Is there a PMD/FSD test?

[signgrafix]

Is there any computer equipment out there (other than your truck) that will test your PMS/FSD to see if it is operating properly?

[Hubert]

I have never seen anything for the common man. I guess an electronics magician can test it with an oscilloscope and majic wand.

Not any easy tests I have seen. The Helm manual does have a crude no start flowchart that describes probing a few connections and/or something about unplugging optical sensor to force the solenoid into limp mode. Its fuzzy in my memory. And at the time of my manual publishing GM serviced the FSD by replacing the IP/FSD as an assembly. So the diagnostic flow chart mostly ended with replace IP if there was a problem. Looking back now seems like GM replaced a lot of good IP's for various missed diagnostics.

Most every post I have read its test by swapping out the FSD on truck.

[16gaSxS]

A crude test that may help is if can carry a small cooler with some iced water and you get a stall try pour ice cold water on the PMD/FSD. If you get a restart right away it MAY be your PMD. I was albe to limp home late one winter day using snow to cool the FSD.

[tommac95]

Most here remount FSD remote and carry a spare ... then can swap new with old to check. That's only check i'm aware of. Treat connector with care.

[moondoggie]

Good Day!

IMHO it wouldn't matter if there were a tester for the FSD. From years of reading here on the Page, plus my own personal experience (2 failed units), most fail intermittent anyway.

Blessings!