GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Buick 🢒 2001 🢒 Century 🢒 Brakes 🢒 Antilock Brake System 🢒 Traction Off Indicator Inoperative

Circuit Description

The Traction Off indicator is controlled by the instrument cluster via serial data messages from the EBCM. When the body control module sees the traction control switch input grounded through the momentary traction control switch, it sends a serial data message to the EBCM that tells the EBCM that the traction control switch has been pressed. The EBCM then disables traction control and sends a serial data message to the instrument cluster to turn the Traction Off indicator ON. Each time the ignition is cycled from OFF to ON, the traction control system is enabled.

The following conditions will cause the Traction Off indicator to illuminate:

    • The EBCM has disabled the TCS due to a DTC.
    • The driver manually disabling the TCS via the traction control switch.
    • The instrument cluster bulb check. When the ignition switch is turned to ON, the Traction Off indicator will turn on for approximately 3 seconds and then turn OFF.

Test Description

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

  1. Use the scan tool to check the normal state of the Traction Off indicator control.

    2.

  2. Ensures that the instrument cluster can operate the Traction Off indicator.

Step

Action

Yes

No

Schematic Reference: Antilock Brake System Schematics

Connector End View Reference: Antilock Brake System Connector End Views , Body Control System Connector End Views in Body Control System, or Instrument Panel, Gages, and Console Connector End Views in Instrument Panel, Gages, and Console

1

Did you perform the ABS Diagnostic System Check?

Go to Step 2

Go to Diagnostic System Check - ABS

2

  1. Install a scan tool.
  2. Turn ON the ignition, with the engine OFF.
  3. With a scan tool, observe the TCS Warning Lamp parameter in the TCS data list (w/NW9) or ETS Warning Lamp parameter in the ETS data list (w/NW7).

Does the scan tool display Off?

Go to Step 3

Go to Step 10

3

  1. Turn OFF the ignition.
  2. Turn ON the ignition, with the engine OFF.
  3. Observe the Traction Off indicator on the instrument cluster (IPC) during the bulb check.

Does the Traction Off indicator illuminate during the bulb check and then turn OFF?

Go to Step 4

Go to Step 11

4
  1. Turn OFF the ignition.
  2. Install a scan tool.
  3. Turn ON the ignition, with the engine OFF.
  4. With a scan tool, observe the TCS Switch parameter in the Body Control Module data list.
  5. Activate the traction control switch.

Does the TCS Switch parameter change state?

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

Go to Step 5

5
  1. Turn OFF the ignition.
  2. Disconnect the traction control switch connector.
  3. Connect a 3 amp fused jumper from the signal circuit of the traction control switch to the ground circuit of the traction control switch.
  4. Turn ON the ignition, with the engine OFF.
  5. With a scan tool, observe the TCS Switch parameter.

Does the scan tool display On?

Go to Step 9

Go to Step 6

6

Test the signal circuit of the traction control switch for an open or high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 16

Go to Step 7

7

Test the ground circuit of the traction control switch for an open or high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 16

Go to Step 8

8

Inspect for poor connections at the harness connector of the body control module (BCM). 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 12

9

Inspect for poor connections at the harness connector of the traction control switch. 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

10

Inspect for poor connections at the harness connector of the EBCM. 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

11

Inspect for poor connections at the harness connector of the instrument cluster (IPC). 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

12

Important: Perform the setup procedure for the body control module. Refer to Body Control Module (BCM) Programming/RPO Configuration in Body Control System.

Replace the body control module (BCM). Refer to Body Control Module Replacement in Body Control System.

Did you complete the replacement?

Go to Step 16

--

13

Replace the traction control switch. Refer to Electronic Traction Control Switch Replacement .

Did you complete the replacement?

Go to Step 16

--

14

Replace the EBCM. Refer to Electronic Brake Control Module Replacement .

Did you complete the repair?

Go to Step 16

--

15

Replace the instrument cluster (IPC). Refer to Instrument Cluster Replacement in Instrument Panel, Gages and Console.

Did you complete the repair?

Go to Step 16

--

16

Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 2