Re: GEM module? Got any wiring diagrams??
Yeah, It sure sounds like the GEM. And like you said usually it is caused by water damage. You should be able to open the GEM up and look at the circuit board also, see if you see and water damage.
You can probably get a wiring diagram from a online library, in Michigan we have it, but you have to enter you Michigan drivers license number to get in.
So the first thing I'd be looking at is too see if everything that is giving you problems is tied to the GEM, if so then it probably a safe bet that it's bad.
2015 Challenger HellCat Redline Red 8sp
1997 F350 4X4 CCLB PSD
2004 Jetta TDI
1999.5 Jetta TDI 11mm pump S7 PP764's 3bar MAP
1986 F350 CC Dually 6.9 ATS turbo lowered
1984 Mark VII 2.4 BMW Turbo Diesel
1970 Roadrunner 383 4sp
1970 Cuda 426 4sp Dana 60