I need a wiring diagram or complete description with signals and pin numbers for GMC Jimmy 4x4 98 transfer case and switching system. I have had it with this transfer case TCCM. I want to trace the signals and find out where and what is getting lost. If I can get this I will either find and fix the problem or design an alternate switch to replace this confounded TCCM. I need to know what signals the encoder motor is receiving and what is fed back to the TCCM to light the switch on the dash. If I do design a replacement I will post a diagram and complete how to whith details and pictures for a fix anyone can make to these compuerized night mares. I have the 3 button 2HI, 4HI and 4 LO switch and I believe the NP233 transfer case. I will check this post continually throughout the week and during the holiday. thanks to anyone who can help. In case anyone is wondering, yes I can rewire it around the computer. I have been working in the electronics field with troubleshooting and repair work for over 20 years including military and teaching. Give me the wiring diagram or schematic and I will either fix it or make it work. I wont pay over 400 bucks for a computer that has less than 50 dollars of comonents in it.

Check you PM e mail.

That is the easy part.

I think some of the signals are modulated electric signals.
You will need a lab scope to test and read on that part.

Also codes can be retrieved by grounding pin 13 on diagnostic connector.

But the specs on the signals may be may be a GM no information giving out deal.

For more information on testing a A good factory repair manual or
http://www.alldata.com/products/diy/index.html
Would help.
Also
http://www.automotiveforums.com/vbulletin/showthread.php?t=572914

If you want to tell us what yours is doing or not doing maybe someone can help.
Any codes?
Good Luck MT

I got it. I will need my reading glasses to see it, but it should work to at least get me started. I will try to get a manual as suggested for the signals themselves. Thanks. i will keep posted as I progress.

You are welcome.
10-4 on reading glasses.
I had to slim it down t go threw the mail machine.
I always have to enlarge the part I want to read.
And copy it off and save it to sometimes the web site goes down.
Good Luck
MT