Circuit/System Description

The haptic seats, also known as safety alert seats, provide a vibration to alert the driver in certain circumstances. There are two motors in the driver seat cushion. Either the right or left motor can run or both depending on the alert. The seat memory control module provides the output voltage for the motors. The seat memory control module receives serial data requests from other modules to activate the appropriate seat motors with the number of pulses requested. While the motors are activated, the seat memory control module checks for either shorts to voltage or shorts to ground. Due to the nature of the PWM signal, if a motor circuit is open, it may be reported as either a short to voltage or short to ground.