So I got stuck in my driveway today, on the coldest day yet, radio said -49*C including the windchill, ouch!

anyway, i knew something was bound to fail, and something did, kinda of funny just because i called it.

Tried to put it in 4hi, blinked once and it didnt shift, pressed it again did the same thing. Finally the 3rd time the light stayed on 4hi, hit the gas and nothing, just rear tires.
put it back in 2hi no problem, put it in neutral hit 4lo and 2 or all 3 lights flashed 4 or 5 times then the 4lo light stayed on and i crawled right out.

also all the lights went out, i was like wtf, so i hit 2hi and it came back on

moral of the story being, 4 hi dosent work, yet 4lo does. I dont get any clicks/blinking not even a sound if I push 4hi. but when i push 4lo it blinks 4 maybe 5 times and then works fine.

from my searching its either
the encoder motor (just got quoted $205, and $274 for just the part)
or the dash board switch($?)
or i just need to reset the tccm disconnect the battery

but is there a seperate fuse that might be blown for the 4hi causing it not to blink or anything?

1998 GMC jimmy 3 button

 

Start here:
OBD2 NV233 Diagnostics

Then take a look at this:
NV233 No Mode Switch (ie. 2HI to 4HI)

 

ya those links dont really help me at all. why cant someone just say, oh this or this needs to be replaced....im probably not doing this repair myself, so i just need to know what failed, not a million steps to narrow it down.

 

Never mind the fact that those threads tell you how to identify what's wrong through actual diagnosis... This is a DIY site. If you aren't willing to DIY anything, why even bother posting? Can't help someone who doesn't want to help themselves.

 

Throwing money at it, you have three choices.
From the cheapest to the costliest:
Button switch assembly on the dash: ~$40.00 on ebay. $60.00 at Autozone.
Transfer Case motor. $160 ebay (brand new) $250.00 Autozone.
I don't believe this to be your problem, as you can shift from 2hi to 4lo. The motor is spinning and shifting the transfer case.

TCCM. anywhere from $100 used to $385 new (on ebay).
This is what I suspect your problem is. Do you hear clicking from the passenger side kick panel area when you select 4Hi?
You must hear clicking when you select from 4 lo to 2hi if indeed that is working properly. Perhaps a relay has dropped out/lost power on the TCCM board.

All prices will be less for the 3 button switch. Prices I searched when I replaced my 4 button TCmotor (NP8)

One thing you might want to verify is, put it in 4hi and wait for the lights to drop out. Then take it to a shop to diagnose the error codes (service 4wd light should be on). Should cost less than $100.00 to have it diagnosed.

There's a fuse for the 4wd, but if it was blown, nothing would light up or work.

 

Thanks for the info, but im not a technician, going for more of a redneck approach, besides, its -43 outside, not all of us have fancy garages, tools, and dmm's.

Sorry that some of us come here looking for advice and help for free, in an otherwise, unhelpful world.

I didnt realize that to post, and be part of Blazerforum that you had to be able to perform any procedure on your vehicle in any weather condition, my bad.


thanks for that post, my tccm was replaced 3 years ago, i believe it clicks for 4lo but not a thing when i hit 4hi. I'm thinking that because i tried 3 times in a row to engage 4hi it possibly put itself in a safe mode? is that possible?

windchill of -40 today, too cold to mess with my battery.

when my tccm failed the first time it wouldnt let me switch it at all. light was on 4hi, but was actually in 2hi and wouldnt let me switch, no blinks or clicks.

 

You really don't have any excuse for not having a multimeter if you really are interested in working on your vehicle. A dead nuts simple one can be purchased for $20 or less.

What TouringMike said was EXACTLY what I said through the links I provided had you been bothered to read through them. Checking codes - Link #1 for the procedure. Diagnosing the condition - Link #2 details how to check the switch, wiring, and diagnose a problem with the TCCM all with a simple multimeter. Exact same thing. Shesh. Reading comprehension fail? Or was it just that you couldn't be bothered with clicking on the links?

People can't just say "replace this" because they would just be guessing and you may replace the wrong component wasting your time and money. Problems need to be diagnosed and just because a part was replaced recently (3 years isn't recent) doesn't preclude it from being at fault.

The second link I provided details the three possibilities (switch, wiring, and/or TCCM). So right there that narrows it down for you. Hardly useless if you had bothered to read it. And there were what, 10 or so steps in that diagnostic tree... No where near a 'MILLION'... Anything can be made out to be much harder than it actually is if you don't want to do it.

You don't have to be a technician to follow simple directions with the information provided. And the weather conditions are immaterial since you can do the work in your truck with the engine running and the heat on. Use that thing between your ears!

 

I have no intentions on performing this repair myself, like i said, reading comprehension fail?

I have no interest in chasing down electrical related problems, but thanks for the lecture.

 

Yep, again on your part... Memory not so good either?

"probably" sounds like you really haven't made up your mind yet... And this wasn't until after you had so quickly dismissed the information I provided which did tell you what could have failed. Your original post didn't mention anything about who was going to do what...

Good to know. Thanks for clearing that up. I'll remember that for the next time you ask others to put time & effort into helping you with your problem when you really aren't interested. And you are welcome.

 

if you really thought id sit here for hours deciphering wiring schematics and diagrams, locating harness' and CTSY LP fuses ( id dont even know what the f*** that is) you must be crazy. I'd need to sit in front of an automotive terminology dictionary for hours before i started, you need to realize some people come here for guidance and advice, not technical diy's that obviously takes a fair bit of electrical knowledge to accomplish.

probably meaning i can disconnect the battery, not probe pin 16a,on harness 47, cycle ignition 5 times, step on the brake blah blah blah, too much work, and too confusing.

I mean, you must admit this is a bit above a beginners level, but yet you still feel the need to be a d**k about it.

in my original post you can see i was looking for the possibilites which it could be and rough prices, yet you just assumed i was doing it myself.

TouringMike got the idea, dont know what you found so difficult about it. hope your done your spaz now.