GM Service Manual Online
For 1990-2009 cars only
PCM/ECM -- A/C Disengage Reason: The scan tool displays the last reason the A/C compressor was disengaged.

PCM/ECM -- A/C Off For WOT : The scan tool displays Yes or No. Yes indicates that the powertrain control module (PCM)/engine control module (ECM) has disabled the A/C compressor because the TP sensor signal is at wide open throttle.

PCM/ECM -- A/C Pressure Disable : The scan tool displays Yes or No. Yes indicates that the PCM/ECM has disabled the A/C compressor due to excessive refrigerant pressure.

PCM/ECM -- A/C High Side Pressure : The scan tool displays -103 to +3119 kPa( -14 to +452 psi). This parameter represents the A/C refrigerant pressure sensor voltage signal converted to pressure.

PCM/ECM -- A/C High Side Pressure : The scan tool displays 0.00-5.00 Volts. This parameter represents the A/C refrigerant pressure sensor signal.

PCM/ECM -- A/C Relay Command : The scan tool displays On or Off. Represents the PCM/ECM commanded state of the A/C compressor clutch relay control circuit. The A/C compressor clutch should be engaged when Commanded A/C displays On.

PCM/ECM -- A/C Relay Circuit History : The scan tool displays OK, Open, Short or Invalid State. This parameter indicates the state of the driver circuit for this device.

PCM/ECM -- A/C Request Signal : The scan tool displays Yes or No. The PCM/ECM uses the A/C request signal in order to determine if A/C compressor operation is being requested by the HVAC Control Module.

HVAC -- A/C Request: The scan tool displays Yes or No. This states that the A/C request is being made by the HVAC control module.

HVAC -- Recirculation Dr. Position: This data indicates the actual door position.

HVAC -- Recirculation Dr. Motor Command: This data indicates the value of the commanded door position.

HVAC -- Mode Dr. Position: This data indicates the actual door position.

HVAC -- Mode Dr. Motor Command: This data indicates the value of the commanded door position.

HVAC -- Defrost Dr. Position: This data indicates the actual door position.

HVAC -- Defrost Dr. Motor Command: This data indicates the value of the commanded door position.

HVAC -- Driver Temp Dr. Position: This data indicates the actual door position.

HVAC -- Driver Temp Dr. Motor Command: This data indicates the value of the commanded door position.

HVAC -- Psgr. Temp Dr. Position: This data indicates the actual door position.

HVAC -- Psgr. Temp Dr. Motor Command: This data indicates the value of the commanded door position.

HVAC -- Aux Mode Dr. Position: This data indicates the actual door position.

HVAC -- Aux Mode Dr. Motor Command: This data indicates the value of the commanded door position.

HVAC -- Aux Temp Dr. Position: This data indicates the actual door position.

HVAC -- Aux Temp Dr. Motor Command: This data indicates the value of the commanded door position.

HVAC -- Evaporator Temp Sensor: The scan tool displays 0-255 counts.

HVAC -- Evaporator Sensor: The scan tool displays -40 to +215°C (-40 to +420°F). The output of the A/C low side thermistor.

HVAC -- Mode Status (Display: Recirc/Vent/Mix-Blend/Floor/Bi-Level/Defrost): This data indicates the mode selection knob position.

HVAC -- A/C LED: The scan tool displays on or off. This is the status of the LED.

HVAC -- Rear Defrost LED: The scan tool displays on or off. This is the status of the LED.

HVAC -- Driver Heated Seat Status: The scan tool displays Off/Low Heat/High Heat. This is the status of the heated seat switch.

HVAC -- Passenger Heated Seat Status: The scan tool displays Off/Low Heat/High Heat. This is the status of the heated seat switch.

HVAC -- Blower Motor Switch Position: The scan tool displays Off/On But Not High Blower/On and High Blower. This is the status of the Blower Motor switch Position.

HVAC -- Aux. Blower Motor Speed Command: The scan tool displays 0-255 counts. This is the auxiliary blower motor commanded speed.

HVAC -- Aux. Blower Motor Switch Position: The scan tool displays Aux/Off/1/2/3/4. This is the status of the Auxiliary Blower Motor switch Position.

HVAC -- Aux. Blower Motor Speed: The scan tool displays 0-255 counts. This is the actual status of the Auxiliary Blower Motor speed.