For 1990-2009 cars

### Circuit Description

The body control module (BCM) illuminates the LED on the traction control switch (TCS), by supplying adequate current to the high side of the LED. This LED is referred to as the traction off indicator.

### Diagnostic Aids

Thoroughly inspect connections or circuitry that may cause an intermittent malfunction. Refer to the following:

• | Testing for Electrical Intermittents

• | Testing for Intermittent Conditions and Poor Connections

• | Wiring Repairs

• | Connector Repairs

### Test Description

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

1. The traction control switch may be damaged if the traction control switch signal circuit is shorted to voltage.

Step | Action | Yes | No
--- | --- | --- | ---
1 | Did you perform the Diagnostic System Check - Vehicle? | Go to Step 2 | Go to Diagnostic System Check - Vehicle
2 |

1. Turn ON the ignition.
2. Press and release the traction control switch.

Does the traction off indicator illuminate?

Go to Diagnostic Aids

Go to Step 3

3 | Important: Do not press the traction control switch continuously for more than 60 seconds to avoid setting DTC B2745.

1. Select body control module (BCM)/Data Display/Inputs on the scan tool.
2. Observe the traction control system (TCS) Switch State parameter while pressing the traction control switch.

Does the scan tool display the switch state as Pressed?

Go to Step 8

Go to Step 4

4 | Important: DTC B0828 sets when this test is performed.

1. Turn OFF the ignition.
2. Disconnect the traction control switch harness connector.
3. Turn ON the ignition.
4. Use a test lamp connected to a good ground to carefully probe the traction control switch signal circuit terminal within the traction control switch harness connector.

Does the test lamp illuminate?

Go to Step 6

Go to Step 5

5 | Observe the TCS Switch State parameter on the scan tool while the test lamp is connected. Does the scan tool display the switch state as Pressed? | Go to Step 8 | Go to Step 7
6 | Test the traction control switch signal circuit for a short to voltage. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition? | Go to Step 12 | Go to Step 11
7 | Test the traction control switch signal circuit for an open. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition? | Go to Step 12 | Go to Step 9
8 | Test for poor connections at the harness connector of the traction control switch. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs . Did you find and correct the condition? | Go to Step 12 | Go to Step 10
9 | Test for poor connections at the harness connector of the BCM. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs . Did you find and correct the condition? | Go to Step 12 | Go to Step 11
10 | Replace the accessory switch. Refer to Accessory Switch Replacement . Did you complete the replacement? | Go to Step 12 | --
11 | Replace the BCM. Refer to Control Module References for replacement, setup, and programming. Did you complete the replacement? | Go to Step 12 | --
12 |

1. Turn ON the ignition.
2. Press and release the traction control switch.

Does the traction off indicator illuminate?

System OK

Go to Step 3