GM Service Manual Online
For 1990-2009 cars only

Object Number: 307929  Size: MF
ABS Components
Antilock Brake System Schematics
Handling Electrostatic Discharge Sensitive Parts Notice
Handling Electrostatic Discharge Sensitive Parts Notice
OBDII Symbol Description Notice
OBDII Symbol Description Notice
Power Distribution Schematics
Exterior Lights Schematics
Antilock Brake System Schematics
Data Link Connector Schematics
Engine Controls Schematics

Circuit Description

This symptom table checks the state of the ETS (TRAC OFF) indicator to identify a situation in which the driver could not be warned of a system malfunction by the ETS (TRAC OFF) indicator, or the ETS (TRAC OFF) is always ON. The EBTCM sends a message to the electronic instrument panel cluster (IPC) via the Serial Data Line and the IPC will illuminate the indicator lamps.

Diagnostic Aids

Use the Lamp Test function of the Scan Tool in order to turn the indicator on while looking for an intermittent malfunction in the ABS warning indicator circuitry.

If the malfunction is not current, use wiggle test on the wiring harness to pinpoint an intermittent malfunction in the motor circuitry or connections. Thoroughly inspect any circuitry that may be causing the intermittent complaint for the following conditions:

    • Backed out terminals
    • Improper mating
    • Improperly formed or damaged terminals
    • Poor terminal-to-wiring connections
    • Physical damage to the wiring harness
    • Rubbed-through wire insulation
    • A broken wire inside the insulation

Step

Action

Value(s)

Yes

No

1

Was the Diagnostic System Check performed?

--

Go to Step 2

Go to Diagnostic System Check - ABS

2

  1. Turn the ignition switch to the OFF position.
  2. Install a scan tool.
  3. Turn the ignition switch to the ON position, engine off.
  4. Use the scan tool in order to select SPECIAL FUNCTIONS.
  5. Use the scan tool in order to select LAMP TEST.
  6. Use the scan tool in order to turn the amber ETS (TRAC OFF) warning indicator on.

Did the amber ETS (TRAC OFF) indicator turn on?

--

Go to Step 4

Go to Step 3

3

Repair the instrument panel cluster.

Refer to Instrument Cluster Replacement in Electrical Diagnosis.

Is the repair complete?

--

Go to Diagnostic System Check - ABS

--

4

Is the malfunction intermittent or not present at this time?

--

Go to Diagnostic Aids

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