98 Jimmy stuck in 4WD - Can't go to 2HI

[MT-2500]

Originally Posted by loots42

Without grounding pin 13, yes

Yes
And the try it grounding pin 13.
http://www.troublecodes.net/OBD2/

[loots42]

With grounding 13, no lights on the 4WD selector illuminator, nor blink

[MT-2500]

Originally Posted by loots42

With grounding 13, not lights on the 4WD selector illuminator, nor blink

What do they do if you do not ground it?
Does all button lights come on for a bulb check and the go out when key is turned on?

[loots42]

Yes, when I turn it on, all lights, dash and 4wd selector go on. Then when I start it up, the dash lights go off, and the proper 4wd switch light is illuminated.

[MT-2500]

Originally Posted by loots42

Yes, when I turn it on, all lights, dash and 4wd selector go on. Then when I start it up, the dash lights go off, and the proper 4wd switch light is illuminated.

The key question is
Does all 4W buttons light up for the key on bulb check and then go out and then show you what gear it is in?

You need to get some good repair info on it like a factory repair manual or the all data on line sub for one year one car sub. about 26.95$ usa plastic.
http://www.alldata.com/products/diy/index.html

The all data on line sub will take you step by step threw the testing process.
Good luck

[loots42]

Yes, all the 3 lights (2H,4H4L) light up momentarily, then 2 of the 3 go out. It is left showing which range the truck is in.

[MT-2500]

Originally Posted by loots42

Yes, all the 3 lights (2H,4H4L) light up momentarily, then 2 of the 3 go out. It is left showing which range the truck is in.

Ok.
If the lights do not come on for bulb check with pin 13 grounded.
You need to get the All Data sub and go threw the repair flow chart for that problem.
It will led you threw the repair step by step.
Good Luck

[loots42]

Ok, after grounding pin 13, all lights go on momentarily, then go out and none come back on. So no code is thrown.

I did discover that when stuck in 4wd, if I repeatedly, and quickly shift back and forth from 4Hi to 4Lo, it will jump into 2H.

[MT-2500]

http://www.alldata.com/products/diy/index.html

[loots42]

I subscribed to alldata.com. It did not have a use case for the problem I had.

I suspected it was the encoder motor, but started with the TCCM from a junkyard for $50. That wasn't it. So I bought a rebuilt encoder motor ($125)and now if shifts beautifully.

[MT-2500]

Originally Posted by loots42

I subscribed to alldata.com. It did not have a use case for the problem I had.

I suspected it was the encoder motor, but started with the TCCM from a junkyard for $50. That wasn't it. So I bought a rebuilt encoder motor ($125)and now if shifts beautifully.

Thanks for posting back the fix.
Glad you got it fixed.

The All data should have all of the repair flow charts and test for it.
It is the same as factory repair manual.
But sometimes the info is hard to find in there.
If you can not find the info contact all data and they will help you find it or send the info to you.
They are very good at helping you.

Good Luck