DTC C0040-64: Brake Switch [DSC HU/Cm]: Outline
WARNING: This page is about a different car, the 2020 Mazda CX-30. However, it is still accessible from the selected car via links, so may be relevant.
| System malfunction location |
Brake switch |
| Detection condition |
NOTE:
- There are 2 types of brake switch signals as follows.
- Brake switch No. 1 signal received from electrical supply unit (ESU)
- Brake switch No. 2 signal received via CAN communication going through body control module (BCM) from PCM
- The DSC HU/CM detects any of the following conditions.
- While driving at vehicle speed exceeding 20 km/h {12 mph}, brake switch No. 1 signal is on for a continuous 6 min or more
- While driving at vehicle speed exceeding 40 km/h {25 mph}, brake switch No. 1 signal does not change from off to on even though there are 4 instances of vehicle speed decelerating to less than 3 km/h {2 mph}.
- Brake light switch No. 1 signal does not change from off to on even though brake fluid pressure sensor signal reaches specification
|
| Fail-safe |
Refer to "DTC Table" and "Fail-safe Function Malfunction Contents Table". (See DTC TABLE [DSC HU/CM (US)] .) |
| Possible cause |
- Brake switch connector or terminal malfunction
- Brake switch malfunction
- Short to ground or open circuit in brake switch power supply circuit
- Electrical supply unit (ESU) connector or terminals malfunction
- Short to power supply in brake switch signal circuit
- Short to ground in brake switch signal circuit
- Open circuit in brake switch signal circuit
- DSC HU/CM connector or terminals malfunction
- Short to ground in electrical supply unit (ESU) brake signal circuit
- Short to power supply in electrical supply unit (ESU) brake signal circuit
- Open circuit in electrical supply unit (ESU) brake signal circuit
- Electrical supply unit (ESU) malfunction
- DSC HU/CM malfunction
|
 Courtesy of MAZDA MOTORS CORP.
|