Thermo fan sensors
 

Hi,

Interesting issue happening. When I turn on ACC. with out starting car, my Main Cooling Fan or THermo Fan kicks on, I have noticed it been running all the time now. I have checked all the V7 Tables and looked at settings, and it should not be doing this based on duty and temp. However, also with in my xml definition on the 9417 ROM, I noticed (2) tables that talk about sensor fault and sensor fail... Its doing this with air temps of 60 degrees F or 15 degrees C. Very weird for it to do this. Maybe the fan relay is going out, for it is the stock unit from day one on the car...2004.

Can any one point me to what sensors the Main or Thermo Fan runs off of so I can check those sensors for fault? Common sense says Water Temp Sensor, but I can verify that it is reading, I would say rather accurately. I'm just trying to figure out why it is running all the time.

Thanks in advance,

Bump

Your control module is dead. I have a thread about it here:
https://www.evolutionm.net/forums/evo-electrical-audio-security/743349-radiator-fan-controller-bought-farm.html

Thanks for the heads up. How is yours working now that it has been going on for a year?

Your welcome :thumbup: I actually tested both speeds with evoscan a few weeks back and it worked no problem.

SMH, I always forget about the actuators in EvoScan...lol. DOH!

Haha yah they do come in handy for testing electrical circuits.

Hey Biggie, so I just did the actuator test, and both speeds work, though I haven't changed out the module? The fan that turns on when I turn key to accessory is the inside fan, or fan between radiator and turbo. Seems like the actuator turns on the fan between the bumper and radiator. What do you make of this?

Can you share your thermo fan duty tables ?

All stock, verified against 3 different stock roms. Also loaded stock 9417 and 9653, with no change.

Ok, just ran actuator test again. Fan between Radiator and Turbo, no change. Actuator turns on Fan between bumper and Radiator, though it sounds same speed with both High and low actuators, but does turn off and on with actuators.

If the main fan (the one between the radiator and turbo) always turns on with your ignition then its control module is probably toast (mine failed to a closed circuit). The other fan doesn't have a control module so i think its just a one speed controlled by an ecu triggered relay. The main fan operates off a PWM signal from the ECU.

I am sourcing one for test, I will get back to you. Thanks

It was the Fan Module. Picked on up from the local Mitsu Dealer today for they just happened to have one in stock. Cost me $250 but they owed me some credit for some trade work, so free 99.

Nice, 250 is painful but at least you know you aren't rolling the dice.

Sorry for bumping an old thread, but if I understand it correctly, bad fan control module can turn on the fan even the engine is not running?

I had a recall for the fan control module, but it was more like 15 years ago already (still under 60,000 miles on odometer though), and mine does similar things now,
it stays on even after engine is shut off, and when the engine is warm fan kicks on even before the engine start.
But it does not stays on, so I though my coolant temp sensor is going bad, but after reading this, I guess fan control module is the problem. :(