GM Service Manual Online
For 1990-2009 cars only

NO FUEL GAGE DISPLAY W/D.I.C. REPLACE FUEL TANK GAGE

VEHICLES AFFECTED: 1985 Oldsmobile Ninety-Eight Equipped With Digital Electronic Cluster (U52)

Some 1985 Ninety-Eight models equipped with the digital electronic cluster (U52) may experience a condition of the fuel gauge going blank when the fuel tank is full. The gauge will start working after the fuel level decreases below full. This condition is caused by a combination of the tank gauge resistance too high (greater than 92 ohms) when the tank is full and the digital cluster resistance upper limit specification is too low (96 ohms).

If the fuel tank gauge resistance exceeds 92 ohms with the tank full of fuel, the gauge should be replaced. The new tank unit should not exceed 92 ohms in the full position. Units with a date code greater than 1055 (4-15-85) have been inspected.

If the fuel tank gauge resistance is correct and the instrument cluster fuel gauge is still blank, the instrument cluster should be removed for repair.

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.