So I have owned this s10 for like 6 years and I have had no real trouble with it. I gave it to my fiancé about a year ago and soon after the truck started throwing the p1875 code and would go away every other day and the truck would be fine. The light goes out on the floor 4x4 shifter when it happens. So lately it has been nonstop and the light hasn’t come back on and I just am preparing to try to figure it out, the car needs to be inspected in November so I have time but I have gone through all of the posts about it and honestly I don’t understand much of it. I checked all the wiring to the TCCM and it seems to be fine, I unhooked it and everything is the same as normal. The 4x4 works fine also, which I thought was weird, but since it’s a floor shift I guess that why. My real thought is that the module is dead. I have a 1997 blazer 4x4 and I haven’t looked but does it have the same TCCM? I was wondering if it does could I temporarily swap it into the 96 and see if that fixes the problem. Also if you have any thoughts about the problem let me know. I’m not bad with cars I just don’t know too much about 4x4, this is all a learning experience for me.

 

A quick search for that code will turn up quite a bit of information.

 

Thats what every post says. I searched and searched and was wondering about:

 

To be quite honest, I made it about half way through your original post and stopped reading because; A) it sounded like every other post lacking effort and B) it was absolutely HORRIBLE to read. Paragraphs man, paragraphs!

So let me get this straight... You have a floor shift NP231 and you also have a TCCM... That there just doesn't make sense.

The floor shifter is a mechanical linkage to the transfer case and does not require any electronics. The light in the floor shifter is triggered by the switch on the front axle and shows when/if the front axle engages.

Is it possible that someone has swapped out the NP233 transfer case for an NP231?

But that is all besides the point. A transfer case code should not cause an inspection failure.

 

If the CEL is active it fails. And its the floor shift 4x4. The light on the 4x4 display at the top (2wh 4wh N 4wl) goes out then the CEL sets in.

This truck was run for years with no problems and no work was done to the transfer case.

I must be mistaking the TCCM. Like i said i know nothing about 4x4.

So what would cause the light to go out(on the 4x4 shifter) and then the code to set in (and turn on the CEL)?

And sorry about the paragraphs but what could I have done, turned that into two paragraphs?

 

Oh and if you were confused, the regular shifter is on the Steering column not a floor gear shifter.

 

A followup to this problem that i was having, and i will explain again because of all the confusion from lack of paragraphs.

1996 S10 4x4. It had the p1875 code. It is an automatic with a column shift. The 4X4 is a floor shifter. The truck would shift like crap when the problem was occurring.

Symptoms:
The little indicator light that states 2 wheel high, 4 wheel high, N, and 4 wheel low when you shift would go out when the problem was occurring. NOT the light that shows that it is IN 4 wheel drive.

The FIX:
I checked everything underneath, all was well.
I then ripped the floor console off and took the handle off of the 4x4 shifter, there is a little staple like clip holding it on, then it slides off. Noticed that the wiring was crimped pretty well on one side. I straightened it out and it worked. I then checked all connections and found that it was just the fact that the wire was pushed and was making the contact disconnect on and off(more likely) or short out(less likely, no indications of shorts). (That's why the problem was intermittent.) I straightened out the wires. Made sure there was no cracks or breaks in the wires and put it all back together. Truck is fixed no more code, no more problems and the light is back on on the shift indicator.

170,000 miles and still happily kicking.