Parts or components should not be replaced with reference to only a B0172 DTC. The vehicle service manual should be consulted for more information on possible causes of the fault, along with required testing.
B0172 code shows that location the body harness connector, located in and around the left hand kick panel area or inside the IP (consult a shop manual for location). Water can leak into the connector from clogged sunroof drains, A-pillar leaks, or windshield or cowling leaks.
The leak detection pump is part of the evaporative emissions system. This system tests the fuel system to make sure it is not leaking fuel vapors into the air. The system pulls a vacuum on the fuel system and holds it for a period of time.
Air Conditioning Pressure Sensor (ACP) Insufficient Pressure Change Each time the A/C clutch engages, the PCM is looking for a pressure change in the refrigerant. If the change in pressure is outside of the calibration the DTC will set. A/C system mechanical failure Open ACP or VREF circuit A/C sensor damaged A/C system electrical failure A/C clutch always engaged Verify A/C system function, including refrigerant charge.