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Discussion Starter #1
Hi, I just found and joined the forum. I have a question regarding the Transfer Case Module. I assume mine is bad as I have replaced the 4x4 switch and still have the same problem. the indicator on the switch stays on auto. My question is, If I buy a new Module from GM direct , is it plug and play ? I understand used ones have to be flashed at the dealer and I really don't want a used one anyways . Thanks in advance, bob
 

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2004 gmc envoy_slt
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Your best bet is to get one at a salvage yard (preferably one from a model year close to yours) or a used one on Ebay. Used TCCMs do not need programming as long as they came out of a similar vehicle. New ones do have to be programmed.
All that being said, are you definitely sure it is a TCCM? Do you the Service 4x4 light on the dash? Do you hear two distinct motor sounds when switching between 2HI and 4HI (or A4WD)?
 

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thank you for your reply , I got one from an 05 , looks identical, wires identical but it says online its not compatible with an 08 . I have not tried it yet as I didnt want to screw something up, So, no not 100% sure thats what it is, just going by what i have seen online and I replaced the switch, yes the 4x4 light with wrench on the dash is on . I have never tried to switch it driving up the road , I dont have it plated yet , I would drive it up and down the road no problem to listen for motor sounds , but switching the switch sitting there with it running, I dont hear anything when I switch the switch, nothing changes with the original one in there
 

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There apparently was a change in part number from 2006 +. The GM P/N for a 2008 TCCM is 24233623 and for 2002-2005 is 12590220. Don't know what the differences are.
 

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yes, thank you , so I have the 05 one, guess it will not work. may put it in for the heck of it .I will have to call around some yards but if they want 100 bucks for it and have no returns on electrical , I may as well get a new one and have it programmed . I wonder , since its showing AUTO on the switch now if it actually performs that way ?
 

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ordered on on ebay 30 bucks says it works and same number as mine 24233673 so will see when it arrives . suppose its best to disconnect and cross + - battery cables to clean everything before I install this one and try it , when it arrives ?
 

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If you disconnect the battery, you should clean the throttle body (front and back) because the PCM will reset to factory settings.
 

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Thank you very much for the tip, I will do that. I'm currently going over it , checking things out , give her an oil spray and got a little spot of rust to fix . but for southern Ontario and being an 08 the body and underside are surprisingly excellent . She has about 165 Miles on her and doesn't make a sound , everything works except that 4x4 switch its an LT, leather sunroof , butt heat , and the dealer offer my friend 500 bucks on the new equinox she bought , so i got it for 500, thats about 5 bucks US lolllllllll
 

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Hi, I just found and joined the forum. I have a question regarding the Transfer Case Module. I assume mine is bad as I have replaced the 4x4 switch and still have the same problem. the indicator on the switch stays on auto. My question is, If I buy a new Module from GM direct , is it plug and play ? I understand used ones have to be flashed at the dealer and I really don't want a used one anyways . Thanks in advance, bob
drive it slow in 4hi and you will feel it working...DRIVE SLOW in drive and slowly turn the steering wheel, you will feel it bind on the dry pavement and feel the steering be a little stiffer.
offroadtb.com/diagnosing-the-4wd-system/
 

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I am going to say (educated guess) your issue will likely be the encoder ring (position sensor) inside the transfer case shift motor.
 

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Discussion Starter #14
drive it slow in 4hi and you will feel it working...DRIVE SLOW in drive and slowly turn the steering wheel, you will feel it bind on the dry pavement and feel the steering be a little stiffer.
offroadtb.com/diagnosing-the-4wd-system/
 

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Discussion Starter #15
Thanks very much for the reply and help ! Waiting on the used module to arrive and will give it a try as soon as it does !! Thanks again, Bob
 

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Discussion Starter #17
I just read your post on this encoder ring (position sensor) INSIDE the transfer case shift motor ?? Major job ??? I have to research this now .
 

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Discussion Starter #18
looking at what I think you are taking about TJBaker , shift motor , rather small looks like motor on the end ? flat plug ? see some on ebay 99 buck new and did not look real hard yet
 

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The part I posted about is a sensor inside the transfer case shift motor. The overwhelming majority of people replace the entire shift motor, more commonly called the encoder motor, instead of replacing the sensor inside of it. This is maybe a wise choice but clearly a more expensive one as the motor is a good deal more money than the roughly $55 dollar sensor. But before I would advise anyone to go this cheaper route I would caution them to thoroughly test all of the encoder motor circuits to confirm that this is indeed the trouble source.

Replacing the sensor instead of the entire encoder/motor adds maybe 15 minutes to the job. In a nutshell the plastic insulator plate is held in place by 4 plastic lock tabs, the sensor is the round disk seen in the attached image. Carefully remove the old sensor, disconnect the harness then reverse the process to install the new sensor. Care must be taken to be certain not to damage the seals on the insulator plate.
IMG_20191207_123146.jpg
 

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Discussion Starter #20
Thank you for the info and picture, it helps a lot. I would not know much on how to test each circuit as you advised, so maybe my best route to go would be an entire new motor for 140 . shame we had an 05 envoy in the yard 2 days ago before i knew about this motor, lol, so now its in the bin and gone to Detroit for shreading ((
 
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