CODE F41 OR B441 COOLING FAN FAULT INTERMITTENTLY

MODELS AFFECTED: 1985-1987 DE VILLES AND FLEETWOODS 1986-1987 ELDORADOS AND SEVILLES 1987 ALLANTE

Some 1985-1987 De Villes and Fleetwoods may have a condition of an intermittent cooling fan fault light on and a code F41. Some 1986-1987 Eldorados, Sevilles and Allantes may have a condition of an intermittent "Cooling Fan Fault" message on the CCDIC and a code B441. If these conditions occur, and the diagnostic tree in the Service Manual does not lead to the cause of this condition, use the following diagnosis.

Step 1 - Check for the proper fan control module. 1985 De Villes and Fleetwoods should have a fan module with part number 1632916 imprinted on the black plastic portion of the case. All 1986 and 1987 vehicles should have a fan module part number 1638574 or 1641400.

Step 2 - Check the fan control module ground connection near the starter. A loose or dirty ground connection near the starter may cause a false code F41 or B441 to set. . Step 3 - Check the cooling fan motors for excessive amperage draw. Disconnect the cooling fan module signal connector (circuits 790 and 791). Using an in-line or inductive ammeter with a 50 amp or lower full scale reading, measure the amperage draw of each fan motor while the fans are overridden at full speed. Use of an ammeter with a 50 amp or lower full scale reading will help ensure a reliable amperage reading. Consult the chart below to determine if a cooling fan motor is drawing excessive current:

Maximum Acceptable Cooling Fan Draw at Room Temperature

Model Year - Car Line Small Cooling Fan Large Cooling Fan --------------------- ----------------- ----------------- 1985 De Ville and Fleetwood 13 amps 13 amps 1986 De Ville, Fleetwood, Eldorado, 13amps 13 amps and Seville

1987 De Ville and Fleetwood 8 amps 14.5 amps

1987 Eldorado, Seville and Allante 13 amps 13 amps

If a cooling fan is found to exceed the maximum acceptable cooling fan draw, it should be replaced.

For warranty purposes, use Labor Operation J3400 at:

.3 hours for one fan .4 hour for both fans on De Villes .6 hour for both fans on Eldorados and Sevilles

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.