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

[Mightiestmike]

Well, I'm not sure I fixed the problem, but I got it back in 2HI, I put the truck in 4LO, and drove out of my parking lot to the street which is sloped, then I drove the truck in reverse at about 15-20 km/h to the top of the hill, then popped the truck into neutral and as it was rolling back down the hill press the 2HI button and it shifted right away.....

Found a solution, but don't know why.

[MT-2500]

Originally Posted by Mightiestmike

HELP! I am having the EXACT SAME ISSUE! I could swear I could have wrote the description to the problem!

This is my First 4x4 vehicle and I don't know too much about it.

The one thing that worried me about what i've read is, "Don't drive on dry pavement in 4W?" why not? I've never been told anything about this... I don't make it a habit to drive on dry pavement in 4W as it is quite un-necessary, but it happens when there is a part of the road that is dry, or plowed well... what can that do to the truck?

How did loots42 fix his truck?!

Please Help.

Loots did not say.

Best to start your own New -Thread.
Saves on hy jacking someone else's thread.
Give all info on your truck and problem and what transfer case you have.
And someone will help you.

[loots42]

I believe its the transfer case shift motor (encoder). I hear it trying to shift from 4 to 2 (although I'm still not sure from the discussions I've read nor this thread that there is actually a mechanical shift of disengaging the gears in the transfer case when you shift from 4HI to 2HI).

So my problem is not fixed yet.

[loots42]

I took the shift motor off today. I supported it with the wires still attached. The truck was in 4LO wen I took the motor off. As I press the shift button to 4H, I can see it turn from the lo possition to the high position. And then when I press the 2HI, it shifts in the exact same manner as when selecting 4HI. What it does is tries the shift twice. Since It isn't actually hooked up to the Transfer Case, it defaults back to 4LO.

So can I conclude it's not the transfer case motor? Any other ideas for this problem?

[MT-2500]

Originally Posted by loots42

I took the shift motor off today. I supported it with the wires still attached. The truck was in 4LO wen I took the motor off. As I press the shift button to 4H, I can see it turn from the lo possition to the high position. And then when I press the 2HI, it shifts in the exact same manner as when selecting 4HI. What it does is tries the shift twice. Since It isn't actually hooked up to the Transfer Case, it defaults back to 4LO.

So can I conclude it's not the transfer case motor? Any other ideas for this problem?

Proper testing will give you the answer.

Check for codes.
Get the all data sub to guide you along.
AND HELP YOU OUT.
http://www.alldata.com/products/diy/index.html

GOOD LUCK

[99BlueBlazer]

Hello - I hope this helps:

I drive a 99 Blazer. I have the exact same problem, but here is what I discovered that seems to solve the problem: Let the truck sit in neutral before going back to 2HI. I can shift into either 4WD ranges fine sitting at a complete stop in park or drive, but the only way I can get back to 2HI is by going back to neutral first. I don't know if it is supposed to be like this as the push button 4WD system is quite different than what I had on my 83 CJ7!

Good Luck!

[MT-2500]

Originally Posted by 99BlueBlazer

Hello - I hope this helps:

I drive a 99 Blazer. I have the exact same problem, but here is what I discovered that seems to solve the problem: Let the truck sit in neutral before going back to 2HI. I can shift into either 4WD ranges fine sitting at a complete stop in park or drive, but the only way I can get back to 2HI is by going back to neutral first. I don't know if it is supposed to be like this as the push button 4WD system is quite different than what I had on my 83 CJ7!

Good Luck!

Good suggestion. 99BlueBlazer
Yes that is normal.
Tires not matched or operating in 4W on dry payment adds to the problem of shifting back out of 4W.
On Some it also helps to back up or let it roll back some.

[loots42]

When I had the TC shift motor off, I put an open end wrench on and was able to shift to 3 distinct positions just fine and easily using the 14mm wrench. So I'm pretty sure at this point that it's not a mechanical problem of binding with the TC.

I put it back on and it still only shifts between 4LO and 4HI, but not to 2H. After trying to shift about 50 times, it'll then shift to 2H.

MT-2500 - the 4wd light is not on. The Chilton manual I have say I must have a OBDII scan tool (I know the cheap ones won't read tc codes), and does not outline the procedure manual procedure to ground the test terminals to get flash codes. Is there another way to get the codes?

[MT-2500]

Originally Posted by loots42

When I had the TC shift motor off, I put an open end wrench on and was able to shift to 3 distinct positions just fine and easily using the 14mm wrench. So I'm pretty sure at this point that it's not a mechanical problem of binding with the TC.

I put it back on and it still only shifts between 4LO and 4HI, but not to 2H. After trying to shift about 50 times, it'll then shift to 2H.

MT-2500 - the 4wd light is not on. The Chilton manual I have say I must have a OBDII scan tool (I know the cheap ones won't read tc codes), and does not outline the procedure manual procedure to ground the test terminals to get flash codes. Is there another way to get the codes?

Go back and read post no 4.

When you get codes post back code no.

For good repair info.

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

[loots42]

I grounded terminal 13 and it reported no codes. The truck is currently in 2HI, and when I ground 13 and turn the ignition on, no lights blink on the 4wd switch. So no codes. Hmm.

[djd99]

Originally Posted by Mightiestmike

HELP! I am having the EXACT SAME ISSUE! I could swear I could have wrote the description to the problem!

This is my First 4x4 vehicle and I don't know too much about it.

The one thing that worried me about what i've read is, "Don't drive on dry pavement in 4W?" why not? I've never been told anything about this... I don't make it a habit to drive on dry pavement in 4W as it is quite un-necessary, but it happens when there is a part of the road that is dry, or plowed well... what can that do to the truck?

How did loots42 fix his truck?!

Please Help.

It sounds to me that a good start would be replacing the vacuum switch on the transfer case.

[MT-2500]

Originally Posted by loots42

I grounded terminal 13 and it reported no codes. The truck is currently in 2HI, and when I ground 13 and turn the ignition on, no lights blink on the 4wd switch. So no codes. Hmm.

Are you sure you grounded pin 13?
With pin grounded.
Do they all come on and go off for the key on bulb check?

With pin 13 grounded do they all come on and go off for the bulb check?

[loots42]

I'm pretty sure. Count 1-8 on top row, and start with 9 on lower row on the left. I had a thin piece of wire that I shoved into the pin 13 terminal, and then grounded the other end to the emergency brake bracket. If I ungrounded it, the lights lit up as usual. When I grounded it, no lights on the 4wd switch light up.

[MT-2500]

Originally Posted by loots42

I'm pretty sure. Count 1-8 on top row, and start with 9 on lower row on the left. I had a thin piece of wire that I shoved into the pin 13 terminal, and then grounded the other end to the emergency brake bracket. If I ungrounded it, the lights lit up as usual. When I grounded it, no lights on the 4wd switch light up.

Do all 4W lights come on for a bulb check when key is turned on and then go off?

[loots42]

Without grounding pin 13, yes