Speed Control - Diagnostic Tips: Overview

90ford40 SPEED CONTROL - "TRICKS OF THE TRADE"
Article No. 90-25-12
FORD: 1986-91 CROWN VICTORIA, ESCORT, MUSTANG, TAURUS, TEMPO, THUNDERBIRD 1990-92 PROBE

LINCOLN-MERCURY: 1986-87 LYNX

1986-91 CONTINENTAL, COUGAR, GRAND MARQUIS, MARK VII, SABLE, TOPAZ, TOWN CAR

LIGHT TRUCK: 1986-90 BRONCO II

1986-91 AEROSTAR, BRONCO, ECONOLINE, EXPLORER, F-150, F-250, F-350, RANGER 1988-91 F SUPER DUTY



ISSUE: Integrated Vehicle Speed Control (IVSC) was introduced on some 1986 units. The IVSC system uses the EEC IV processor as the control module. Before IVSC a Stand Alone Speed Control System was used on all applications. The Stand Alone Speed Control System uses a separate control amplifier.

ACTION: Refer to the following diagnostic information when servicing speed control concerns. Refer to the Speed Control System Application chart to determine which type of system is used for a specific model.


NOTE: THE DIAGNOSTIC INFORMATION ON THE FOLLOWING PAGES WILL APPLY TO THE STAND ALONE AND INTEGRATED VEHICLE SPEED CONTROL SYSTEMS UNLESS A SPECIFIC VEHICLE TYPE IS REFERENCED.
"TRICKS OF THE TRADE"

Many speed control concerns can be easily resolved by using the following "Tricks of the Trade" diagnostics. If a concern cannot be resolved, refer to the shop manual, Section 37-05 for additional component testing.