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Too Cold in Vehicle

WARNING: This page is about a different car, the 2007 GMC Sierra and 2007 Chevrolet Silverado. However, it is still accessible from the selected car via links, so may be relevant.
Too Cold in Vehicle

Step Action Yes No
Schematic Reference: HVAC Schematics 
Connector End View Reference: HVAC Connector End Views 
DEFINITION: The temperature cannot be adjusted, or the heating is insufficient.
1 Did you perform the Diagnostic System Check - Vehicle? Go to Step 2  Go to Diagnostic System Check - Vehicle
2
IMPORTANT: If during this diagnostic procedure the HVAC control module is disconnected a recalibration of actuators must be performed to avoid misdiagnosis.
  1. Recalibrate actuators. Refer to Actuator Recalibration .
  2. Turn ON the ignition, with the engine OFF.
  3. Observe the Diagnostic Trouble Code (DTC) List - Vehicle .
Does the scan tool display any DTC's?		 Go to Diagnostic Trouble Code (DTC) List - Vehicle Go to Step 3 
3
  1. Turn ON the ignition, with the engine OFF.
  2. Place the blower motor switch in each speed position.
Does the blower motor operate in any of the speed positions?		 Go to Step 4  Go to Blower Motor Inoperative 
4 Does the blower motor operate at the desired speed? Go to Step 5  Go to Blower Motor Malfunction 
5
  1. Place the mode switch in the PANEL position.
  2. Place the recirculation switch in the ON position.
  3. Observe the recirculation door.
  4. Place the recirculation switch in the OFF position.
Does the recirculation door move from the recirculation position to the outside air position?		 Go to Step 6  Go to Air Recirculation Malfunction 
6
  1. Start the engine.
  2. Place the mode switch in the Panel position.
  3. Place the A/C request switch in the OFF position.
Does the A/C compressor operate?		 Go to HVAC Compressor Clutch Does Not Disengage  Go to Step 7 
7 Perform the Heating Performance Diagnostic. Refer to Heating Performance Diagnostic .
Did you find and correct the condition?		 Go to Step 11  Go to Step 8 
8
  1. Turn ON the ignition, with the engine OFF.
  2. With a scan tool, observe the Left Mix Door Actual and the Right Mix Door Actual parameters in the Heating and Air Conditioning Door Positions data list.
  3. Place the left and right air temperature switches from the coldest position to the warmest position.
Does the Left Mix Door Actual and the Right Mix Door Actual parameters counts change?		 System OK Go to Step 9 
9 Inspect for poor connections at the harness connector of the HVAC control module. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs .
Did you find and correct the condition?		 Go to Step 11  Go to Step 10 
10 Replace the HVAC control module. Refer to Control Module References for replacement, setup, and programming.
Did you complete the replacement?		 Go to Step 11  -
11 Operate the system in order to verify the repair.
Did you correct the condition?		 System OK Go to Step 2 
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