Two-Way Radios - Poor Performance

File In Section: 9 - Accessories

Bulletin No.: 43-90-14

Date: January, 1995

Subject:
Stepper Motor Cruise Radio Frequency Interference (RFI) with Low Land Mobile Band Radios (Replace Module)

Models:
1995 Buick Skylark
1995 Chevrolet Beretta, Cavalier, Corsica
1995 Oldsmobile Achieva
1995 Pontiac Grand Am, Sunfire
(Fleet vehicles only - see below for complete list)

Condition
Some fleet customers may comment on poor performing two-way radios.

Cause
Radio frequency emissions are produced by the Stepper II cruise control module when the vehicle ignition is on. The emissions are in the 30 - 50 MHz band, which is referred to as the Low Land Mobile Band Radio. This band is used by businesses and government agencies for communication using two-way radios which are installed as after market options.

This interference reduces the audio quality of the reception in the vehicle and also reduces the range at which the vehicle can receive communications. The typical land mobile user in a vehicle can communicate with a base station at a maximum range of approximately 65 miles with no interference.





The chart illustrates the effects for each platform:

The fleet vehicles that will be affected by the Stepper II module are: Forestry/Conservation, government (local, state and federal) petroleum, fire departments, and taxies. This condition does not affect rental fleets or any other fleet vehicle not mentioned.

Correction
A cruise control module, P/N 25162818, has been designed that reduces interference with the Low Land Mobile Band Radios. Fleet vehicles with the new cruise control module may be ordered on a limited basis until January, 1995. After January, 1995, the revised cruise control module will be installed in all vehicles intended to be built with the cruise control option (K34).

Parts Information

Parts are currently available from GMSPO.

Warranty Information





For vehicles repaired under warranty, use: