Schematic Reference: HVAC Schematics

Connector End View Reference: HVAC Connector End Views

DEFINITION: The blower motor is inoperative in all speed positions.

Did you perform the Diagnostic System Check - Vehicle?

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Go to Step 2

Go to Diagnostic System Check - Vehicle

1. Turn ON the ignition, with the engine OFF.
2. Place the blower switch in each speed position.

Does the blower motor operate in any of the speed positions?

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Go to Blower Motor Malfunction

Go to Step 3

1. Turn OFF the ignition.
2. Disconnect the blower motor connector.
3. Turn ON the ignition, with the engine OFF.
4. Connect a test lamp between the blower motor supply voltage circuit and the blower motor control circuit.
5. Place the blower motor switch in the minimum speed position.

Does the test lamp illuminate?

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Go to Step 9

Go to Step 4

Test the battery positive voltage circuit of the blower motor control processor for an open, a high resistance or a short to ground. Refer to Circuit Testing and Wiring Repairs .

Did you find and correct the condition?

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Go to Step 15

Go to Step 5

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

Did you find and correct the condition?

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Go to Step 15

Go to Step 6

Important: Ensure that the blower motor control processor connector and the HVAC control module connectors are connected during this step in order to avoid misdiagnosis.

1. Measure the voltage from the blower motor speed control circuit at the HVAC control module to a good ground.
2. With a scan tool, command the blower motor OFF and ON.

Does the voltage measure near the specified values for each commanded state?

5 V OFF

1 V ON

Go to Step 10

Go to Step 7

1. Turn OFF the ignition.
2. Disconnect the HVAC control module.
3. Turn ON the ignition, with the engine OFF.
4. Measure the voltage from the blower motor speed control circuit of the HVAC control module to a good ground.

Does the voltage measure near the specified value?

5 V

Go to Step 11

Go to Step 8

Test the blower motor speed control circuit of the HVAC control module for an open, short to ground or short to voltage. Refer to Circuit Testing and Wiring Repairs .

Did you find and correct the condition?

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Go to Step 15

Go to Step 10

Inspect for poor connections at the harness connector of the blower motor. 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 15

Go to Step 12

Inspect for poor connections at the harness connector of the blower motor control processor. 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 15

Go to Step 13

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 15

Go to Step 14

Replace the blower motor. Refer to Blower Motor Replacement .

Did you complete the replacement?

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Go to Step 15

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Replace the blower motor control processor. Refer to Blower Motor Control Module Replacement .

Did you complete the replacement?

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Go to Step 15

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

Did you complete the replacement?

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Go to Step 15

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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