Hello everyone,

I just picked up a 2010 IS250 AWD with 48k miles yesterday. This morning I decided to inspect fluids and air filter cleaned the maf sensor, reset ecu. I did notice that the coolant was very low in the resovoir tank filled it up the correct mark. Then I just wanted to see if the coolant had air bubbles, and proceeded to let the car run idle. I used the lisle funnel to bleed the coolant. What I did see is that the cooling fan never came on. I had the heater full blast the temp gauge was a little under the half mark. The fan never kicked on.

So far I looked for the temp switch on the radiator couldn't find it to test the switch if it's working or not. The car drives fine fans do come on with AC. I do see that the fans do sound extremely quiet and underpowered compared to my GS400. Those things are noisy and blow like a Cat 5 hurricane.

Does the ECT control the fans on the IS250? Also at what temp should the fan kick on?

If anyone can chime in that would be great.

Thanks,

Mike

 

Did you ever figure out the fan situation?

 

Yes they were never faulty. I just didn't know they ECM controlled the fans. I was coming from a 98 GS400 it had the sensor on the radiator, and also ECT.

I'm assuming the IS250's ECT controls that function. Or how else world the ECU know the temp reading to operate the fans. If it doesn't have a thermistor on the radiator itself. Just my guess here.