Testing FICM ?

[legionxxii]

When testing the FICM does it matter if its cold or warmed up? I searched and some say warmed up and some say cold.

[Dirk]

If you see a voltage drop cold or hot, then it is bad. But, if the FICM is bad, how would you test it warmed up?

Remove it, toss it in an oven?

[Dirk]

Also, MAKE SURE your batteries are good. Test them off the truck. I've seen bad batteries cause people (even techs) to replace a FICM.

[legionxxii]

I worded that wrong I meant like if the truck is warm or cold

[Dirk]

OK, back to my original statement. "If you see a voltage drop cold or hot, then it is bad. But, if the FICM is bad, how would you test it warmed up? "

General rule, FICM goes out, you have a no start or a real hard start and you'll throw a code. And also as a general rule, if you see voltage drop, FICM is bad or about to have a quick death.

[supreme oppressor]

I say test it under the conditions that match when the problem exists.

The write-ups I have seen are for long crank times when cold, so thats when they recommend testing.

[legionxxii]

Ok ya when mine has set over night and I go to start it to leave for work it will start die and repeat a couple times then fire up. Then will run with like half power till warmed up. After that I can turn it off and start it with no problems till it sets for along time again.