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Test Description

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The numbers below refer to the step numbers on the diagnostic table.

  1. 2:  This step ensures that the primary HVAC system is functioning properly.
  2. 5:  If the condition does not occur when a heating request has been made then you must bypass the A/C compressor and cooling system diagnostic information.
Too Cold in Vehicle - Auxiliary (w/ sunroof)

Step Action Values Yes No
Schematic Reference:  HVAC Schematics  
DEFINITION: Auxiliary air temperature cannot be adjusted from one or both auxiliary controls or auxiliary heating is insufficient.
1 Did you review the HVAC operation and perform the necessary inspections? - Go to Step 2  Go to Diagnostic System Check - HVAC Systems - Automatic 
2 
IMPORTANT: The auxiliary HVAC control assembly operates independently of the HVAC control module to provide heated airflow through the auxiliary system.
Does the HVAC control module operate and provide sufficient heating?		 - Go to Step 3  Go to Too Cold in Vehicle 
3
  1. Turn ON the ignition, with the engine OFF.
  2. Place the A/C auxiliary blower motor switch in each speed position.
Does the auxiliary blower motor operate at all?		 - Go to Step 4  Go to Blower Motor Inoperative - Auxiliary (W/O Sunroof) Blower Motor Inoperative - Auxiliary (W/Sunroof or Heat Only) 
4 Does the auxiliary blower motor operate correctly for each speed position? - Go to Step 5  Go to Blower Motor Malfunction - Auxiliary (W/O Sunroof) Blower Motor Malfunction - Auxiliary (W/Sunroof or Heat Only) 
5  Inspect the cooling system for the following conditions:
  • A low coolant level
  • A loose or worn accessory drive belt
  • A leaking radiator or auxiliary heater hoses
  • A kinked radiator or auxiliary heater hoses
  • A missing radiator cap pressure seal
  • A leaking radiator cap

Did you find and correct the condition?		 - Go to Step 18  Go to Step 6 
6
  1. Start the engine.
  2. Place the blower motor switch in the OFF 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
  1. Turn ON the ignition, with the engine OFF.
  2. Observe the drive shaft of the auxiliary air temperature actuator.
  3. Adjust the auxiliary air temperature switch.
Does the auxiliary air temperature actuator drive shaft rotate at all?		 - Go to Step 8  Go to Step 9 
8 Inspect the auxiliary air temperature door and the auxiliary air temperature actuator for the following conditions:
  • Misaligned auxiliary air temperature actuator. Refer to AIR TEMPERATURE ACTUATORS - AUXILIARY .
  • Broken or binding linkages or auxiliary air temperature door
  • Obstruction that prevents the auxiliary air temperature door from operating within it's full range of motion
  • Missing seals to the auxiliary air temperature door
  • Misaligned seals to the auxiliary air temperature door

Did you find and correct the condition?		 - Go to Step 18  Go to HEATING SYSTEM PERFORMANCE
9 Test the ignition 3 voltage circuit of the auxiliary air temperature actuator for an open or a high resistance. Refer to CIRCUIT TESTING and WIRING REPAIRS .
Did you find and correct the condition?		 - Go to Step 18  Go to Step 10 
10 Test the ground circuit of the auxiliary air temperature actuator for an open. Refer to CIRCUIT TESTING and WIRING REPAIRS .
Did you find and correct the condition?		 - Go to Step 18  Go to Step 11 
11 Test the temperature door control circuit of the auxiliary air temperature actuator for an open, a high resistance, short to ground or short to voltage. Refer to CIRCUIT TESTING and WIRING REPAIRS .
Did you find and correct the condition?		 - Go to Step 18  Go to Step 12 
12
IMPORTANT: The auxiliary HVAC control assembly connector must be connected to correctly perform test.
  1. Turn ON the ignition, with the engine OFF.
  2. Measure the voltage from the auxiliary temperature door control circuit of the auxiliary air temperature actuator to a good ground.
  3. Adjust the auxiliary air temperature switch.
Does the voltage change and measure within the specified range?		 0-12 V Go to Step 13  Go to Step 15 
13 Inspect for poor connections at the harness connector of the auxiliary air temperature actuator. Refer to TESTING FOR INTERMITTENT AND POOR CONNECTIONS and CONNECTOR REPAIRS .
Did you find and correct the condition?		 - Go to Step 18  Go to Step 14 
14 Inspect the auxiliary air temperature actuator, door and any attaching linkage for binding or a condition that prevents drive shaft rotation
Did you find and correct the condition?		 - Go to Step 18  Go to Step 16 
15 Inspect for poor connections at the harness connector of the auxiliary HVAC control assembly. Refer to TESTING FOR INTERMITTENT AND POOR CONNECTIONS and CONNECTOR REPAIRS .
Did you find and correct the condition?		 - Go to Step 18  Go to Step 17 
16 Replace the auxiliary air temperature actuator. Refer to AIR TEMPERATURE ACTUATORS - AUXILIARY .
Did you complete the replacement?		 - Go to Step 18  -
17 Replace the auxiliary HVAC control assembly. Refer to HVAC Control Assembly Replacement - Front Auxiliary .
Did you complete the replacement?		 - Go to Step 18  -
18 Operate the system in order to verify the repair.
Did you correct the condition?		 - System OK Go to Step 2 
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