Workshop Repair and Service Manuals GMC SIERRA
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HVAC

Fastener Tightening Specifications - 4WD Driveline Control      Fastener Tightening Specifications Application Specification Metric English Air Temperature Actuator Mounting Screw 1.6-Y 14-lb-in Mode Actuator Mounting Screw 1.6-Y 14-lb-in Overhead Console...
Fastener Tightening Specifications - 4WD Driveline Control      Fastener Tightening Specifications Application Specification Metric English Auxiliary Air Temperature Actuator Screws 1.6-Y 14-lb-in Auxiliary Blower Motor Processor Screws 1.6-Y 14-lb-in...
Air Delivery Description and Operation      The air delivery description and operation is divided into 7areas: HVAC Control ComponentsAir SpeedAuxiliary Air SpeedAir DeliveryAuxiliary Air DeliveryRecirculation OperationAutomatic OperationHVAC Control Components HVAC...
Air Delivery Description and Operation - part 2      As theactuator shaft rotates the changing position signal is sent to themodule. Once the position signal and the commanded value are thesame, the module changes the control signal to2.5-volts. Auxiliary Mode Actuator The...
Air Delivery Description and Operation - part 3      The blower motor control module is an interface between theHVAC control module and the blower motor. The blower motor speedcontrol, battery positive and ground circuits enable the controlmodule to operate. The HVAC control...
Air Delivery Description and Operation - part 4      The motor moves the mode door tothe desired position. Front Defrost When defrost is selected, the A/C compressor is activated.The A/C compressor clutch will engage when ambient temperatures areabove 3°C (38 F). The blower...
Air Delivery Description and Operation - part 5      Inside Air Temperature SensorAmbient Air Temperature SensorLower Left Air Temperature SensorLower Right Air Temperature SensorUpper Left Air Temperature SensorUpper Right Air Temperature SensorRegulate blower motor...
Air Temperature Description and Operation      The air temperature controls are divided into 7 areas: HVAC Control ComponentsHeating and A/C OperationAuxiliary Heating and A/C OperationAutomatic OperationAuxiliary Automatic OperationEngine Coolant A/C CycleHVAC Control...
Air Temperature Description and Operation - part 2      As the actuator shaft rotates the changing position signal issent to the module. Once the position signal and the commanded value are the same,the module changes the control signal to 2.5-volts. Auxiliary Air Temperature...
Air Temperature Description and Operation - part 3      The ambient air temperature sensor mounts underhood and can be affected by city traffic,by idling, and by restarting a hot engine. Therefore, the HVAC control module filtersthe value of the ambient air temperature sensor for...
Air Temperature Description and Operation - part 4      This value will not be displayedon the scan tool. The default action ensures that the HVAC system can adjust the insideair temperature near the desired temperature until the condition is fixed. The scantool parameter for the...
Air Temperature Description and Operation - part 5      The following conditions must be met in order for the A/C compressor clutch to turnON if they are not all met and an A/C request is made the LED on the A/C switch willflash: Ambient air temperature above 7°C (45°F)The...
Air Temperature Description and Operation - part 6      To place the auxiliary HVAC system in Automatic mode, the following is required: The auxiliary blower motor switch on the auxiliary HVAC control assembly must be inthe Auto position.The auxiliary mode switch on the auxiliary...
Sensor Resistance Table      Sensor Resistance Table Temperature Ambient Air Temp Sensor or Evaporator Temp Sensor Inside Air Temp Sensor (Front or Rear) Front Upper Duct Temp Sensors Heater Duct (Lower Air Temp) Sensors, Air Temperature Sensor-...
HVAC System Control Module Programming and Setup      Each of the following service procedures may requireprogramming or setup procedures to be performed on the HVAC controlmodule or HVAC actuators. HVAC Control Module Replacement If the HVAC control module is replaced it must be...
Drilling Holes into the Air Conditioning and Heater Case Module Caution      Caution:Extreme care must be taken when drilling into the air conditioning and heater casemodule. Misalignment of the hole can cause damage to the air conditioning evaporatoror temperature door requiring replacement of these...
Afterblow Enabling      The afterblow mode can be enabled using the scan tool. Theafterblow mode allows the blower motor to operate after the enginehas been turned off. This operation of the blower motor dries theevaporator core, which reduces the...
Air Temperature Description and Operation      The air temperature controls are divided into four areas: HVAC Control ComponentsHeating and A/C OperationEngine CoolantA/C CycleHVAC Control Components HVAC Control Module The HVAC control module is a class-2 device that...
Air Temperature Description and Operation - part 2      Heating and A/C Operation The purpose of the heating and A/C system is to provide heated and cooled air to theinterior of the vehicle. The A/C system will also remove humidity from the interiorand reduce windshield fogging....
Air Temperature Description and Operation - part 3      The ambient air temperature is less than 4°C (40°F).The evaporator temperature is less than 3°C (38°F).The throttle position is 100%.The A/C high side pressure is more than 2957-kPa (429-psi).The engine coolant temperature...
Air Delivery Description and Operation      The air delivery controls are divided into four areas: HVAC Control ComponentsAir SpeedAir DeliveryRecirculation OperationHVAC Control Components HVAC Control Module The HVAC control module is a class-2 device thatinterfaces...
Air Delivery Description and Operation - part 2      The HVAC control module sends differentsignals to the mode door actuator through the mode door controlcircuit. Zero volts drives the actuator in one direction while5-volts moves the actuator in the opposite direction.When the...
Temperature Valve Actuator Replacement - Right Side      Temperature Valve Actuator Replacement - Right Side Callout Component Name Caution:In order to avoid actuator damage, DO NOT apply power to theactuator when it is not installed in the HVAC module. Preliminary...
Temperature Valve Actuator Replacement - Left Side      Temperature Valve Actuator Replacement - Left Side Callout Component Name Caution:In order to avoid actuator damage, DO NOT apply power to theactuator when it is not installed in the HVAC module. Preliminary...