Verify Customer Concern

Before performing speed control diagnosis, the customer concern should be verfied. Occasionally, the customer does not completely understand operation of the speed control system. If this is the case, the customer should be referred to the Owner Guide for complete speed control operating instructions.

Most misunderstanding involves operation of the RESUME feature. RESUME should be used to return to a previously set speed after speed control operation has been interrupted. The RESUME feature will not operate if the vehicle speed has been lowered through use of the COAST button. The release of the COAST button sets the new lower speed into the control memory. Also, RESUME will not work if the system is turned off with the OFF button. The OFF button erases the speed memory. The RESUME function will not work if the vehicle speed is below the minimum speed control operating speed of about 30 mph (48 km/h).

The RESUME function for the Stand-Alone Speed Control System may not activate with a momentary tap of the RESUME button. The RESUME button must be held down for a short time to make sure of engagement.

Speed drops of more than 1 or 2 mph may occur while in speed control operation on grades or under other load conditions. This is especially true on vehicles that are equipped with automatic overdrive transmissions or with manual 5 speed transmissions. These speed drops are due to limited engine power available in the overdrive (or the highest gear of a manual transmission) mode of operation. Under heavy load conditions, such as hilly or mountainous areas or during trailer tow, the vehicle speed may drop even more. When speed drops of 10 - 13 mph (16 - 21 km/h) occur the speed control system will, by design, automatically disengage.