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 02
-
Traction Control Switch Circuit Short to Ground
Diagnostic Fault Information
Circuit/System Description
The body control module (BCM) monitors the traction control switch. When the traction control switch is pressed once, the BCM will request the electronic brake control module (EBCM) via serial data to disable the traction control. The EBCM will request the instrument cluster via serial data to turn the traction control off and stability control off indicator ON to notify the driver of the deactivation.
Conditions for Running the DTC
Ignition ON.
Conditions for Setting the DTC
The BCM detects a short to ground on the signal circuit.
Action Taken When the DTC Sets
The BCM ignores the traction control switch signal input.
Conditions for Clearing the DTC
* The condition for the DTC is no longer present.
* The EBCM clears the history DTC when a current DTC is not detected in 40 consecutive drive cycles.
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 1-2 Shift Solenoid (SS) Valve (M30)
Description and Operation
ABS Description and Operation (Without JL4) Description and OperationABS Description and Operation (With JL4) 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.
2. Verify the scan tool Body Control Module, Traction Control Switch parameter changes between Active and Inactive when pressing and releasing the traction control switch.
• If the parameter does not change
Refer to Circuit/System Testing.
• If the parameter changes
3. All OK.
Circuit/System Testing
1. Ignition OFF and all vehicle systems OFF, disconnect the harness connector at the multifunction switch assembly-I/P. It may take up to 2 minutes for all vehicle systems to power down.
2. Test for less than 5 ohms between the ground circuit terminal 3 and ground.
• If 5 ohms or greater
1. Ignition OFF.
2. Test for less than 2 ohms in the ground circuit end to end.
• If 2 ohms or greater, repair the open/high resistance in the circuit.
• If less than 2 ohms, repair the open/high resistance in the ground connection.
• If less than 5 ohms
3. Ignition ON.
4. Verify the scan tool Traction Control Switch parameter is Inactive.
• If not Inactive
1. Ignition OFF, disconnect the X2 harness connector at the BCM.
2. Test for infinite resistance between the signal circuit and ground.
• If less than infinite resistance, repair the short to ground on the circuit.
• If infinite resistance, replace the BCM.
• If Inactive
5. Install a 3 A fused jumper wire between the signal circuit terminal 1 and the ground circuit terminal 3.
6. Verify the scan tool Traction Control Switch parameter is Active.
• If not Active
1. Ignition OFF, disconnect the X2 harness connector at the BCM, ignition ON.
2. Test for less than 1 V between the signal circuit and ground.
• If 1 V or greater, repair the short to voltage on the circuit.
• If less than 1 V
3. Test for less than 2 ohms in the signal end to end.
• If 2 ohms or greater, repair the open/high resistance in the circuit.
• If less than 2 ohms, replace the BCM.
• If Active
7. Test or replace the multifunction switch assembly-I/P.
Component Testing
1. Ignition OFF, disconnect the harness connector at the multifunction switch assembly-I/P.
2. Test for infinite resistance between the signal terminal 1 and the ground terminal 3 with the switch in the open position.
• If less than infinite resistance
Replace the multifunction switch assembly-I/P
• If infinite resistance
3. Test for less than 5 ohms between the signal terminal 1 and the ground terminal 3 with the switch in the closed position.
• If 5 ohms or greater
Replace the multifunction switch assembly-I/P
• If less than 5 ohms
4. All OK.
Repair Instructions
Perform the Diagnostic Repair Verification Verification Tests after completing the repair.
* Accessory Switch Replacement (without RPO SLT) Accessory Switch Replacement (without RPO SLT)Accessory Switch Replacement (with RPO SLT) Accessory Switch Replacement (with RPO SLT)
* Control Module References Control Module References for BCM or IPC replacement, programming and setup