Schematic Reference: HVAC Schematics

Connector End View Reference: HVAC Connector End Views

DEFINITION: The temperature cannot be adjusted, or the cooling is insufficient during A/C operation.

1

Did you perform the Diagnostic System Check - Vehicle?

Go to Step 2

Go to Diagnostic System Check - Vehicle in Vehicle DTC Information

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 in Vehicle DTC Information.

Does the scan tool display any DTC B0414, B0424 or B3770?

Go to Diagnostic Trouble Code (DTC) List - Vehicle in Vehicle DTC Information

Go to Step 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

Does the blower motor operate at the desired speed?

Go to Step 5

Go to Blower Motor Malfunction

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

Does the customer concern occur when the A/C is OFF?

Go to Step 9

Go to Step 7

Important: Ambient air temperature must be above 3°C (36°F).

1. Start the engine.
2. Place the blower motor switch in the maximum speed position.
3. Place the A/C request switch in the ON position.
4. Place temperature switch in the coldest position.

Does the A/C compressor operate?

Go to Step 8

Go to HVAC Compressor Clutch Does Not Engage

Perform the refrigerant system performance test. Refer to Air Conditioning (A/C) System Performance Test in Heating, Ventilation and Air Conditioning.

Did you find and correct the condition?

Go to Step 12

Go to Step  9

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 10

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 in Wiring Systems.

Did you find and correct the condition?

Go to Step 12

Go to Step 11

Replace the HVAC control module. Refer to Control Module References in Computer/Integrating Systems for replacement, setup, and programming.

Did you complete the replacement?

Go to Step 12

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Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 2