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 HVAC Diagnostic System Check?

Go to Step 2

Go to Diagnostic System Check - HVAC Systems - Manual

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 .

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

Go to Diagnostic Trouble Code (DTC) List

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

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

Perform the Heating Performance Diagnostic. Refer to Heating Performance Diagnostic in Heating, Ventilation and Air Conditioning.

Did you find and correct the condition?

Go to Step 11

Go to Step 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

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 11

Go to Step 10

Important: Perform the recalibration procedure for the HVAC control module. Refer to Actuator Recalibration .

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

Did you complete the replacement?

Go to Step 11

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Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 2