GM Service Manual Online
For 1990-2009 cars only

Circuit Description

The LOW TRAC Indicator is controlled by the EBCM. The LOW TRAC Indicator is activated during a traction control event only. When the EBCM detects a low traction condition it supplies a ground for LOW TRAC indicator control circuit turning on the LOW TRAC Indicator.

Diagnostic Aids

    • It is very important that a thorough inspection of the wiring and connectors be performed. Failure to carefully and fully inspect wiring and connectors may result in misdiagnosis, causing part replacement with reappearance of the malfunction.
    • Thoroughly inspect any circuitry that may be causing the complaint for the following conditions:
       - Backed out terminals
       - Improper mating
       - Broken locks
       - Improperly formed or damaged terminals
       - Poor terminal-to-wiring connections
       - Physical damage to the wiring harness
    • The following conditions may cause an intermittent malfunction:
       - A poor connection
       - Rubbed-through wire insulation
       - A broken wire inside the insulation
    • If an intermittent malfunction exists refer to General Electrical Diagnosis in Wiring systems for further diagnosis.

Test Description

The number(s) below refer to the step number(s) on the diagnostic table.

  1. This step checks for an internal EBCM short.

  2. This step checks for a short to ground in the LOW TRAC indicator control circuit.

Step

Action

Value(s)

Yes

No

Schematic Reference: Antilock Brake System Schematics

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. Disconnect the EBCM connector C1.
  3. Turn the ignition switch to the RUN position.

Is the LOW TRAC Indicator off?

--

Go to Step 3

Go to Step 4

3

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

Is the replacement complete?

--

Go to Step 7

--

4

  1. Install the Universal Pinout Box J 39700 using the J 39700-530 cable adapter to connector C1 only.
  2. Disconnect the Driver Information Display (Base) or Trip Calculator (Up Level) connector.
  3. Using the DMM, measure the resistance between terminals 25 and 15 of the Universal Pinout Box.

Is the resistance within the range specified in the value(s) column?

OL (Infinite)

Go to Step 6

Go to Step 5

5

Repair Traction Active indicator control circuit for a short to ground. Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

--

Go to Step 7

--

6

Suspect the Driver Information Display (Base) or Trip Calculator (Up Level). Refer to Driver Information Center Module Replacement in Instrument Panel, Gauges and Console.

Is the repair complete?

--

Go to Step 7

--

7

Operate the system in order to verify the repair.

Did you correct the condition?

--

System OK

Go to Step 2