Component Function Check

WARNING: This page is about a different car, the 2019 Nissan NV3500 HD, 2019 Nissan NV2500 HD, and 2019 Nissan NV1500. However, it is still accessible from the selected car via links, so may be relevant.

Whenever system's high and/or low side pressure is abnormal, diagnose using a manifold gauge. The marker above the gauge scale in the following tables indicates the standard (usual) pressure range. Since the standard (usual) pressure, however, differs from vehicle to vehicle, refer to Inspection (Ambient air temperature-to-operating pressure table).

Both High- and Low-pressure Sides are Too High

Gauge indication	Refrigerant cycle	Probable cause	Corrective action
Both high- and low-pressure sides are too high. Courtesy of NISSAN NORTH AMERICA, INC.	Pressure is reduced soon after water is splashed on condenser.	Excessive refrigerant charge in refrigeration cycle	Reduce refrigerant until specified pressure is obtained.
	Air suction by cooling fan is insufficient.	Insufficient condenser cooling performance Condenser fins are clogged. Improper fan rotation of cooling fan	Clean condenser. Check and repair cooling fan if necessary.
	Low-pressure pipe is not cold. When A/C compressor is stopped high-pressure value quickly drops by approximately 196 kPa (2 kg/cm ² , 28 psi). It then decreases gradually thereafter.	Poor heat exchange in condenser (After A/C compressor operation stops, high-pressure decreases too slowly.) Air in refrigeration cycle	Evacuate and recharge system.
	Engine tends to overheat.	Engine cooling systems malfunction.	Check and repair engine cooling system.
	An area of the low-pressure pipe is colder than areas near the evaporator outlet. Plates are sometimes covered with frost.	Excessive liquid refrigerant on low-pressure side Excessive refrigerant discharge flow Expansion valve is open a little compared with the specification. Improper expansion valve adjustment	Replace expansion valve. Refer to Removal and Installation - Front Expansion Valve .