[Jeff Hail]

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)