Operation CHARM: Car repair manuals for everyone.

B2745




DTC B2745

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle Diagnostic System Check - Vehicle prior to using this diagnostic procedure.

* Review Strategy Based Diagnosis Strategy Based Diagnosis for an overview of the diagnostic approach.

* Diagnostic Procedure Instructions Diagnostic Procedure Instructions provides an overview of each diagnostic category.

DTC Descriptor

DTC B2745 00

-
Traction Control Switch Circuit Malfunction

DTC B2745 02

-
Traction Control Switch Circuit Short to Ground

Diagnostic Fault Information






Circuit/System Description

When the traction control switch is pressed, the signal circuit from the body control module (BCM) circuit is pulled low indicating the performance mode request. In response to this signal, the BCM sends a serial data message to the electronic brake control module (EBCM) to disable the traction/stability control system and illuminate the traction/stability control OFF indicator.

Conditions for Running the DTC

* Ignition ON.

* Ignition voltage is greater than 10 V.

Conditions for Setting the DTC

The BCM detects the traction control switch active for greater than 60 seconds.

Action Taken when the DTC Sets

* The ABS indicator turns ON.

* The traction control/stability control-active indicator off turns ON.

* The EBCM disables the antilock brake system, the traction control system and the electronic stability program for the duration of the ignition cycle.

Conditions for Clearing the DTC

* The conditions for setting the DTC are no longer present.

* The history DTC will clear after 40 consecutive fault-free ignition cycles have occurred.

Note:
During normal diagnostic and/or repair verification technicians may find that the ABS, Traction Control and/or Stabilitrak indicators may be ON with NO DTCs displayed by the EBCM. Do not replace the EBCM for this condition.

If the ABS, Traction Control and/or Stabilitrak telltales are ON with no DTCs set, perform the following steps:

1. Remove the key from the ignition, open and close the driver's door to turn off retained accessory power (RAP), and wait 60 seconds.

2. Ignition ON, if the ABS, Traction Control and/or Stabilitrak telltales are still illuminated, operate the vehicle at speeds greater than 15 km/h (10 mph) to complete the self test. The EBCM should request all telltale indicators to turn OFF.

3. If the telltales remain ON with no DTCs set after the drive cycle, disconnect the battery for at least 60 seconds then reconnect the battery.

4. Operate the vehicle at speeds greater than 40 km/h (25 mph), the EBCM should request all telltale indicators to turn OFF.

Reference Information

Schematic Reference

Antilock Brake System Schematics [1][2]Antilock Brakes / Traction Control Systems

Connector End View Reference

Component Connector End Views Fuel Pump and Level Sensor Assembly

Description and Operation

ABS Description and Operation Description and Operation

Electrical Information Reference

* Circuit Testing Circuit Testing

* Connector Repairs Connector Repairs

* Testing for Intermittent Conditions and Poor Connections Testing for Intermittent Conditions and Poor Connections

* Wiring Repairs Wiring Repairs

Scan Tool Reference

Control Module References Control Module References for scan tool information

Circuit/System Verification

1. Ignition ON, command the IPC Display Test ON and OFF with a scan tool. The Stabilitrak indicator should turn ON and OFF when changing between the commanded states.

If the indicator does not turn ON and OFF, replace the instrument cluster.

2. 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 center console multifunction switch.

2. Test for less than 5 ohms between the ground circuit terminal 2 ground.

If greater than the specified range, test the ground circuit for an open/high resistance.

3. Ignition ON, verify the scan tool Traction Control Switch parameter is Inactive.

If not the specified value, test the signal circuit terminal 3 for a short to ground. If the circuit tests normal, replace the BCM.

4. Install a 3 A fused jumper wire between the signal circuit terminal 3 and the ground circuit terminal 2. Verify the scan tool Traction Control Switch parameter is Active.

If not the specified value, test the signal circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the BCM.

5. If all circuits test normal, test or replace the center console multifunction switch.

Component Testing

1. Ignition OFF, disconnect the harness connector at the center console multifunction switch.

2. Test for infinite resistance between the signal terminal 3 and the a ground circuit terminal 2 with the switch in the open position.

If not the specified value, replace the center console multifunction switch.

3. Test for less than 3 ohms between the signal terminal 3 and the ground terminal 2 with the switch in the closed position.

If greater than the specified range, replace the center console multifunction switch.

Repair Instructions

Perform the Diagnostic Repair Verification Verification Tests after completing the diagnostic procedure.

* Console Trim Plate Replacement (9C3) Console Trim Plate Replacement (9C3)

* Control Module References Control Module References for BCM or instrument cluster replacement, programming and setup