Schematic Reference: HVAC Schematics.

Connector End View Reference: Component Connector End Views.

DEFINITION: The temperature cannot be adjusted, or heating is insufficient.

Did you perform the Diagnostic System Check - Vehicle?

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Go to Step 2

Go to Diagnostic System Check - Vehicle.

Place the blower motor switch in each speed position.

Does the blower motor operate in any speed position?

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Go to Step 3

Go to Blower Motor Inoperative.

Check operation of air mix doors to make sure they are not jammed or broken

Is the air mix door broken or jammed?

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Go to HVAC Module Assembly Replacement.

Go to Step 3

Does the blower motor operate at the desired speeds?

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Go to Step 5

Go to Blower Motor Malfunction.

1. Start the engine.
2. Place the mode switch in the face position.
3. Place the recirculation switch in the ON position.
4. Observe the recirculation door.
5. Place the recirculation switch in the OFF position.

Does the recirculation door move from the recirculation position to the outside air position?

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Go to Step 6

Go to Air Recirculation Malfunction

Does the Too Cold in vehicle condition occur when heating or defrosting is desired?

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Go to Step 7

Go to Step 8

1. Start the engine.
2. Turn OFF the HVAC controls.

Does the A/C compressor operate?

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Go to HVAC Compressor Clutch Does Not Disengage

Go to Step 8

Inspect the cooling system for the following conditions:

Refer to Heating Performance Diagnostic.

Did you find and correct the condition?

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Go to Step 11

Go to Step 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?

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Go to Step 11

Go to Step 10

Replace the HVAC control module. Refer to Control Module References.

Did you complete the replacement?

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Go to Step 11

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Operate the system in order to verify the repair.

Did you correct the condition?

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System OK

Go to Step 2