Schematic Reference: HVAC Schematics

DEFINITION: The steering wheel temperature and/or blower motor switch will not adjust the HVAC temperatures or the blower speeds. No DTCs have been set.

Did you perform the HVAC Diagnostic System Check?

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Go to Step 2

Go to Diagnostic System Check - HVAC Systems - Automatic

1. Install a scan tool.
2. Turn ON the ignition, with the engine OFF.
3. With a scan tool, observe the Steering Wheel Controls parameter in the dash integration module (DIM) data list.
4. Press each radio and HVAC switch in both directions.

Do the counts change for any switch pressed?

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Go to Step 3

Go to Step 5

1. With a scan tool observe the Steering Wheel Controls parameter in the DIM data list.
2. Press each radio and HVAC switch in both directions.

Do the counts change for all switches pressed?

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Go to Step 4

Go to Step 9

1. Turn ON the radio.
2. Increase and decrease the volume with the right steering wheel controls switch.

Do the radio steering wheel controls function?

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Go to Too Hot in Vehicle or Too Cold in Vehicle

Go to Step 10

Caution: When you are performing service on or near the SIR components or the SIR wiring, you must disable the SIR system. Refer to Disabling the SIR System. Failure to follow the correct procedure could cause air bag deployment, personal injury, or unnecessary SIR system repairs.

1. Disable the SIR system. Refer to Disabling the SIR System in SIR.
2. Turn OFF the ignition.
3. Remove and disconnect the left steering wheel controls. Refer to Steering Wheel HVAC Control Assembly Replacement .
4. Turn ON the ignition, with the engine OFF.
5. Connect a 3-amp fused jumper wire between the remote radio control head supply voltage circuit and the steering wheel controls circuit of the left steering wheel controls.

Do the counts change?

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Go to Step 9

Go to Step 6

Measure the voltage from the remote radio control head supply voltage circuit at the left steering wheel controls to a good ground.

Does the voltage measure near the specified value?

12 V

Go to Step 7

Go to Step 8

Test the steering wheel controls circuit of the left steering wheel controls for an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

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Go to Step 13

Go to Step 10

Test the remote radio control head supply voltage circuit of the left steering wheel controls for an open or a short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

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Go to Step 13

Go to Step 10

Inspect for poor connections at the harness connector of the left steering wheel controls. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

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Go to Step 13

Go to Step 11

Inspect for poor connections at the harness connector of the DIM. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

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Go to Step 13

Go to Step 12

Replace the left steering wheel controls. Refer to Steering Wheel HVAC Control Assembly Replacement .

Did you complete the replacement?

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Go to Step 13

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Replace the DIM. Refer to Body Control Module (BCM) Programming/RPO Configuration and Dash Integration Module Replacement in Body Control System.

Did you complete the replacement?

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Go to Step 13

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Enable the SIR system. Refer to Enabling the SIR System in SIR.

Is the SIR system enabled?

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Go to Step 14

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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