BMW X5 FAN not working...HELP!!!!
 

08 X5.
radiator fan should come on when temp is 203.
it does not.

below 203 i can turn the fan on with my scanner.
once above 203 i can NOT turn the fan on.
if i remove the connector from the temp sensor the fan comes on hi no matter what the temp is
if i turn on the AC the fan comes on very low.

i can monitor the signal from the ECU to the fan with my scanner.
with AC on it is at 11%. with the temp sensor NOT connected and fan on hi the signal is 100%
otherwise there is no signal.

with temp sensor NOT connected my scanner shows no temp.
with it not connected the temp OUT of the radiator does not change.


i sent the ECU to ECU pro. they tested it and had same results.
they cloned mine and same results.
this is odd- they did one from "virgin" software and same thing
they sent me a "replacement" and my car acts the same.
(they said i can send it back)

i am at a loss.
any ideas.

oh, no fault codes

Fan control module.

where would it be
been searching.
also searching to see if i have one.
there is a part that shows up but thought the ECU sent a PWM signal directly to the fan.

also. i dont see the command from the ECU to turn the fan on.

It may be built in to the fan unit. Try searching online if no one replies back here

08 X5.
radiator fan should come on when temp is 203.
it does not.

below 203 i can turn the fan on with my scanner. Communication with ECU is good. You are bypassing the Temp Sensor.
once above 203 i can NOT turn the fan on. ECU controls the fan, this should be a 3 wire fan, two thick wires, one thin as it has a feedback loop inside the fan motor thermal sensor.
if i remove the connector from the temp sensor the fan comes on hi no matter what the temp is. Circuit to ECU is good. Sensor is questionable since its a resistor circuit
if i turn on the AC the fan comes on very low.Communication with ECU is good. ECU regulates voltage to fan by Temp Sensor signal/ Temp Sensor suspect.

i can monitor the signal from the ECU to the fan with my scanner. Communication with ECU is good.
with AC on it is at 11%. with the temp sensor NOT connected and fan on hi the signal is 100% otherwise there is no signal. Temp Sensor suspect. Its a resistor working on high only.

with temp sensor NOT connected my scanner shows no temp. Exactly, circuit is interrupted.
with it not connected the temp OUT of the radiator does not change.


i sent the ECU to ECU pro. they tested it and had same results.
they cloned mine and same results.
this is odd- they did one from "virgin" software and same thing
they sent me a "replacement" and my car acts the same.
(they said i can send it back)

Just talking. Longshot. 2007 320ix. New electric water pump. Connection talked some to the ECU but could not get it to operate with full functionality.

The connector was at the bottom of the front of the engine. Seeping oil dripping down from the little oil cooler up top caused the rubber seal in the connector to swell not allowing the connector to seat properly. Bought a new connector and took the seal out and put it in the original connector. Worked.

However, I did spray a good deal of brake cleaner to clean the oil up and that may have caused the connector seal to swell. All other parts were replaced with OEM.

Don't laugh, but a similar problem has shown up on the Bullitt board. Fan not coming on with temperature, cause a burnt fuse box connection hidden under a fuse panel.. Just might be the same basic problem you have.

I had my car rewired as a preventive measure by the dealership's shop foreman...made it look good, like it was factory.
(edit) Pay extra attention to comments made by "mrt2you" in this thread.

https://www.imboc.com/threads/burnt-fuse-block-low-speed-fan.378530/