Schematic Reference: HVAC Schematics

DEFINITION: The auxiliary blower motor is inoperative in all blower motor switch positions.

Did you perform the Diagnostic System Check - Vehicle?

Go to Step 2

Go to Diagnostic System Check - Vehicle

2

Important: The auxiliary blower motor only operates at MEDIUM and HIGH speed. When the auxiliary blower switch is placed in the lowest speed setting, the air flow through the center console to the rear is provided by the primary blower motor. The air speed will vary depending on the front blower motor setting.

1. Turn ON the ignition, with the engine OFF.
2. Place the primary mode switch on the HVAC control module to the floor position.
3. Place the front blower motor switch in the minimum speed position.
4. Place the auxiliary blower motor switch in the medium speed position and the maximum speed position.

Does the auxiliary blower motor operate in either of the speed positions?

Go to Testing for Intermittent Conditions and Poor Connections

Go to Step 3

1. Cycle the auxiliary blower switch through all speed positions.
2. Observe the Rear HVAC Fan Speed parameter in the Rear HVAC/rear seat audio (RSA) data list.

Does the Rear HVAC Fan Speed parameter change with each command?

Go to Step 4

Go to Step 7

1. Turn OFF the ignition.
2. Disconnect the auxiliary blower motor.
3. Turn ON the ignition, with the engine OFF.
4. Connect a test lamp between the auxiliary blower motor high speed control circuit and a good ground.
5. Place the auxiliary blower motor switch in the maximum speed position.

Does the test lamp illuminate?

Go to Step 5

Go to Step 7

Test the ground circuit of the auxiliary blower motor for an open or high resistance. Refer to Circuit Testing and Wiring Repairs .

Did you find and correct the condition?

Go to Step 10

Go to Step 6

Inspect for poor connections at the harness connector of the auxiliary blower motor. Refer to Wiring Repairs and Connector Repairs .

Did you find and correct the condition?

Go to Step 10

Go to Step 8

Inspect for poor connections at the harness connector of the auxiliary HVAC control module. Refer to Wiring Repairs and Connector Repairs .

Did you find and correct the condition?

Go to Step 10

Go to Step 9

Replace the auxiliary blower motor. Refer to Auxiliary Blower Motor Replacement .

Did you complete the replacement?

Go to Step 10

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Replace the auxiliary HVAC control module. Refer to Control Module References for replacement, setup, and programming.

Did you complete the replacement?

Go to Step 10

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Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 3