Originally Posted by pizzaguy

Based on a fourty year career in component-level electronics with an emphasis the first 28 years on automotive electronics, I disagree. It takes ONE heavy spike on the 12 volt feed to destroy a module(s). In 2016, I went to put up my top with the engine not running, the spike in the system from that big motor in the pump cutting out JUST ONCE, took out my airbag module.
What do you base your "Should" statement on?


First, that is one module, there are many others. Second, if the SKREEM fails, even with the "SKREEM delete", you are still going to have an issue. The "SKREEM delete" is not a total delete, it's just a mod that makes the ECU not ask the SKREEM for permission to start. You still would have no remote lock/unlock.


Easy.
1) With a cold engine, start car with A/C off. Fan must not run.
2) Turn A/C on, fan should run slow, about 100 rpm. Fan must run slowly.
2A) Turn the A/C off and observe that the fan stops. (Engine must be COLD, needle must be well below 1/2 mark for steps 1 and 2.)

Now do either 3 or 4:
3) Let engine heat, when temp needed gets to just above 1/2, the fan should start moving and speed up such that the needle never moves past the mark that the fan started moving.

4) Find the little gray wire going into the FCM, this is the bi-directional data line to the ECU.
4A) Cut the gray wire with wire cutters.
4B) These two things must happen:
.... The little "Radiator light" on the instrument panel comes on.
... THe fan, in about 15 seconds, ramps up to "warp speed" so fast and loud people look and wonder what you are doing.

If all the above happens, the module is fine. Until you cut the gray wire, the radiator light should not come on.

5A) Shut engine/key off.
5B) Using wire strippers and a "pink/red butt splice", splice the gray wire back together.
5C) Start engine.
5D) The radiator light" should not come on, and the fan should should not run unless the engine has heated up to about 1/2.

If all the above checks out, the FCM (Fan Control Module) is fine.