Fuel - Incomplete Fuel Fill
Bulletin No.T 85-22File In Group 6C
Number 90
Date Nov. '84
SUBJECT: INCOMPLETE FUEL FILL
MODELS 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 18.0 gallons, whereas the actual fill levels being experienced are approximately 16.6 gallons. The digital fuel gauge displays "F" only when the actual fuel level is 16.6 gallons or more. Consequently, the fuel gauge may never indicate "F" or will indicate "F", but will drop to 16 gallons in a very short time.
A two-step production change is being implemented to affect fuel gauge calibration and assure the usable 18.0 gallon fuel capacity. These changes are as follows:
1. A BCM PROM change, effective at B.P. 204626, was made to provide a revised fuel gauge calibration. As revised, the fuel gauge display will show an "F" until the fuel level drops to 15.5 gallons at which time 15 gallons will be displayed. This BCM PROM (PROM I.D. 11, Broadcast Code DDM) is available through GMWDD 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 18 gallons 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.