What does it mean?
B1306 is a Body (airbags, seat belts, body electronics) fault code. It indicates: Brake pedal signal fault .
Symptoms
- Brake lamps stay on permanently, do not come on, or flicker
- Cruise control will not engage or cancels by itself
- Shift interlock may prevent moving the selector out of Park
- Push-button start may refuse to start the engine because the brake signal is required
- Stability control and automatic stop-start functions disabled
Likely causes
- Misadjusted or failed brake pedal (stop lamp) switch, by far the most common cause
- Bent pedal bracket or a switch pushed out of its retainer so the plunger never releases
- Corroded connector at the brake switch above the pedal
- Short or open in the wiring between the switch and the body or engine module
- Blown stop lamp fuse
- The two redundant switch contacts disagreeing, so the module rejects the signal
- Module input stage failure
How to fix it
- Watch the brake pedal switch state in live data while pressing and releasing the pedal
- Inspect the switch adjustment and the pedal bracket, then refit or readjust to specification
- Check the stop lamp fuse and the switch connector for corrosion
- Measure both switch contacts with a multimeter and confirm correct open and closed behaviour
- Check the wiring between the switch and the modules for an open or a short
- Replace the brake pedal switch when the contacts do not change state cleanly
- Clear codes, then verify brake lamps, cruise control and shift interlock all work correctly