Code B441 - Cooling Fans Problem: Notes

Code B441 is set by BCM if it receives improper cooling fans feedback voltage. Cooling fans control module is designed to change feedback voltage on circuit No. 791 as follows:

• 7 volts if fans have been turned off.
• Zero volts if fans have been turned on.
• 7 volts if fans have been turned on and an excessive current draw exists (stalled or shorted fan motors).
• Zero volts if both fan connectors are open.

The BCM will set code B441 if either of the following conditions exist:

• The BCM has commanded fans off, but feedback voltage remains low. The BCM will keep code B441 current for rest of ignition cycle and continue providing a normal control signal to cooling fans control module. The BCM will again test this condition during next ignition cycle to determine if malfunction has become intermittent.
• The BCM has commanded fans on, but feedback voltage remains high. The BCM will command fans off to protect the system from possible stalled or shorted motor condition. If control temperatures (coolant and A/C high side) should drop below turn off points and later require the fans on, the BCM will repeat the test to determine if malfunction has become intermittent.

Both of the above conditions will result in illumination of "COOLANT TEMP/FAN" display on CCDIC whenever control temperatures require cooling fans operation.

1. The cooling fans override feature BS04 can be used to evaluate system operation. If either fan is off when high fans are commanded or if either fan is on when fans off is commanded, appropriate diagnostic path can be followed to isolate malfunction.
2. The cooling fans feedback input BI41 can be used to evaluate the feedback signal being received by BCM. If input does not agree with actual fans operation, circuit No. 791 must be investigated for possible malfunction. If input does agree with commanded fans operation within appropriate time period, then cause of code B441 is not currently present.