crumbled or missing pedal stop pad so the switch never releases
- Worn switch contacts giving an intermittent or double signal
- Blown brake lamp fuse or corroded fuse holder
- Chafed, broken or shorted wiring at the pedal bracket where the harness flexes
- Corroded connector at the switch or at the rear lamp clusters
- Aftermarket alarm, trailer socket or LED conversion loading the circuit
How to fix it
- Watch the brake switch status in live data while an assistant presses and releases the pedal
- Check that the brake lamps follow the pedal exactly, with no delay or sticking
- Inspect the pedal stop pad and reset the switch adjustment to specification
- Check the brake lamp fuse and inspect the bulbs and sockets for corrosion
- Back probe the switch connector and test each output with a meter
- Inspect the harness at the pedal bracket for chafing and broken conductors
- Replace the switch if its contacts do not switch cleanly, then reprogramme or relearn if the vehicle requires it