!993 S10- Help with 4WD

I have a 1993 S10 4wd extended cab. I really have 2 problems. Let me start with the 4wd. It has a pushbutton 4wd. When I press the high 4wd button nothing happens no matter what gear I am in, even neutral. When I put the transmission in neutral and press the low 4wd, I can hear something switch and both indicator lights, the 4 low and 4 high come on, but still truck is not in 4wd.

The second thing is I checked for error codes and got a 12 which means according to the manual that I need to replace the ECU, which I suppose is the ECM. Could the ECM have an affect on the 4wd? Does anybody have any ideas? Your help would be appreciated.

Don't know if this will help you or not. Disconnect your battery for a minute or two, this clears the four wheel drive computer. A friend of mine at the Chevy garage told me about it (worked for me) they charge $85 . I believe code 12 means everything is ok.

I have a 1993 S10 4wd extended cab. I really have 2 problems. Let me start with the 4wd. It has a pushbutton 4wd. When I press the high 4wd button nothing happens no matter what gear I am in, even neutral. When I put the transmission in neutral and press the low 4wd, I can hear something switch and both indicator lights, the 4 low and 4 high come on, but still truck is not in 4wd.

The second thing is I checked for error codes and got a 12 which means according to the manual that I need to replace the ECU, which I suppose is the ECM. Could the ECM have an affect on the 4wd? Does anybody have any ideas? Your help would be appreciated.

key on, engine off got a 12? that means everything is ok.

as for the 4x4 nonsense, sounds like the little motors and gizmos that actually perform the shift are kaput. there are 2 - on on the xfer case to engage the planetary, another on the transaxle to slide the collet

the one on the transaxle is the one that actually turns on the various lights, so it sounds like the xfer case is the one who is slow

there is also a box that is under the dash that has 7 wires runnin to the trasmission that controls the 4wd (we had to fix a blazer that was doin the same thing at trade school)....do a trouble code test on the 4wd system by finding the wire in the obd that goes to the system (orange wire somewhere in it) when you do all the shift buttons will light up in intervals telling you your trouble code....there are only 4 codes so its pretty easy. to clear them....you have to take out the #3 park light fuse for 40 sec. and cycle the key on-off 5 times.

Ya 12 means nothing, the 12 is the start and end code on GM cars. If your check engine light isn't on, dont worry about anything. You should only check the codes if the engine light comes