INCOMPLETE FUEL FILL NEW PROM P/N-REVISED GAS TANK

Vehicles Affected: 1985 FWD Deville and Fleetwood

Some 1985 FWD Deville and Fleetwood owners may experience what appears to be an incomplete fuel fill or inaccurate fuel gauge reading. As published in the Owner's Manual, the nominal capacity of the fuel tank is 68 litres, whereas the actual fill levels being experienced are approximately 63 litres. The digital fuel gauge displays 'F' only when the actual fuel level is 63 litres or more. Consequently, the fuel gauge may never indicate 'F' or will indicate 'F', but will drop to 60 litres in a very short time.

A two step production change is being implemented to affect fuel gauge calibration and assure the usable 68 litres fuel capacity. These changes are as follows:

1. A BCM PROM change, effective at B.P. 204626, was made to provide a revised fuel guage calibration. As revised, the fuel gauge display will show an 'F' until the fuel level drops to 59 litres at which time 57 litres will be displayed. This BCM PROM (PROM I.D. 11, Broadcast Code DDM) is available through PARTS as service P/N 16040601.

2. Effective at B.P. 237516, a production change will be made to the fuel tank vent tube in order to allow approximately 68 litres customer fill. There will be no service modification to existing tanks to increase usable fuel capacity. Should a replacement gas tank be required, the revised tank with a usable capacity of approximately 18 gallons can be obtained as service P/N 22529319.

General Motors bulletins are intended for use by professional technicians, not a "do-it-yourselfer". They are written to inform those technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions and know-how to do a job properly and safely. If a condition is described, do not assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See a General Motors dealer servicing your brand of General Motors vehicle for information on whether your vehicle may benefit from the information.