Buick Regal: DTC B2745
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
Traction Control Switch Circuit
For symptom byte information refer to Symptom Byte List
Diagnostic Fault Information
Circuit/System Description
The body control module monitors the electronic stability control switch.
When the electronic stability
control switch is pressed once, the body control module will request the
electronic brake control module
via serial data to disable the traction control. When the electronic stability
control switch is pressed and
held for five seconds, the body control module will request the electronic brake
control module to
disable the stability control. The Electronic Brake Control Module will request
the Instrument Cluster 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 body control module detects a short to ground on the signal circuit.
Action Taken When the DTC Sets
The body control module ignores the traction control switch signal input.
Conditions for Clearing the DTC
- When the condition for setting the DTC is no longer present.
- The history DTC will clear after 40 consecutive fault-free ignition
cycles have occurred.
Reference Information
Schematic Reference
Antilock Brake System Wiring Schematics
Connector End View Reference
Component Connector End View Index
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.
2. Verify the Instrument Cluster indicators listed below turn ON and OFF when
commanding the All
Indicators ON and OFF with a scan tool.
- Traction Control Off indicator
- Stability Control Off indicator
- Traction/stability Control indicator
- If any indicator does not turn ON and OFF
Replace the P16 Instrument Cluster.
- Go to next step: If all indicators turn ON and OFF
3. Verify the scan tool Body Control Module, Traction Control Switch
parameter changes between
Active and Inactive while pressing and releasing the S75 Traction Control
Switch.
- If the parameter does not change
Refer to Circuit/System Testing.
- Go to next step: If the parameter changes
4. All OK.
Circuit/System Testing
NOTE: Circuit/System Verification must be performed before
Circuit/System
Testing.
1. Ignition OFF and all vehicle systems OFF, disconnect the harness connector
at the S75 Traction
Control Switch. It may take up to 2 min for all vehicle systems to power down.
2. Test for less than 10 Ω between the ground circuit terminal 1 and ground.
- Ignition OFF.
- Test for less than 2 Ω in the ground circuit end to end.
- If 2 Ω or greater, repair the open/high resistance in the circuit.
- If less than 2 Ω, repair the open/high resistance in the ground
connection.
- Go to next step: If less than 10 Ω
3. Ignition ON.
4. Verify the scan tool Body Control Module, Traction Control Switch parameter
is Inactive.
- Ignition OFF, disconnect the X2 harness connector at the K9 Body Control
Module.
- Test for infinite resistance between the signal circuit terminal 14 and
ground.
- If less than infinite resistance, repair the short to ground on the
circuit.
- If infinite resistance, replace the K9 Body Control Module.
- Go to next step: If Inactive
5. Install a 3 A fused jumper wire between the signal circuit terminal 3 and
ground.
6. Verify the scan tool Traction Control Switch parameter is Active.
- Ignition OFF, disconnect the X2 harness connector at the K9 Body Control
Module, ignition
ON.
- 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.
- Go to next step: If less than 1 V.
- Test for less than 2 Ω in the signal circuit end to end.
- If 2 Ω or greater, repair the open/high resistance in the circuit.
- If less than 2 Ω, replace the K9 Body Control Module.
- Go to next step: If Active
7. Test or replace the S75 Traction Control Switch.
Component Testing
1. Ignition OFF, disconnect the harness connector at the S75 Traction Control
Switch.
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 S75 Traction Control Switch.
- Go to next step: If infinite resistance
3. Test for less than 2 Ω between the signal circuit terminal 1 and the
ground terminal 3 with the
switch in the closed position.
Replace the S75 Traction Control Switch.
- Go to next step: If less than 2 Ω
4. All OK.
Repair Instructions
Perform the Diagnostic Repair Verification after completing the repair.
- Front Floor Console Trim Plate Replacement
- Control Module References for Body Control Module or Instrument Cluster
replacement,
programming and setup.
READ NEXT:
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.
Diag
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.
Diag
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.
Diag
SEE MORE:
This vehicle may have a Tire
Pressure Monitor System (TPMS).
The TPMS is designed to warn the
driver when a low tire pressure
condition exists. TPMS sensors are
mounted onto each tire and wheel
assembly, excluding the spare tire
and wheel assembly. The TPMS
sensors monitor the air pressure in
the t
Premium Recommended Fuel
Use premium 93 octane unleaded
gasoline in your vehicle. Unleaded
gasoline with an octane rating as
low as 87 may be used, but it will
reduce performance and fuel
economy.
Fuel (3.6L Engine)
Regular Fuel
Use only unleaded gasoline rated
87 octane or higher in your vehicle.