Cruise Control: Description and Operation

The speed control system, performs control functions for setting or cancellation of fixed-speed driving based upon data provided by input signals. When the speed control system is cancelled, the cause is memorized in a separate circuit by the Electronic Control Unit (ECU) whether the condition is normal or abnormal. This provides the ECU with a self-diagnosis function by monitoring certain fixed patterns and is able to check whether the ECU input switch or sensor is normal. When using these functions time required for checking and repair can be shortened.