Introduction To Cruise Control System Diagnosis

The cruise control system allows driving without stepping on the accelerator pedal by setting a random speed 40 km/h (25 mph) or more. Malfunctions in this system can be investigated by the following methods.

Cruise control system diagnostic trouble codes 

The cruise control system consists of the engine control module (ECM), control switches and sensors. The switches and sensors monitor the state of the vehicle. The ECM controls the throttle valve opening angle in the throttle body in accordance with the input signals from the switches and sensors. If the ECM detects a malfunction on any of those components, the ECM estimates where the problem may be occurring, and will set a diagnostic trouble code. Diagnostic trouble codes cover the cruise control switch, stoplight switch and ECM.