4.0L GEM questions

[BigRigDriver550]

ive got a few questions regarding the GEM module in my pickup. It is a 2000 B-4000 SE 4.0L 5spd.

Ill start here. i replaced the transfer case about 4 months ago. it had a bad bearing in the tailshaft. up until that point, the 4x4 worked flawlessly. after the install, i buttoned everything up. when i put my shift motor back on, lowered the lift, and went to try it out, nothing happened. fast forward to now. i had a few buddies give me a hand looking at it. we had no power at the shift motor. we worked our way backwards with a meter and after 3 hours or so of tracing wires grounding out wires etc etc we came to the conclusion that the GEM was no good.

i called the local dealer and they told me they could order me a new one to the tune of 370 dollars. The only problem was it was about 5 weeks out. cant wait that long. The service tech i spoke to told me to find a GEM out of a junk truck. well i did just that. he went on and told me they dont have to be flashed or configured or anything of that sort. when i installed it eariler today, i hooked the battery back up and fired the truck up. idled nice, windows worked, inter. light works. but the 4x4 lights are flashing. they flash 6 times and then stop, flash 6 then stop, etc etc.

I went to take the truck for a ride down the road, and this is where it gets weird. the speedometer cranks right up to max and the truck just cuts out. only going around 5 mph. put the old GEM back in, it ran mint.

anyone ever run into this? im at a total loss right now. any input would be appreciated. sorry about the wall of text.


*EDIT
My truck is a 2000 mazda B4000, 4.0 5 speed, power windows. the GEM came out of a 99 Ranger, 4.0 5 speed, crank windows. the part numbers on the GEM are almost identical. the ranger GEM starts out as "XL5T-14B205-EC" and my GEM starts out with "YL5T-14B205-EB" all the plugs are identical. if thats of any help.
-Jim

 

[MrRangerSir]

Tech left out an important tidbit. The GEM will not require reprogramming if the application matches exactly. Chances are, the one you got does not.

 

[BigRigDriver550]

Ahh. i see. so in theory this GEM will work if i bring it to the dealer and get it programmed?

 

[Earl43P]

You have 4WD.

Was the GEM donor 4wd?

The difference is that with 4WD, you have 4WABS.

2wd did not get 4WABS. Why does that matter to the GEM?
4WABS uses the VSS on the rear axle to feed the 4WABS module.
The 4WABS module electronically conditions the raw VSS speed signal and feeds that "conditioned signal" to the GEM, speedo, Cruise and PCM.

2wd/RABS does the VSS signal conditioning in the GEM.

I can e-mail you wiring diagrams if you private message me your e-mail address. It'll show you that the 4wd and 2wd GEMs are wired differently.

You did not describe the symptoms when your GEM is installed and 4Hi or 4Lo is selected.

If you Google your part number (YL5T-14B205-EB), there are quite a few available for about $100.