Lateral Acceleration Sensor

GENERAL
This new sensor is also a major contributor of the expanded capabilities of Dynamic Stability Control (DSC) III. This sensor too is located under the driver's seat but mounted on the vertical surface of the inner rocker sill (approximately 2" in front of the B pillar). The driver's seat and door jamb trim must be removed and the floor coverings pulled out of the way to accesses the lateral acceleration sensor.

SENSOR OPERATION
The lateral acceleration sensor is connected to the DSC III control module by a 3 pin plug. The sensor receives operating power and ground. In return it provides a linear voltage signal which is a measurement of "side to side" G-force acceleration.

^ The voltage range is from 0.5 to 4.5 volts which corresponds to a G force range of -1.5 to +3.5g.
^ With the vehicle stationary on a level surface, approximately 1.7 volts is present on the signal line. This is the 0.0g median value.

The sensor is a capacitive type sensor. Under the effects of lateral acceleration, a moving capacitor plate moves in relation to a fixed capacitor plate. The result is a signal proportional to the affect of lateral acceleration.

The signal provides additional information which enables the DSC III logic a higher level sensing the vehicle's handling characteristics. The DSC regulation is calculated from:

^ the steering input for the desired vehicle direction from the driver
^ the Rotational Rate sensor to determine the "yaw" of the vehicle
^ the left and right front wheel speed to verify the turning rate in the corner

These inputs allow the DSC logic to calculate the under/over steer while cornering, and the rate of the vehicle speed entering the corner. From this calculation, the DSC can then compensate by reducing engine torque, and applying the appropriate braking to stabilize the vehicle for safer handling.

SENSOR REPLACEMENT
If the lateral acceleration sensor is replaced, the new sensor must be calibrated with the DSC III control module through the DIS Service Functions.