DTC P0703 [LF]: Notes

DTC P0703 (LF) DETECTION CONDITION AND POSSIBLE CAUSE

DTC P0703	Brake switch input circuit problem
DETECTION CONDITION	The PCM monitors changes in input voltage from the brake switch No. 1. If the PCM does not the voltage changes while alternately accelerating and decelerating 8 times, the PCM determines that the brake switch No. 1 circuit has a malfunction. Diagnostic support note This is a continuous monitor (CCM). The MIL 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 the first drive cycle. FREEZE FRAME DATA (Mode 2/Mode 12) is available. The DTC is stored in the PCM memory.
POSSIBLE CAUSE	Brake switch connector or terminals malfunction Open circuit or short to ground in brake switch No. 1 power supply circuit Short to ground in wiring harness between battery positive terminal and brake switch terminal B Brake switch No. 1 power supply circuit related fuse malfunction Open circuit in wiring harness between battery positive terminal and brake switch terminal B Short to ground in wiring harness between brake switch terminal D and PCM terminal 1AB PCM connector or terminals malfunction Short to power supply in wiring harness between brake switch terminal D and PCM terminal 1AB Open circuit in wiring harness between brake switch terminal D and PCM terminal 1AB Brake switch malfunction PCM malfunction
Courtesy of MAZDA MOTORS CORP.

DTC P0703

Brake switch input circuit problem

DETECTION CONDITION

The PCM monitors changes in input voltage from the brake switch No. 1. If the PCM does not the voltage changes while alternately accelerating and decelerating 8 times, the PCM determines that the brake switch No. 1 circuit has a malfunction.

Diagnostic support note

This is a continuous monitor (CCM).
The MIL 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 the first drive cycle.
FREEZE FRAME DATA (Mode 2/Mode 12) is available.
The DTC is stored in the PCM memory.

POSSIBLE CAUSE

Brake switch connector or terminals malfunction
Open circuit or short to ground in brake switch No. 1 power supply circuit
- Short to ground in wiring harness between battery positive terminal and brake switch terminal B
- Brake switch No. 1 power supply circuit related fuse malfunction
- Open circuit in wiring harness between battery positive terminal and brake switch terminal B
Short to ground in wiring harness between brake switch terminal D and PCM terminal 1AB
PCM connector or terminals malfunction
Short to power supply in wiring harness between brake switch terminal D and PCM terminal 1AB
Open circuit in wiring harness between brake switch terminal D and PCM terminal 1AB
Brake switch malfunction
PCM malfunction

Courtesy of MAZDA MOTORS CORP.