Schematic Reference: HVAC Schematics

DEFINITION: Air does not flow correctly from the air distribution outlets.

1

Did you perform the HVAC Diagnostic System Check?

Go to Step 2

Go to Diagnostic System Check - HVAC Systems - Automatic

1. Turn ON the ignition, with the engine OFF.
2. Turn OFF the HVAC controls.

Is the blower motor OFF

Go to Step 3

Go to Blower Motor Always On

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 in each speed position?

Go to Step 5

Go to Blower Motor Malfunction

1. Place the blower motor switch in the maximum speed position.
2. Place the mode switch in the bi-level position.
3. Alternately place recirculation switch in the ambient air and recirculation positions.

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

Go to Step 6

Go to Air Recirculation Malfunction

1. Install a scan tool.
2. With a scan tool, perform the Recalibrate all Motors command in Instrument Panel Module Special Functions.
3. With a scan tool, observe the current DTC list in Instrument Panel Module.

Does the scan tool display any DTCs?

Go to Diagnostic Trouble Code (DTC) List

Go to Step 7

Place the mode switch in each position.

Does the display on the HVAC control module respond correctly to changes in mode selection?

Go to Step 8

Go to Step 14

Place the mode switch and defrost switch in each mode position?

Is the airflow sufficient from the correct outlets in each mode?

Go Testing for Intermittent Conditions and Poor Connections in Wiring Systems

Go to Step 9

1. With a scan tool, observe the HTR/DEF/AC Dr Commanded parameter in the Instrument Panel Module data list.
2. Place the mode switch and defrost switch in each mode position.

Does the scan tool indicate that the HTR/DEF/AC Dr Commanded parameter changes for each change in selected mode position?

Go to Step 10

Go to Step 15

Test the ignition 3 voltage circuit and the low reference circuit of the mode actuator for high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 18

Go to Step 11

Inspect the air distribution system for the following conditions:

Did you find and correct the condition?

Go to Step 18

Go to Step 12

Inspect the mode door and the mode actuator for the following conditions.

Did you find and correct the condition?

Go to Step 19

Go to Step 13

Inspect for poor connections at the harness connector of the mode actuator. 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 19

Go to Step 16

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 19

Go to Step 17

Inspect for poor connections at the harness connector of the instrument panel integration module (IPM). 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 19

Go to Step 18

Important: Perform the recalibration procedure for the mode actuator.

Replace the mode actuator. Refer to Mode Actuator Replacement .

Did you complete the replacement?

Go to Step 19

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

Did you complete the replacement?

Go to Step 19

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Important: Perform the recalibration procedure for the instrument panel integration module (IPM).

Replace the instrument panel integration module (IPM). Refer to Instrument Panel Module Replacement in Body Control System.

Did you complete the replacement?

Go to Step 19

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Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 2