Both High- and Low-pressure Sides are Too Low

WARNING: This page is about a different car, the 2007 Nissan Pathfinder. However, it is still accessible from the selected car via links, so may be relevant.

PRESSURE DIAGNOSTIC CHART - BOTH HIGH AND LOW PRESSURE SIDES TOO LOW

Refrigerant cycle	Probable cause	Corrective action
There is a big temperature difference between liquid tank outlet and inlet. Outlet temperature is extremely low. Liquid tank inlet and expansion valve are frosted.	Liquid tank inside is slightly clogged.	Replace liquid tank. Check oil for contamination.
Temperature of expansion valve inlet is extremely low as compared with areas near liquid tank. Expansion valve inlet may be frosted. Temperature difference occurs somewhere in high-pressure side.	High-pressure pipe located between liquid tank and expansion valve is clogged.	Check and repair malfunctioning parts. Check oil for contamination.
Expansion valve and liquid tank are warm or only cool when touched.	Low refrigerant charge. ↓ Leaking fittings or components.	Check refrigerant system for leaks. Refer to "CHECKING FOR REFRIGERANT LEAKS ".
There is a big temperature difference between expansion valve inlet and outlet while the valve itself is frosted.	Expansion valve closes a little compared with the specification. ↓ Improper expansion valve adjustment. Malfunctioning expansion valve. Outlet and inlet may be clogged.	Remove foreign particles by using compressed air. Check oil for contamination.
An area of the low-pressure pipe is colder than areas near the evaporator outlet.	Low-pressure pipe is clogged or crushed.	Check and repair malfunctioning parts. Check oil for contamination.
Air flow volume is too low.	Evaporator is frozen.	Check intake sensor circuit. Refer to "INTAKE SENSOR CIRCUIT ". Replace compressor. Repair evaporator fins. Replace evaporator. Refer to "FRONT BLOWER MOTOR CIRCUIT ".