Electronic Control Module (ECM)

ECM is located behind dash, above glove compartment. ECM constantly monitors and compares set speed with actual vehicle speed from input sensors. When vehicle speed is greater than set speed, ECM activates actuator motor to close engine throttle valve, reducing vehicle speed. As increased vehicle load causes speed to drop, ECM commands actuator motor to open engine throttle valve and maintain vehicle speed.

ECM includes a self-diagnostic function. If cruise control system is canceled by any condition other than driver operation, ECM assumes a malfunction has occurred and may set a corresponding trouble code.