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

  1. This step checks for an internal EBCM malfunction.

  2. This step checks for an open in LOW TRAC indicator control circuit.

Step

Action

Value(s)

Yes

No

Schematic Reference: Antilock Brake System Schematics

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

1

Did you perform the Diagnostic System Check?

--

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. Install the J 39700 Universal Pinout Box using J 39700-530 Cable Adapter to connector C1 only.
  4. Connect a fused jumper wire between terminals 25 and 15 of J 39700 .
  5. Turn the ignition switch to the RUN position.

Does the LOW TRAC Indicator come on?

--

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. Turn the ignition switch to the OFF position.
  2. Disconnect the drive information display (base) or trip calculator (up level) connector. Refer to Instrument Panel, Gages, and Console Connector End Views in Instrument Panel, Gages and Console for connector pinout.
  3. Using J 39200 DMM, measure the resistance between terminals 25 of and the driver information display (Base) or trip calculator (up level) harness connector terminal H (driver information display) or A3 (trip calculator).

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

0-5ohms

Go to Step 6

Go to Step 5

5

Repair Traction Active indicator control circuit for an open or high resistance. 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, Gages 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