GM Service Manual Online
For 1990-2009 cars only

Step

Action

Value(s)

Yes

No

Schematic Reference: HVAC Schematics

Connector End View Reference: HVAC Connector End Views

DEFINITION: The left steering wheel control does not operate properly.

1

Did you perform the HVAC Diagnostic System Check?

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Go to Step 2

Go to Diagnostic System Check - HVAC Systems - Automatic

2

  1. With a scan tool, observe the SWC Switch Voltage parameter in the Body Control Module data list.
  2. Activate each of the left steering wheel control switches.

Does the scan tool indicate that the value of the SWC Switch Voltage parameter changes when each switch is activated?

--

Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems

Go to Step 3

3

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 the ignition OFF.
  3. Disconnect the left steering wheel controls.
  4. Turn ON the ignition, with the engine OFF.
  5. With a scan tool observe the SWC Switch Voltage parameter.
  6. Connect a 3 amp fused jumper wire between the supply voltage circuit of the left steering wheel controls and the signal circuit of the remote blower motor switch.

Does the scan tool indicate that the value of the SWC Switch Voltage parameter changes?

--

Go to Step 4

Go to Step 5

4

  1. Disconnect the fused jumper wire.
  2. With a scan tool observe the SWC Switch Voltage parameter.
  3. Connect a 3 amp fused jumper wire between the supply voltage circuit of the left steering wheel controls and the signal circuit of the remote air temperature switch.

Does the scan tool indicate that the value of the SWC Switch Voltage parameter changes?

--

Go to Step 10

Go to Step 9

5

Measure the voltage from the supply voltage circuit of the left steering wheel controls to a good ground.

Does the voltage measure greater than the specified value?

10 V

Go to Step 9

Go to Step 6

6

Measure the voltage from the supply voltage circuit of the right steering wheel controls to a good ground.

Does the voltage measure greater than the specified value?

10 V

Go to Step 7

Go to Step 8

7

Test the supply voltage circuit of the left steering wheel controls for a short to ground, a high resistance or an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 16

Go to Step 11

8

Test the supply voltage circuit of the right steering wheel controls for a short to ground, a high resistance or an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 16

Go to Step 12

9

Test the signal circuit of the left steering wheel controls for a short to ground, a high resistance or an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 16

Go to Step 12

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?

--

Go to Step 16

Go to Step 13

11

Inspect for poor connections at the harness connector of the right 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?

--

Go to Step 16

Go to Step 14

12

Inspect for poor connections at the harness connector of the body 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 16

Go to Step 15

13

Replace the left steering wheel control switch. Refer to Steering Wheel Control Switch Assembly Replacement in Steering Wheel and Column.

Did you complete the replacement?

--

Go to Step 16

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14

Replace the right steering wheel control switch. Refer to Steering Wheel Control Switch Assembly Replacement in Steering Wheel and Column.

Did you complete the replacement?

--

Go to Step 16

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15

Important: Perform the set up procedure for the body control module.

Replace the body control module. Refer to Body Control Module Replacement .

Did you complete the replacement?

--

Go to Step 16

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16

Operate the system in order to verify the repair.

Did you correct the condition?

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System OK

Go to Step 3