DTC P0703-00; Brake Switch Input Circuit Problem: Notes

DTC P0703:00	Brake switch input circuit problem
DETECTION CONDITION	The brake switch does not switch even though the vehicle is stopped 8 times repeatedly from a vehicle speed of 30 km/h {19 mph} or more. Diagnostic support note This is a continuous monitor (CCM). The check engine light illuminates if the PCM detects the above malfunction condition in two consecutive drive cycles or in one drive cycle while the DTC for the same malfunction has been stored in the PCM. PENDING CODE is available if the PCM detects the above malfunction condition during first drive cycle. FREEZE FRAME DATA/Snapshot data is available. DTC is stored in the PCM memory.
FAIL-SAFE FUNCTION	Not applicable
POSSIBLE CAUSE	CAUTION: Inspect the brake switch with it installed to the brake pedal, otherwise the brake switch may not operate normally. If the brake switch is removed from the brake pedal, replace the brake switch with a new one. Brake switch connector or terminals malfunction Short to ground or open circuit in brake switch No. 1 power supply circuit: Short to ground in wiring harness between MAIN 200 A fuse and brake switch terminal A MAIN 200 A fuse and/or STOP 10 A fuse malfunction Open circuit in wiring harness between battery positive terminal and brake switch terminal A Short to ground in wiring harness between brake switch terminal D and PCM terminal 2G PCM connector or terminals malfunction Short to power supply in wiring harness between brake switch terminal D and PCM terminal 2G Open circuit in wiring harness between brake switch terminal D and PCM terminal 2G Brake switch No. 1 malfunction PCM malfunction

DTC P0703:00

Brake switch input circuit problem

DETECTION CONDITION

The brake switch does not switch even though the vehicle is stopped 8 times repeatedly from a vehicle speed of 30 km/h {19 mph} or more.

Diagnostic support note

This is a continuous monitor (CCM).
The check engine light illuminates if the PCM detects the above malfunction condition in two consecutive drive cycles or in one drive cycle while the DTC for the same malfunction has been stored in the PCM.
PENDING CODE is available if the PCM detects the above malfunction condition during first drive cycle.
FREEZE FRAME DATA/Snapshot data is available.
DTC is stored in the PCM memory.

FAIL-SAFE FUNCTION

Not applicable

POSSIBLE CAUSE

CAUTION:

Inspect the brake switch with it installed to the brake pedal, otherwise the brake switch may not operate normally. If the brake switch is removed from the brake pedal, replace the brake switch with a new one.

Brake switch connector or terminals malfunction
Short to ground or open circuit in brake switch No. 1 power supply circuit:
- Short to ground in wiring harness between MAIN 200 A fuse and brake switch terminal A
- MAIN 200 A fuse and/or STOP 10 A fuse malfunction
- Open circuit in wiring harness between battery positive terminal and brake switch terminal A
Short to ground in wiring harness between brake switch terminal D and PCM terminal 2G
PCM connector or terminals malfunction
Short to power supply in wiring harness between brake switch terminal D and PCM terminal 2G
Open circuit in wiring harness between brake switch terminal D and PCM terminal 2G
Brake switch No. 1 malfunction
PCM malfunction

Fig 1: Identifying Brake Switch Wiring Harness Side Connector Terminals

Courtesy of MAZDA MOTORS CORP.