Circuit Description
The driver may disable the traction control system (TCS) by pressing the traction control switch. The body control module (BCM) supplies a 12-volt signal on the traction control signal circuit. When the traction control switch is pressed, this voltage signal is grounded.
DTC Descriptor
This diagnostic procedure supports the following DTC:
DTC B2745 Traction Control Switch Circuit
Conditions for Running the DTC
The ignition is ON.
Conditions for Setting the DTC
The BCM detects low voltage on the traction control signal circuit for 60 seconds.
Action Taken When the DTC Sets
| • | The BCM sends a serial data message to the electronic brake control module (EBCM) informing the EBCM that the desired TCS state cannot be determined. |
| • | The EBCM defaults the TCS status to enabled. |
Conditions for Clearing the DTC
The DTC clears automatically from Current status when the fault is corrected. Use a scan tool to clear the DTC from History status.
Diagnostic Aids
An intermittent short to ground on the traction control signal circuit is the most likely cause of a history DTC when no problem is found. When the Conditions for Setting this DTC are present, the driver is not able to disable traction control.
Test Description
The number below refers to the step number on the diagnostic table.
Step | Action | Value | Yes | No |
|---|---|---|---|---|
Schematic Reference: Antilock Brake System Schematics and Body Control System Schematics in Computer/Integrating Systems Connector End View Reference: Antilock Brake System Connector End Views and Computer/Integrating Systems Connector End Views in Computer/Integrating Systems | ||||
1 | Did you perform the Diagnostic System Check - Vehicle? | -- | Go to Step 2 | Go to Diagnostic System Check - Vehicle in Vehicle DTC Information |
2 |
Does DTC B2745 set as a Current DTC? | -- | Go to Step 3 | Go to Diagnostic Aids |
Does the DTC set? | -- | Go to Step 4 | Go to Step 7 | |
4 | Use a DMM to measure the voltage between the traction control signal circuit and a good ground. Does the voltage measure greater than the specified value? | 11 V | Go to Step 6 | Go to Step 5 |
5 | Test the traction control signal circuit for a short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 8 | Go to Step 6 |
6 | Replace the body control module (BCM). Refer to Control Module References in Computer/Integrating Systems for replacement, setup, and programming. Did you complete the replacement? | -- | Go to Step 8 | -- |
7 | Replace the traction control switch. Refer to Accessory Switch Replacement in Instrument Panel, Gages, and Console. Did you complete the replacement? | -- | Go to Step 8 | -- |
8 |
Does the DTC reset? | -- | Go to Step 3 | System OK |
