Hello. Thanks for the donation. Much appreciated
sounds like you may have a slight leak in the system somewhere or the PCM is not getting a signal it requires to activate the A/C?
The A/C refrigerant system is a clutch cycling orifice tube type. The system components are:
A/C condenser core
A/C evaporator core
Connecting refrigerant lines
The refrigeration system operation is controlled by the following:
Evaporator core orifice tube.
A/C cycling switch.
A/C compressor pressure relief valve.
A/C high pressure cutoff switch.
The refrigerant system incorporates an A/C compressor controlled by the powertrain control module (PCM) through an A/C clutch relay.
The A/C cycling switch senses evaporator core pressure to control A/C compressor operation.
An evaporator core orifice tube is installed in the condenser-to-evaporator line at the A/C condenser fitting to meter the liquid refrigerant into the evaporator core.
The A/C compressor clutch will only be engaged by the PCM if all of the following conditions are met:
The climate control assembly is set to a mode which provides an A/C request to the instrument cluster. This request is then transferred to the PCM through the CAN bus.
The A/C cycling switch is reading an acceptable low side refrigerant pressure.
The A/C high pressure cutoff switch is not open due to excessive pressure in the high side of the refrigerant system.
The A/C compressor relay is energized by the PCM.
The engine coolant temperature is not excessively high.
The PCM has not detected a wide open throttle (WOT) condition.
An A/C compressor pressure relief valve is installed in the compressor manifold and tube assembly to protect the refrigerant system against excessively high refrigerant pressures.
Sunday, July 18th, 2010 AT 5:45 PM