Hi, let me first introduce my self, I am a private mechanic, (only work on friends and family vehicles now) I have a degree in automotive and I am a ASE master tech as well as worked in a import shop for four years. this is my girlfriends car so for personal and financial reasons I really want to get this car fixed correctly. It so happens that her sister has the exact same car, so i have been able to test and swap parts to my harts content, but to no a vale.

when i crank the car up when it is stone cold AC off within 10-20 seconds the cooling fan comes on full blast. I have been able to hook the car up to my scanner to read to coolant temps, they start out at ambient temperature and slowly climb to operating temp ~185f. I then proceeded to check resistance between the fan module and the ecu, and it checked out. I then checked the control voltage from the ecu to the fan module and it was almost 0.0 volts. after much forum trolling I concluded that the ecu had to have not been sending the signal; so I sent the ecu off to ecu tech to have it reconditioned. $800 later, I still have the same problem. what can i be missing here? i tried swapping the k40 relay, and fan module from her sisters car. I also have become aware of a oil temp sensor that is part of the oil level sensor, could this cause my issue? please help me before i drive this thing off a cliff.

 

Have you tried pulling off the fuse that controls the cooling fan and check if the fans turned off?

 

just tried it, and it did turn off, but it came back on immediately as soon as I screwed it back.

also i just plugged up a new oil level sensor, didnt change anything.