GM Service Manual Online
For 1990-2009 cars only

Object Number: 364078  Size: MF
ABS Components
Antilock Brake System Schematics
Power Distribution Schematics
Power Distribution Schematics
Instrument Cluster: Analog Schematics

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 CKT 1656 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
       - 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
       - Dirty or corroded terminals
       - A broken wire inside the insulation
    • If an intermittent malfunction exists refer to General Electrical Diagnosis in Wiring Systems for further diagnosis.
    • Zero theJ 39200 test leads before making any resistance measurements.

Low Traction Indicator On All of the Time

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. Observe the amber ABS active indicator Low Trac.
  2. Turn the ignition switch to the OFF position.

Did the amber ABS indicator LOW TRAC stay turn on?

--

Go to Step 3

Go to Step 4

3

Repair a short to voltage in CKT 1656.

Is the repair complete?

--

Go to Diagnostic System Check - ABS

--

4

  1. Inspect EBCM connectors and EBCM harness connectors C1 and C2 for poor terminal contact, damage or evidence of corrosion.
  2. Inspect the Instrument panel connectors and terminals for poor terminal contact, damage or evidence of corrosion.

Is there evidence of poor terminal contact or corrosion?

--

Go to Step 5

Go to Step 6

5

  1. Replace all terminals that exhibit signs of poor terminal contact or corrosion.
  2. Refer to General Electrical Diagnosis in Wiring Systems.
  3. Reconnect EBCM connectors and instrument panel connector.
  4. Turn the ingition switch to ON position, engine off.

Did the LOW TRAC Indicator comes on for approximate 3 seconds then turn OFF?

--

SYSTEM OK

Go to Step 6

6

Replace the EBCM.

Refer to Electronic Brake Control Module Replacement .

Is the repair complete?

--

Go to Diagnostic System Check - ABS

--