GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 GMC_Truck 🢒 2009 🢒 TopKick C-Series (Conventional) C6/C7/C8 🢒 Brakes 🢒 Antilock Brake System 🢒 Low Traction Indicator Malfunction

Diagnostic Instructions
    • Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
    • Review Strategy Based Diagnosis for an overview of the diagnostic approach.
    •  Diagnostic Procedure Instructions provides an overview of each diagnostic category.

Diagnostic Fault Information

Circuit

Short to Ground

Open/High Resistance

Short to Voltage

Signal Performance

EBCM Traction Active Indicator Control Signal

1

1

2

EBCM Ignition Circuit

1

1

1. Low Traction Control Indicator Inoperative

2. Low Traction Control Indicator Always On

Circuit/System Description

The ignition voltage circuit supplies 12 volts to the traction control switch. The electronic brake control module (EBCM) illuminates the driver information center (DIC) low traction indicator by applying ground to the traction control active signal circuit.

Diagnostic Aids

Thoroughly inspect connections or circuitry that may cause an intermittent malfunction.

Reference Information

Schematic Reference

Antilock Brake System Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

ABS Description and Operation

Electrical Information Reference

    •  Circuit Testing
    •  Connector Repairs
    •  Testing for Intermittent Conditions and Poor Connections
    •  Wiring Repairs

Scan Tool Reference

Control Module References for scan tool information

Circuit/System Verification

Ignition ON, use the scan tool Low Traction Lamp Control command On and OFF. The low traction indicator should turn ON and OFF.

⇒ If the Low Traction indicator does not turn ON, go to circuit/system testing low traction indicator inoperative.
⇒ If the Low Traction indicator does not turn OFF, go to circuit/system testing low traction indicator always on.

Circuit/System Testing (Low Traction Indicator Always ON)
  1. Ignition OFF, disconnect the EBCM harness at the traction control switch terminals 38 and 25.
  2. Connect a 3A test lamp between the traction control active circuit terminal 2 and the ignition circuit terminal 3.
    3. ⇒ If the test lamp does not illuminate for 3 seconds, test the traction active circuit for a short to ground. If the circuit tests normal, test or replace the EBCM.
    ⇒ If the test lamp illuminates for 3 seconds then turns OFF, test or replace the traction control switch.

Circuit/System Testing (Low Traction Indicator Inoperative)
  1. Ignition OFF, disconnect the EBCM harness connector at the traction control switch.
  2. Ignition ON, verify that a test lamp illuminates between the EBCM ignition circuit terminal Connector C1 terminal 9 and ground.
    3. ⇒ If the test lamp does not illuminate, test the ignition circuit for a short to ground, or an open/high resistance.
    ⇒ If the circuit tests normal and the ignition circuit breaker is open, test the signal circuit terminal 38 of the EBCM for a short to ground.
  3. Verify the scan tool EBCM Traction Control Active Lamp parameter is OFF.
    4. ⇒ If not the specified value, test the signal circuit terminal for a short to voltage.
    ⇒If the circuit tests normal, replace the EBCM.
  4. Install a 3A fused jumper wire between the DIC signal circuit terminal 1 and the EBCM traction active indicator control circuit terminal 40. Verify the scan tool Traction Control Active Lamp parameter is ON.
    5. ⇒ If not the specified value, test the signal circuit terminal for an open/high resistance. If the circuit tests normal, replace the EBCM.
  5. If all circuits test normal, test or replace the traction control switch.

Component Testing
  1. Ignition OFF, disconnect the harness connector at the traction control switch.
  2. Test for infinite resistance between the signal terminal 2 and the control terminal 1 with the switch in the open position.
    3. ⇒ If not the specified value, replace the traction control switch.
  3. Test for less than 5 ohms between the signal terminal 2 and the control terminal 1 with the switch in the closed position.
    4. ⇒ If greater than the specified range, replace the switch.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

    •  Control Module References for EBCM replacement, setup, and programming
    •  Electronic Traction Control Switch Replacement

Repair Verification

Low Traction Indicator Always ON

  1. Ignition OFF for 5 seconds, Turn On the ignition. while observing the low traction indicator.
    2. ⇒ The Low traction indicator should illuminate for 3 seconds then turn OFF.
  2. Ignition ON, with scan tool command the Low Traction Lamp ON and OFF.
    3. ⇒ Low Traction indicator should turn ON and OFF, if not check circuit/system testing.