DTC P0645: A/C Relay Control Circuit: Notes

DTC P0645 CHART (MZI-3.7)

DTC P0645	A/C relay control circuit
DETECTION CONDITION	Monitors the A/C relay control circuit output from the PCM. The test fails when the PCM grounds the A/C relay control circuit, excessive current draw is detected on the A/C relay control circuit; or, with the A/C relay control circuit not grounded by the PCM, voltage is not detected on the A/C relay control circuit (the PCM expects to detect vehicle power voltage coming through the A/C relay coil to the A/C circuit).
POSSIBLE CAUSE	A/C relay connector or terminal malfunction Open circuit in wiring between main relay terminal No. 1 D and A/C relay terminal A Short to power supply between A/C relay terminal E and PCM terminal 1W Short to ground in wiring between A/C relay terminal E and PCM terminal 1W PCM connector or terminal malfunction Open circuit in wiring between A/C relay terminal E and PCM terminal 1W A/C relay malfunction PCM malfunction
Courtesy of MAZDA MOTORS CORP.