TSB 90-25-12 Vacuum Cruise System Diagnostics

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.

Owner caption January 2007 · Photo 1413 of 5000