Nubira SX Hatchback L4-2.0L DOHC D-TEC MFI (1999)
Expansion Valve: Description and Operation
Expansion Valve
The expansion valve is located with the evaporator core, inside the heater/air distributor case under the instrument panel.
The expansion valve can fail in three different positions: open, closed, or restricted.
An expansion valve that fails in the open position will result in a noisy A/C compressor or no cooling. The cause can be a broken spring, a broken ball,
or excessive moisture in the A/C system. If the spring or the ball are found to be defective, replace the expansion valve. If excessive moisture is found in
the A/C system, recycle the refrigerant.
An expansion valve that fails in the closed position will result in low suction pressure and no cooling. This may be caused by a failed power dome or
excessive moisture in the A/C system. If the power dome on the expansion valve is found to be defective, replace the expansion valve. If excessive
moisture is found in the A/C system, recycle the refrigerant.
A restricted expansion valve will result in low suction pressure and no cooling. This may be caused by debris in the refrigerant system. If debris is
believed to be the cause, recycle the refrigerant, replace the expansion valve, and replace the receiver-dryer.
