DTC P0504-2B: Brake Switch "A"/"B" Signal Cross Coupled [11/2022 - ]: Description
WARNING: This page is about a different car, the 2025 Toyota Corolla Cross, 2024 Toyota Corolla Cross, and 2023 Toyota Corolla Cross. However, it is still accessible from the selected car via links, so may be relevant.
The stop light switch assembly is a duplex system that transmits two signals: STP and ST1-. These two signals are used by the hybrid vehicle control ECU to monitor whether or not the brake system is working properly. If the signals, which indicate the brake pedal is being depressed and released, are detected simultaneously, the hybrid vehicle control ECU interprets this as a malfunction in the stop light switch assembly and stores this DTC.
HINT:
The normal signal conditions are as shown in the table below.
| Signal (hybrid vehicle control ECU Terminal) | Brake Pedal Released | In Transition | Brake Pedal Depressed |
|---|---|---|---|
| STP | OFF | ON | ON |
| ST1- | ON | ON | OFF |
- [OFF] denotes ground potential.
- [ON] denotes auxiliary battery potential (+B).
On the GTS, Data List item Stop Light SW is ON when the brake pedal is depressed.
| DTC No. | Detection Item | DTC Detection Condition | Trouble Area | MIL | Warning Indicate | Note |
|---|---|---|---|---|---|---|
| P0504-2B | Brake Switch "A"/"B" Signal Cross Coupled | Conditions (a) and (b) are met for 0.5 seconds or more (1 trip detection logic): (a) Ignition switch ON (b) STP signal OFF when ST1- signal OFF |
|
Does not come on | Master Warning: Does not come on |
SAE Code: P0504 |