DTC P0403: Notes

DTC P0403 [AJ] DETECTION CONDITION AND POSSIBLE CAUSES

DTC P0403	EGR valve (stepper motor) circuit malfunction
DETECTION CONDITION	The PCM monitors the EGR valve control signal voltage and current. If the following conditions are met, the PCM determines there is an EGR control circuit problem. The PCM turns the EGR valve off, but the voltage of the EGR valve control signal remains low. The PCM turns the EGR valve on, but the current of the EGR valve control signal remains high. 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 is available. DTC is stored in the PCM memory.
POSSIBLE CAUSE	EGR valve malfunction Connector or terminal malfunction Short to power supply in wiring harness between EGR valve terminal E and PCM terminal 98 Short to power supply in wiring harness between EGR valve terminal A and PCM terminal 99 Short to power supply in wiring harness between EGR valve terminal B and PCM terminal 72 Short to power supply in wiring harness between EGR valve terminal F and PCM terminal 73 Short to ground circuit in wiring between EGR valve terminal E and PCM terminal 98 Short to ground circuit in wiring between EGR valve terminal A and PCM terminal 99 Short to ground circuit in wiring between EGR valve terminal B and PCM terminal 72 Short to ground circuit in wiring between EGR valve terminal F and PCM terminal 73 Open circuit in wiring between EGR valve terminal E and PCM terminal 98 Open circuit in wiring between EGR valve terminal A and PCM terminal 99 Open circuit in wiring between EGR valve terminal B and PCM terminal 72 Open circuit in wiring between EGR valve terminal F and PCM terminal 73 Open circuit in wiring between main relay terminal D and EGR valve terminal C Open circuit in wiring between main relay terminal D and EGR valve terminal D PCM malfunction
Courtesy of MAZDA MOTORS CORP.

DTC P0403

EGR valve (stepper motor) circuit malfunction

DETECTION CONDITION

The PCM monitors the EGR valve control signal voltage and current. If the following conditions are met, the PCM determines there is an EGR control circuit problem.
- The PCM turns the EGR valve off, but the voltage of the EGR valve control signal remains low.
- The PCM turns the EGR valve on, but the current of the EGR valve control signal remains high.

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 is available.
DTC is stored in the PCM memory.

POSSIBLE CAUSE

EGR valve malfunction
Connector or terminal malfunction
Short to power supply in wiring harness between EGR valve terminal E and PCM terminal 98
Short to power supply in wiring harness between EGR valve terminal A and PCM terminal 99
Short to power supply in wiring harness between EGR valve terminal B and PCM terminal 72
Short to power supply in wiring harness between EGR valve terminal F and PCM terminal 73
Short to ground circuit in wiring between EGR valve terminal E and PCM terminal 98
Short to ground circuit in wiring between EGR valve terminal A and PCM terminal 99
Short to ground circuit in wiring between EGR valve terminal B and PCM terminal 72
Short to ground circuit in wiring between EGR valve terminal F and PCM terminal 73
Open circuit in wiring between EGR valve terminal E and PCM terminal 98
Open circuit in wiring between EGR valve terminal A and PCM terminal 99
Open circuit in wiring between EGR valve terminal B and PCM terminal 72
Open circuit in wiring between EGR valve terminal F and PCM terminal 73
Open circuit in wiring between main relay terminal D and EGR valve terminal C
Open circuit in wiring between main relay terminal D and EGR valve terminal D
PCM malfunction

Courtesy of MAZDA MOTORS CORP.