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 Instrument Cluster (IPC) determines which switch has been pressed by the voltage drop across the corresponding resistance value.

Conditions for Running the DTC

This test is run every 300 milliseconds.

Conditions for Setting the DTC

The switch must be stuck (pressed) for at least 5 seconds.

Action Taken When the DTC Sets

The Instrument Cluster (IPC) will ignore the switch command.

Conditions for Clearing the MIL/DTC

The stuck switch condition must be corrected.

Diagnostic Aids

    • The following may cause an intermittent:
       - A bent terminal
       - A backed out terminal
       - A damaged terminal
       - Poor terminal tension
       - A chafed wire
       - A broken wire inside the insulation
    • When diagnosing for an intermittent short or an open, massage the wire harness while watching the test equipment for changes.

Test Description

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

  1. This step verifies that the steering wheel convenience switch is stuck. The convenience switches operate in the 123-247 count range. The value given is the normal condition that exists when no switch is activated.

Step

Action

Value(s)

Yes

No

Schematic Reference: Steering Wheel Controls Schematics

1

Did you perform the Radio/Audio System Diagnostic System Check?

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Go to Step 2

Go to Diagnostic System Check - Radio/Audio System

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.

Does the Steering Wheel Controls parameter indicate the specified range?

0-7 Counts

Go to Diagnostic Aids

Go to Step 3

3

Replace the steering wheel convenience switches. Refer to Steering Wheel Control Switches Replacement .

Did you complete the replacement?

--

Go to Step 4

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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