Cruise Control Module - Engine RPM Fluctuatation

NO.:
18-17-92

GROUP:
Driveability

DATE:
Sep. 8, 1992



SUBJECT:
Engine RPM Fluctuates When The Vehicles Speed Control System Is Engaged



THIS BULLETIN APPLIES ONLY TO NON-INTERCOOLER DIESEL ENGINE POWERED VEHICLES (IDENTIFIED BY AN "8" IN THE EIGHTH POSITION OF THE VEHICLE IDENTIFICATION NUMBER).


MODELS:

1991 (AD) Ram Pickup/Ram Cab & Chassis


SYMPTOM/CONDITION:

Vehicles may exhibit engine RPM fluctuation when the vehicle speed control system is engaged at highway speeds. The road speed does not change. However, there is an audible noise associated with the engine RPM fluctuation. This condition may be caused by the calibration of the vehicle speed control module. Vehicles exhibiting this condition should have the following repair procedure performed.


DIAGNOSIS:

Test drive the vehicle with the speed control system engaged at a speed between 40 - 60 MPH. If the vehicle exhibits the condition described above, proceed with the following procedure.


PARTS REQUIRED:

1 Module, Vehicle Speed Control 4728464


REPAIR PROCEDURE:

This bulletin involves replacing the vehicle speed control module with a recalibrated module.

1. Remove the vehicle speed control module shown on page 8H-9 of the 1991 Rear Wheel Drive Truck Service Manual, Publication Number 81-370-1108.

2. Install the new module, PN 4728464.



3. Test drive the vehicle as described in the diagnosis section to verify that the engine RPM no longer fluctuates.


POLICY:
Reimbursable within the provisions of the warranty.


TIME ALLOWANCE:
Labor Operation No. 14-20-03-92 ...... 0.5 Hrs.


FAILURE CODE:
58 - Internal Defect