GM Service Manual Online
For 1990-2009 cars only

Circuit Description

The stability system disable indicator is controlled by the instrument cluster via class 2 serial data messages from the electronic brake control module (EBCM). When the instrument cluster sees a class 2 message from the EBCM that tells the instrument panel cluster (IPC) that the stability system is malfunctioning, the EBCM then disables vehicle stability enhancement system (VSES) and traction control system (TCS) and sends a message to the instrument cluster to turn the stability system disable indicator always on and TCS indicators ON. Each time the ignition is cycled from OFF to ON, the VSES is enabled:

The following conditions will cause the VSES/TCS indicators to illuminate:

    • The EBCM has disabled the VSES/TCS due to a DTC.
    • The instrument cluster bulb check--When the ignition switch is turned to ON, the VSES/TCS indicators will turn ON for approximately 3 seconds and then turn OFF.

Step

Action

Yes

No

Schematic Reference: Antilock Brake System Schematics

1

Did you perform the Diagnostic System Check - Vehicle?

Go to Step 2

Go to Diagnostic System Check - Vehicle in Vehicle DTC Information

2

Inspect the electronic brake control module (EBCM) ground, ensuring the ground is clear and torqued to the proper specification. Refer to Testing for Intermittent Conditions and Poor Connections and Testing for Short to Ground in Wiring Systems.

Did you find and correct the condition?

Go to Step 9

Go to Step 3

3

With a scan tool, observe the Warning Indicator parameter in the ABS/TCS/VSES data list.

Does the scan tool display Off?

Go to Step 4

Go to Step 5

4

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

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

Go to Step 5

Go to Step 6

5

Inspect for poor connections at the harness connector of the EBCM. Refer to and in Wiring Systems.

Did you find and correct the condition?

Go to Step 9

Go to Step 7

6

Inspect for poor connections at the harness connector of the 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 9

Go to Step 8

7

Replace the EBCM. Refer to Control Module References in Computer/Integrating Systems for replacement, setup, and programming.

Did you complete the repair?

Go to Step 9

-

8

Replace the IPC. Refer to Control Module References in Computer/Integrating Systems for replacement, setup, and programming.

Did you complete the replacement?

Go to Step 9

--

9

Operate the system in order to verify the repair.

Did you complete the repair?

System OK

Go to Step 2