Curve Control

The ABS module continuously monitors the vehicle motion relative to the intended course. This is done by using sensors to compare the steering wheel input, the yaw rate sensor input, the lateral acceleration sensor input and the longitudinal acceleration sensor input with that of the actual vehicle motion. On vehicles without active park assist, steering wheel angle information is calculated by the PSCM and is sent to the ABS module over the HS-CAN2. On vehicles with active park assist, the SCCM sends the steering wheel angle information to the ABS module over the HS-CAN2. The RCM sends yaw rate sensor and lateral accelerometer information to the ABS module also over the HS-CAN2. If the ABS module determines from the inputs that the vehicle is experiencing over-steer or under-steer, the ABS module modulates brake pressure to the appropriate brake calipers by opening and closing the appropriate solenoid valves inside the HCU while the hydraulic pump motor is activated. At the same time, the ABS module calculates how much engine torque reduction is required to help stabilize the vehicle and sends this torque reduction message to the GWM over the HS-CAN2 which relays the message to the PCM over the HS-CAN1. The ABS module also sends a curve control event message to the GWM over the HS-CAN2 which relays this message to the IPC over the HS-CAN3. When the PCM receives the torque reduction message, it adjusts engine timing and decreases fuel injector pulses to reduce the engine torque to the requested level. When the IPC receives the vehicle stability event message, it flashes the stability-traction control indicator (sliding car icon).

The curve control function does not operate with the transmission in REVERSE. The ABS module disables the curve control function if there are any wheel speed sensor, stability sensor or steering angle sensor Diagnostics Trouble Codes (DTCs) present in the ABS module. Also, if there is a communication error between the ABS module and the PSCM, the SCCM or the RCM, the curve control function is disabled. When the curve control function is disabled, the ABS module sends a message to the GWM over the HS-CAN2. The GWM relays this message to the IPC over the HS-CAN3 to illuminate the stability-traction control indicator (sliding car icon).