GM Service Manual Online
For 1990-2009 cars only

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.

DTC Descriptor

DTC B2745 00: Traction Control Switch Circuit

Diagnostic Fault Information

Circuit

Short to Ground

Open/High Resistance

Short to Voltage

Signal Performance

Signal

--

1

B2745

--

Ground

--

1

--

--

Circuit/System Description

The traction control system (TCS) switch is a normally open switch that closes when the switch is activated. When activated, the switch grounds the TCS signal circuit. The body control module (BCM) converts the signal into serial data, which is used by the electronic brake control module (EBCM) to enable/disable the TCS.

Conditions for Running the DTC

    • Ignition ON.
    • Ignition voltage is greater than 10 volts.

Conditions for Setting the DTC

The BCM detects the TCS switch is activated for 60 seconds or more.

Action Taken When the DTC Sets

    • The EBCM disables the ABS/traction control system (TCS)/vehicle stability enhancement system (VSES) for the duration of the ignition cycle.
    • A DIC message and/or a warning indicator may be displayed.

Conditions for Clearing the DTC

    • The conditions for setting the DTC are no longer present.
    • The EBCM clears the history DTC when a current DTC is not detected in 100 consecutive drive cycles.

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

  1. Ignition ON, with a scan tool command the IPC display test ON and OFF. The StabiliTrak indicator should turn ON and OFF.
  2. If the indicator does not turn ON and OFF, replace the IPC.
  3. Observe the scan tool BCM Traction Control Switch parameter while pressing and releasing the traction control switch. The reading should change between Active and Inactive.

Circuit/System Testing

  1. Ignition OFF, disconnect the harness connector at the traction control switch.
  2. Test for less than 1 ohm between the ground circuit terminal 2 and ground.
  3. If greater than the specified range, test the ground circuit for an open/high resistance.
  4. Ignition ON, verify the scan tool Traction Control Switch parameter is Inactive.
  5. If not the specified value, test the signal circuit terminal 8 for a short to ground.
  6. Install a 3A fused jumper wire between the signal circuit terminal 8 and the ground circuit terminal 2. Verify the scan tool Traction Control Switch parameter is Active.
  7. If not the specified value, test the signal circuit for a short to voltage or an open/high resistance.
  8. If all circuits test normal, test or replace the traction control switch. If the DTC resets, replace the BCM.

Component Testing

  1. Ignition OFF, disconnect the harness connector at the traction control switch.
  2. Test for infinite resistance between the signal terminal 8 and the ground terminal 2 with the switch in the open position.
  3. If not the specified value, replace the traction control switch.
  4. Test for less than 3 ohms between the signal terminal 8 and the ground terminal 2 with the switch in the closed position.
  5. If greater than the specified range, replace the traction control switch.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Control Module References for BCM replacement, setup, and programming