GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Oldsmobile 🢒 2000 🢒 Intrigue 🢒 Brakes 🢒 Antilock Brake System 🢒 DTC C0252 Active Brake Control Sensors Uncorrelated

Circuit Description

The vehicle stability enhancement system (VSES) is activated by the EBCM calculating the desired yaw rate and comparing it to the actual yaw rate input. The desired yaw rate is calculated from measured steering wheel position, vehicle speed, and lateral acceleration. The difference between the desired yaw rate and actual yaw rate is the yaw rate error, which is a measurement of oversteer or understeer. If the yaw rate error becomes too large, the EBCM will attempt to correct the vehicle's yaw motion by applying differential braking to the left or right wheels..

Conditions for Running the DTC
    • The steer angle has been centered.
    • The VSES is active.
    • The direction (understeer or oversteer) of the yaw rate error has not changed.
    • The lateral acceleration is less than 0.5 g.

Conditions for Setting the DTC

One of the following conditions occur:

    • The VSES is engaged for 10 seconds with the yaw rate error always in either understeer or oversteer. Under this condition, this DTC will set by itself.
    • The yaw rate error is greater than 10 degrees/second for 5 seconds.

Action Taken When the DTC Sets
    • A malfunction DTC is set.
    • VSES is disabled.
    • ABS, TCS, SERVICE VEHICLE SOON and PCS indicator lamps are on.

Conditions for Clearing the DTC
    • The condition for the DTC is no longer present (the DTC is not current) and you used the scan tool Clear DTC function.
    • The EBCM automatically clears the history DTC when a current DTC is not detected in 124 consecutive drive cycles.

Diagnostic Aids
    • During diagnosis, park the vehicle on a level surface.
    • Check the vehicle for proper alignment. The car should not pull in either direction while driving straight on a level surface.
    • Find out from the customer the conditions under which the DTC was set. This information will help to duplicate the failure.
    • The Snapshot function on the scan tool can help find an intermittent DTC.

Test Description

The numbers below refer to the step numbers on the diagnostic table.

  1. This checks to see if DTC C0252 is set.

    2.

  2. This step checks to see if the DTC C0252 resets.

    3.

  3. This step checks to see if VSES data list parameters are correct.

    4.

  4. This step checks the components harness connectors for poor connections.

Step

Action

Value(s)

Yes

No

1

Did you perform the ABS Diagnostic System Check?

--

Go to Step 2

Go to Diagnostic System Check - ABS

2

  1. Turn OFF the ignition.
  2. Install a scan tool.
  3. Turn ON the ignition, with the engine OFF.
  4. Select the ABS DTC display function.

Does the scan tool display any DTC other than DTC C0252?

--

Go to Diagnostic Trouble Code (DTC) List

Go to Step 3

3

  1. Use the scan tool in order to clear the DTC.
  2. Perform the Diagnostic Test Drive .
  3. Use the scan tool to select the ABS DTC display function.

Does the DTC reset?

--

Go to Step 4

Go to Diagnostic Aids

4

  1. Use the scan tool to select the VSES data list.
  2. Compare data to the typical values located in the EBCM scan tool data list under VSES Data List. Refer to Scan Tool Data List .

Are all parameters correct?

--

Go to Step 5

Go to Intermittents and Poor Connections

5

Check the wiring harness connectors for the following:

    • EBCM
    • Brake pressure sensor
    • Steering angle sensor
    • Yaw/lateral accelerometer sensor
    • LF wheel speed sensor
    • RF wheel speed sensor
    • RF wheel speed sensor
    • RR wheel speed sensor

Did you find and correct the condition?

--

Go to Step 6

Go to Intermittents and Poor Connections

6
  1. Reconnect previously disconnected components and connectors.
  2. Use the scan tool in order to clear the DTCs.

Did you complete the action?

--

Go to Step 2

System OK