Circuit Description
WARNING: This page is about a different car, the 2003 Lexus SC 430. However, it is still accessible from the selected car via links, so may be relevant.
NOTE:
Brake switch may also be referred to as stop light switch.
In this system, the signal of the stop light switch is used to judge whether the acceleration system is abnormal or not. The stop light switch has a duplex system (signals STP and ST1-) to memorize the abnormality when signals of depressing and releasing brake pedal are detected simultaneously. See BRAKE SWITCH OPERATION table. DTC P0504 will set when brake switch signal is not present. Possible causes are:
- Short in stop light switch signal circuit.
- Faulty stop light switch.
- Faulty ECM.
BRAKE SWITCH OPERATION
| Signal | Brake Pedal Released | In Transition | Brake Pedal Depressed |
|---|---|---|---|
| STP | OFF | ON | ON |
| ST1- | ON | ON | OFF |