so my '93 4 door 4 wheel drive may need an exorcist (sp?). my wife was driving itand she hit the 4lo button and couldn't get it back into 2hi. through some combo of back and forth with some profanity mixed in, it went into 4hi. I work at a towing service/shop and they somehow got it back into 2hi. well it started snowing and I wanted it back in 4 hi (the irony huh). and the button dosen't do anything at all. the shop said its not a vacum issue but somthing electrical.

I've been looking through alot of posts but I haven't seen this excact problem described. so what I guess I'm getting at is.....HELP!![sm=headbang.gif][sm=headbang.gif][sm=headbang.gif]

 

If theyre sure its not vaccum then the next electrical part is the TCCM. But you would first want to try cleaning out the switch contacts. Then check the TCCM

Was she moving when she put it into 4Lo?

 

I belive she was moving when she did it, where would I find and how would I test the tccm? hopefully this can be fixed relatively cheap, the snow is piling up out there and this is taking away from my new tire fund.

 

In 1993, GM replaced the 4x4 floor console lever selector with a electronic pushbutton 4x4 selector switch. GM was having problems with the1993 and1994-1997electronic 4x4 selector switchesand werethesubject for a major GM recall in 1998. It seems the4x4 switch error caused the ECM to send an incorrect signal to the ABS brake modulator and caused the pedal to go to the floor unexpectedly. At least that is what GM told the NHTSB during the recall hearings.Just like the1991- 1992 mechanical lever 4x4 selector, the1993 and 1994-1997 electonic selector button switch signals theswitchlocated on the front axle. Theearlier selector lever does not send a 2wd or 4wd signal to the ECM and to theABS brake modulator. Failure of the brakes on the earlier models is due to dump valve being stuck openin the controller itself.

GMeliminated the problems with the1990-1992 Kelsey-Hayes EBC4 4WAL brake modulator but created more problems with the 4WAL brakes when they introducedthe 4x4 electronic selector switch in 1993. By the time the 1990-1992 4WAL ABS modulator failed, the vehicle was usually out of warranty soGMmanaged to escapea more expensive recall. GMmade the lame excuse that the 1990-1992 4WAL brakes failed becausedrivers were unfamiliar with the new ABS system and did not know how to use ABS brakes.

Your problem does not seem to be effecting the 4WAL brakes but is a effectingthe 4x4 shift selectorcircuitry. Install anew 1993 Airtexselector switch is a Airtex #1S8505 ($37.00) and a Standard Motor Products #TCA6 ($15.00) front axle actuator switch.

 

Hopefully Duntov's suggestion works.

You should be stopped and in N to shift to 4Lo. 4Hi can be engaged at any time under something like 55 mph.

 

well as it turns out its a short somewhere, its way too cold to be working outside right now so I have the shop work on it while I'm at work (its towing/repair and I work on the towing side). so I guess it is kinda possesed.

is there any common place to look for a short for the 4wd?