Electronic 4x4 won't disengage

[Jimmy95]

I put my jimmy in 4 wheel drive during a cold snap (minus 23 deg. celcius) days later pressed the 2wd button and it just clicks, it won't go into 2wd or 4 low. The 2wd light flashes and then switches back to 4x4 light. With the engine off but key on, I can hear something up front under the hood making a humming noise, like it is trying to do something. Any suggestions

[Jethro_Canada]

What happens when the truck is neutral and then you press the 2wd button?

[Jimmy95]

Same thing Jethro. The noise I hear under the hood , down under the motor, sounds like a mechanical buzz, like some motor is turning or something. Same sound you hear when a old style Satelite dish or antenna is being mechanically turned. So I would think that it is not the switch in the dash but something under the truck.

[Jimmy95]

New update the mechanical motor noise I hear when the engine is off, but key is on, is coming from the transfer case. So what could it be?
Noise happens when 2wd buttom pressed.

[rockergrl]

Originally Posted by Jimmy95

New update the mechanical motor noise I hear when the engine is off, but key is on, is coming from the transfer case. So what could it be?
Noise happens when 2wd buttom pressed.

A high-pitched whine can mean the pinion gear and ring gear are set too tightly or one of the bearings may be bad. You might want to have that checked, also check the type of fluid and amount.

[Jethro_Canada]

Wonder if the encoder motor in the transfercase is stuck on, probably wouldn't hurt to try the battery trick. Works for me now and then, un hook the battery for 30 minutes. Maybe it will reset the logic on the encoder motor. I like the push button when it works, but my next truck if I ever get one will be a manual floor engage.

[Jimmy95]

Unhooked battery for an hour, still not working. Someone must know..the shift motor on the transfer case is making a noise like it is trying to engage/disengage 4 wheel. I would think that this would narrow the possibilities of what could be wrong....

[Jethro_Canada]

Time to take it into the shop, get a pro to look at it.

[rich60630]

i had the same problem with my 98 if the 4x4 is not disengaging i was lucky it was just the fuse in the fuse center under the hood not in the car! The fuse was blown and after i replaced it it worked fine. Also if u have a whinning noise when not in 4x4 and than it goes away when the 4x4 is engaged that is the automatic locking hub that is half engaged and half disengaged! This happened too me comming back from Branson, MO last summer i drove it 600 miles like that and by the time i got it too chevrlet it cost 1750 dollars to fix!! if its half engaged u r just chewing the hub to bits

[rlith]

This is a typical symptom of a bad encoder motor on the transfer case. But before changing that, check the vac switch on the transfer case, they tend to go bad because the check ball inside gets sticky... But I'm leaning towards the encoder motor.

[Jimmy95]

When I found out how much GM wants for a encoder motor $750 canadian I just about freaked. So I called a Transmission place and explained that I did not have cash to fix it just now and asked if there was a way to manually put it in 2 wheel.. He said all that I had to do was unhook the module on the passenger kick plate. I did and now the light still says that I am in 4 wheel, but I am in 2 wheel for sure. But now my airbag light is on. But I am in 2 wheel drive. Does this change the diagnosis at all?

[rlith]

not really.... Grab an encoder motor from a wrecking yard... The best thing to do is always fix it right the 1st time... If you try to find ways around doing it and do it half assed, you'll just frustrate yourself... Also if you don't want to check wrecking yards, check your local auto parts stores for it, and barring all else, get teh part number from your local dealer and run that number at www.gmpartsdirect.com you will probably end up with it cheaper from there

[JoshBarber]

can you tell me what the fuse part number was, and what it costs?