Brake Light Switch, Implausible Information

P0702

Diagnosis information - PDK

Brake light switch, implausible information

Diagnostic conditions
The control unit initially tests internal function sequences when the ignition is switched on (terminal 15). If they are OK, all diagnosable outputs are then tested and any faults are stored.
- Ignition on
- No CAN bus fault

Possible fault causes
- Brake light switch faulty
- Brake light test switch faulty
- CAN bus faulty
- Fault in PSM control unit

Fault setting conditions
- Brake light switch and brake light test switch supply different information

Fault effects
- Transmission limp-home indication in instrument cluster