GM Service Manual Online
For 1990-2009 cars only

Circuit Description

The mode switch is a momentary-contact, normally-open switch that can be used to disable the vehicle stability enhancement system (VSES). The mode switch is directly monitored by the electronic brake control module (EBCM). Each time the mode switch is pressed, the VSES enabled/disabled status changes. When VSES is disabled, the EBCM sends serial data messages to the instrument panel cluster (IPC) to turn ON the stability indicator.

DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC C0283 Mode Switch Circuit Malfunction

Conditions for Running the DTC

The ignition is ON.

Conditions for Setting the DTC

The EBCM detects low voltage on the traction control switch signal circuit for 8 seconds.

Action Taken When the DTC Sets

    • The EBCM disables the VSES.
    • The stability indicator turns ON.

Conditions for Clearing the DTC

The conditions for setting the DTC are no longer present and you use the scan tool Clear DTCs function.

Diagnostic Aids

Thoroughly inspect connections or circuitry that may cause an intermittent malfunction. Refer to Testing for Electrical Intermittents , Testing for Intermittent Conditions and Poor Connections , Wiring Repairs , and Connector Repairs .

Test Description

The number below refers to the step number on the diagnostic table.

  1. This step tests the traction control switch circuitry. If the fuse opens when you perform this test, the traction control switch signal circuit is shorted to ground.

Step

Action

Yes

No

Schematic Reference: Antilock Brake System Schematics

Connector End View Reference: Antilock Brake System Connector End Views

1

Did you perform the Diagnostic System Check - Vehicle?

Go to Step 2

Go to Diagnostic System Check - Vehicle

2

  1. Use a scan tool in order to clear the DTCs.
  2. Turn OFF the ignition for 5 seconds.
  3. Turn ON the ignition for up to 20 seconds.

Does the DTC set?

Go to Step 3

Go to Diagnostic Aids

3

  1. Turn OFF the ignition.
  2. Disconnect the mode switch harness connector. Refer to Electronic Traction Control Switch Replacement .
  3. Turn ON the ignition.
  4. Connect a test lamp between the ignition 3 voltage circuit and a good ground.

Does the test lamp illuminate?

Go to Step 4

Go to Step 8

4

  1. Use the scan tool in order to clear the DTCs.
  2. Turn OFF the ignition.
  3. Connect a fused jumper wire between the ignition 3 voltage circuit and the traction control switch signal circuit at the mode switch harness connector.
  4. Turn ON the ignition for up to 20 seconds.

Does the DTC set?

Go to Step 5

Go to Step 9

5

Test the traction control switch signal circuit for an open or a short to ground. Refer to Circuit Testing and Wiring Repairs .

Did you find and correct the condition?

Go to Step 11

Go to Step 6

6

Inspect for poor connections at the harness connector of the electronic brake control module (EBCM). Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs .

Did you find and correct the condition?

Go to Step 11

Go to Step 7

7

Important: Following EBCM replacement, perform the set-up procedure for the EBCM and perform the Yaw Rate Reference Table Reset Procedure. Use the scan tool to perform the Tire Size Calibration procedure.

Replace the EBCM. Refer to Control Module References .

Did you complete the replacement?

Go to Step 11

--

8

Repair the open in the ignition 3 voltage circuit. Refer to Circuit Testing and Wiring Repairs .

Did you complete the repair?

Go to Step 11

--

9

Inspect for poor connections at the harness connector of the mode switch. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs .

Did you find and correct the condition?

Go to Step 11

Go to Step 10

10

Replace the mode switch. Refer to Electronic Traction Control Switch Replacement .

Did you complete the replacement?

Go to Step 11

--

11

  1. Use the scan tool to clear the DTCs.
  2. Turn OFF the ignition for 5 seconds.
  3. Turn ON the ignition.
  4. Operate the vehicle within the Conditions for Running the DTC as specified in the supporting text.

Does the DTC reset?

Go to Step 3

System OK