Regarding mechanics and electronics, have yet to meet any with any kind of electronic training, here is the latest example.
A good friend with a WV Golf cruise control quit working, took it to his VW dealer, said they checked everything and the problem has got to be the ECU, wanted 1,300 bucks to replace it, already charged him 450 bucks for diagnostics.
First question I had, does your speedometer work and does your AT shift right, said yes. Was told some kind of signal is missing, so can't be the Vss. Neck question, what about your gas pedal, does that work okay, does have throttle by wire, and the same exact output is used by the cruise. Only difference is that throttle voltage is converted into digital and stored into RAM, by command from the cruise switch, interrupted by the brake switch. Also by the cruise switch with on-off and a button, but still need continuity from the brake switch. They said they checked all this, but how?
So I found him a used ECU from a cruise working vehicle for 150 bucks, took it to his dealer charged him another 200 bucks, if you are keeping track, 800 bucks already, and the cruise is still not working. So now saying must be a wire someplace, but they claimed they already checked it. Told my friend to bring his car over, let me look at it.
With all this new BCM crap, can't think of a better word, the switch contacts have to be perfect, Cruze trunk switch is a good example of this, its a dry circuit? Meaning no arcing current flows. Also a point contact, doesn't take anything to corrupt these switches. Cruise is even more finicky, has fixed resistors that send different voltages to the ECU, if slightly off, nothing works. Even doing a net search on this problem cruise control switch was the major problem, only a few had brake switch problems.
But dealing with mechanics that have zero electronic training.
Ha, when I got into my old motorhome that used a memory solenoid with an arcing current didn't work after sitting all winter long. Worked that slide switch several times, then worked fine all summer long, self cleaning contacts and an arc current. You don't have this luxury with a BCM. Everything has to be perfect.
Should be getting in my new ignition relays in today or tomorrow, can't wait to compare these with the piece of crap that came with my Cruze. Just more problems.