DTC P0403:00: Notes

DTC P0403:00	EGR control circuit problem
DETECTION CONDITION	The PCM monitors the input voltage from EGR valve. If the voltage remains low or high, the PCM determines that the EGR valve circuit has a malfunction. 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 (Mode 2)/Snapshot data is available. The DTC is stored in the PCM memory.
FAIL-SAFE FUNCTION	-
POSSIBLE CAUSE	EGR valve connector or terminals malfunction Short to ground or open circuit in EGR valve power supply circuit Short to ground in wiring harness between the following terminals: ENG BAR 15 A fuse-EGR valve terminal C ENG BAR 15 A fuse-EGR valve terminal D ENG BAR 15 A fuse malfunction Open circuit in wiring harness between the following terminals: Main relay terminal C-EGR valve terminal C Main relay terminal C-EGR valve terminal D EGR valve malfunction Short to ground in wiring harness between the following terminals: EGR valve terminal E-PCM terminal 2AX EGR valve terminal A-PCM terminal 2BA EGR valve terminal B-PCM terminal 2AT EGR valve terminal F-PCM terminal 2AW PCM connector or terminals malfunction Short to power supply in wiring harness between the following terminals: EGR valve terminal E-PCM terminal 2AX EGR valve terminal A-PCM terminal 2BA EGR valve terminal B-PCM terminal 2AT EGR valve terminal F-PCM terminal 2AW Open circuit in wiring harness between the following terminals: EGR valve terminal E-PCM terminal 2AX EGR valve terminal A-PCM terminal 2BA EGR valve terminal B-PCM terminal 2AT EGR valve terminal F-PCM terminal 2AW PCM malfunction
Courtesy of MAZDA MOTORS CORP.