CODE F41 OR B441 COOLING FAN FAULT INTERMITTENTLY

CODE F41 AND COOLING FAN FAULT LIGHT ON OR CODE B441 "COOLING FAN FAULT" MESSAGE APPEARS INTERMITTENTLY

VEHICLES AFFECTED: 1985-87 DE VILLE AND FLEETWOOD, 1986-87 ELDORADO 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, 13 amps 13 amps Eldorado, and Seville

1987 De Ville and Fleetwood 8 amps 14.5 amps

1987 Eldorado, Seville, and 13 amps 13 amps Allante

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

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.