GM Service Manual Online
For 1990-2009 cars only

Circuit Description

The steering wheel controls are simple momentary contact switches that connect a series of resistors so that each switch selection corresponds to a fixed resistance value. The dash integration module (DIM) determines which switch has been pressed by the voltage drop across the corresponding resistance value.

Conditions for Running the DTC

The DIM must be powered.

Conditions for Setting the DTC

One of the temperature switches must be active (stuck) for at least 30 seconds.

Action Taken When the DTC Sets

The DIM will disable all of the steering wheel control switches while the fault is present.

Conditions for Clearing the DTC

    • The DTC will become history if the DIM no longer detects a failure.
    • The history DTC will clear after 50 fault free ignition cycles.
    • The DTC can be cleared with a scan tool.

Diagnostic Aids

Switch Position

Counts

No Input

0

TEMP DOWN

136

TEMP UP

162

If the condition is not present, refer to Testing for Intermittent Conditions and Poor Connections .

Test Description

The numbers below refer to the step numbers on the diagnostic table.

  1. This step verifies that one of the temperature switches of the steering wheel controls is active. The value given is the normal condition that exists when no switch is activated.

Step

Action

Values

Yes

No

Schematic Reference: HVAC Schematics

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. 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 data list.

Does the scan tool indicate that the counts are within the specified range?

0-7 Counts

Go Diagnostic Aids

Go to Step 3

3

Replace the steering wheel controls. Refer to Steering Wheel Control Switches Replacement in Entertainment.

Did you complete the replacement?

--

Go to Step 4

--

4

  1. Use the scan tool in order to clear the DTCs.
  2. Operate the vehicle within the Conditions for Running the DTC as specified in the supporting text.

Does the DTC reset?

--

Go to Step 2

System OK