Hello. Thanks for the donation. Much appreciated
Start by having the car plugged into a diagnostic computer and repost with full fault codes for more assistance.
Vehicle Stability Enhancement System (VSES)
The vehicle stability enhancement system (VSES) adds an additional level of vehicle control to the EBCM.
Yaw rate is the rate of rotation about the vehicle's vertical axis. The VSES is activated when the EBCM determines that the desired yaw rate does not match the actual yaw rate as measured by the yaw rate sensor.
The desired yaw rate is calculated from the following parameters:
The position of the steering wheel
The speed of the vehicle
The lateral, or sideways acceleration of the vehicle
The difference between the desired yaw rate and the actual yaw rate is the yaw rate error, which is a measurement of over steer or under steer. If the yaw rate error becomes too large, the EBCM attempts to correct the vehicle's yaw motion by applying differential braking to the appropriate wheel. The amount of differential braking applied to the left or right front wheel is based on both the yaw rate error and side slip rate error.
The VSES activations generally occur during aggressive driving, in turns or on bumpy roads without much use of the accelerator pedal. When braking during VSES activation, the pedal pulsations feel different than the ABS pedal pulsations. The brake pedal pulsates at a higher frequency during VSES activation.
ECE 13 Response
The electronic brake control module (EBCM) illuminates the ABS indicator when a malfunction which disables ABS is detected. Usually, the ABS indicator is turned OFF during the following ignition cycle unless the fault is detected during that ignition cycle. However, the setting of a wheel speed sensor related DTC causes the ABS indicator to remain illuminated during the following ignition cycle until the vehicle is operated at a speed greater than 13 km/h (8 mph). This allows the EBCM to verify that no malfunction exists, before turning OFF the ABS indicator. This reaction occurs even if the ABS indicator turns OFF when the scan tool is used to clear the DTCs. When repairing these vehicles, it is important to ensure that the ECE 13 response has occurred and that the ABS indicator does not illuminate after returning the vehicle to the customer. It is also important to verify that ECE 13 is not the cause of an ABS indicator which is illuminated when no DTCs are set, before attempting to diagnose other possible causes.
Driver Information Indicators and Messages
The following indicators are used to inform the driver of several different factors.
Brake Warning Indicator
The instrument panel cluster (IPC) illuminates the brake warning indicator when the following occurs.
The electronic brake control module (EBCM) detects that the park brake is engaged. The IPC receives a serial data message from the EBCM requesting illumination.
The instrument panel cluster (IPC) detects a low brake fluid condition and the IPC will illumination the brake warning indicator.
The IPC performs the bulb check.
The EBCM detects an ABS-disabling malfunction which also disables electronic brake force distribution (EBD) and sends a serial data message to the IPC requesting illumination.
Stability System Indicator
The IPC illuminates the stability system caution indicator when one or more of the following conditions exists. The EBCM sets any one of many VSES-disabling DTCs. The EBCM sends a serial data message to the IPC requesting illumination.
Monday, August 30th, 2010 AT 7:54 PM