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I purchased my TCCM from GM Parts Direct. It cost about $200 Shipped.

Here is how you replace it.

First take off the panel under the steering wheel and the pannel that is below that



This is what you will see from under neath the blue clip goes into the TCCM there are 3 different plugs that clip in there. It is right behind the metal plate that you will see when you take off the pannel, It is all the way to the drivers side.


These are the 3 plugs after you take them out of the TCCM They unclip pretty easily but require a little contortion to get your hand up there to them. I am sure you could just take more stuff off but this wasnt too bad.



This is how they go in the TCCM. Note, you cannot put them in before you pop the new TCCM into its bracket. This is just so you can see the order of the plugs because you won't be able to read the label on the TCCM when you put it into place.



Clip the TCCM into its bracket, and install the plugs. The small black plug goes all the way to the passenger side, I labeled them in the drawing.



Put the dash back together, go to the dealer and get it programed.


any questions just ask here, don't PM me
 

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Great info - thank you so much for posting the process.

Any trouble driving the vehicle after swapping the TCCM out?

If you can - let us know what they get you for ($$) to do the re-programming of the TCCM at the dealership.

Thanks again - exactly what I needed to get this thing replaced on our TB.

Dave
 

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2004 chevy trailblazer_ls
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TCCM needs to be reprogrammed? I had an issue with mine a few months back. I was getting the Service 4WD light and the switch didnt have any indicator lights on. I swapped out the TCCM with one from ebay, No Problems since... never went to dealer...
 

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Mario,

Someone, somewhere had mentioned that you do not need to get the newer, redesigned TCCM "reprogrammed" - whatever they did with the redesign eliminated the need to reprogram...not sure, but it sounds like it worked for you.

It will be interesting to see what they tell Vartz04 when he goes to the dealership...thanks for the input!

Dave
 

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TCCM needs to be reprogrammed? I had an issue with mine a few months back. I was getting the Service 4WD light and the switch didnt have any indicator lights on. I swapped out the TCCM with one from ebay, No Problems since... never went to dealer...
So did I, installed a -04 TCCM on my -02 TB...no problem. :thumbsup:

//Pelle
 

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Discussion Starter #6
well I took mine to the dealer, they said they cannot communicate with the replacement. So something else is up I guess.
 

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Hey Jeff -

That sucks. Question: Did you ever get a trouble code reading for the TCCM to diagnose it? My mechanic originally ran the diagnostic and came up with a trouble code - it was # CO-550, which came up as something to do with the TCCM / ECU. Sort of vague though...

Just wondering if you were going off of a specific diagnostic trouble code, or off the hunch that it was your TCCM based on your research of the problem?

Thanks -

Dave
 

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I know this Thread is over a month old, however i still think we need to follow up with the question asked previously, "Does another used 02 Trailblazer Module which is in current working condition a fix to install in an 02 Trailblazer with a bad TCCM?"


The Reason i ask is because i've heard that the 02 model TCCM is not Programmable... So does that mean that after the circuit is lost, it goes into sleep mode, Forever? Please share light on this since i find it difficult to understand that after a dead battery it would not work.
 

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Here is what I did

I put a working TCCM from an 03 Trailblazer EXT into our 02 Trailblazer, works just fine, we did not reprogram the 03 unit. The old one out of the 02 was dead (no lights on 4WD switch/service 4wd light, dead TCCM code) I would think another working 02 TCCM would work in TB with a bad TCCM.

I know this Thread is over a month old, however i still think we need to follow up with the question asked previously, "Does another used 02 Trailblazer Module which is in current working condition a fix to install in an 02 Trailblazer with a bad TCCM?"


The Reason i ask is because i've heard that the 02 model TCCM is not Programmable... So does that mean that after the circuit is lost, it goes into sleep mode, Forever? Please share light on this since i find it difficult to understand that after a dead battery it would not work.
 

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2002 tccm issue

was wondering if the 03 and 02 tccm are interchangeable on the trailblazer. is the tccm located in the same place on the 03 as the 02. my 02 is on the drivers side and looking at another website it shows a picture of it on the passenger side http://kylestubbins.com/node/11 , they look different in the pictures. any help is appreciated
 

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They're interchangable, and located above the closeout panel near the driver's left knee. That other site you looked at was discussing a Canadian 2003 S10 full-size Blazer. Not a GMT360 trailvoy kind of vehicle.
 

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trying to save a buck and a trip to the dealer

thanks for your reply to my question, i am trying to decide which avenue to go with. i found one in a junkyard in an 03 for $75. i hear the dealer charges $275 for the part alone and that it still has to be programmed. is this true? or can i just install a new one and avoid the dealer? or can i just put in a used one and be done without having to program?
thanks for your help, i would love to avoid the stealer i mean dealer.
 

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tccm

I have a similar problem. Every now and then my 02's battery would be dead. I could not for the life of me figure out why. It would be fine for a week, a month, a day. Even fully charged it would sometimes be dead 2 hrs after the lalst time I ran it. After each dead battery the lights on the 4wd selector were out and I could not change out of 2wd. After driving for a random amount of time it would come back on and be fine til the battery died again. I broke down and took her to the dealer. They said the ignition switch was draining the battery. They changed it out..275. They checked the tccm and it is dead. The truck is going back in next week when the part gets here. GM tccm in Whitehorse Yukon?.....675$ plus labour. Guess I have to do my part to keep them out of chapter 11. After hitting this site. Im feeling a bit ill knowing I could have fixed it myself. Id tell them to go pound sand, but I already agreed to have them ship one here and have them install. Next time something is wrong Ill check TRAILVOY first. Great site people. Keep it up puleese!
 

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...or can i just put in a used one and be done without having to program?...
Sorry for the late reply. The TCCM should have the VIN programmed into it by a dealer's tech tool so it knows what gear ratio is in the vehicle. It also needs to know if it's being put into an AWD or 4WD vehicle - same TCCM is in both of them, but only the 4WD TCCM needs to control the front axle actuator. AWD vehicle's front axles are engaged all the time mechanically, and are missing the splined disconnect and actuator installed in the part-time 4WD trucks.

Many members have bought used TCCMs and plugged them in and they work fine, because statistically (I think) most of the vehicles with control problems are 4WD and even if the gear ratio is off the functional effect is minor.

... took her to the dealer. They said the ignition switch was draining the battery. They changed it out..275.
Down here, you can buy a switch for US$30 and change it in a half hour. But you found that out already, I expect.
They checked the tccm and it is dead. The truck is going back in next week when the part gets here. GM tccm in Whitehorse Yukon?.....675$ plus labour.
$200 at parts4chevys.com. $75 on Ebay. 15 minutes to install. Then you pay the dealer 1/2-1 hour to program.
Guess I have to do my part to keep them out of chapter 11.
The mechanics have to eat, too. And by paying the local dealer, you keep them from begging in the streets. At least the money isn't going offshore or to Mexico. :ugh:
After hitting this site. Im feeling a bit ill knowing I could have fixed it myself. Id tell them to go pound sand, but I already agreed to have them ship one here and have them install. Next time something is wrong Ill check TRAILVOY first. Great site people. Keep it up puleese!
Thanks. We try. :D
 

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The mechanics have to eat, too. And by paying the local dealer, you keep them from be

Hehe, true enough. Maybe I can help wake someone up who is on the "job bank" program and get them out of the lunchroom.
 

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Thank you for your replies, they are very informative and greatly appreciated. due to my frugalness, i think that i will be trying the salvage yard route and gamble with the $75 that he wants for the part. when i ever get around to it i will let you know of my outcome, since the snow has left us for the season now. i did however take the old one out to get the numbers off of it and when i reinstalled the tccm, the trailblazer did not want to start. it sounded like the timing was wayyyyy off, it finally started and worked its bugs out though, i guess some of the computer info was out of whack.
 

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ok so which hARNESS ties in from the the 4wd switch to the tccm?

Working on an olds bravada 4wd swap.....I have essentially all the mechanical parts tccm 4wd switch harness etc.....

I know the tccm between the bravada and tb are the same p/n....

So thaT means that the wiring/pinout are similar if not the same,,,,,,

So can I splice into the bravada harness. and run it to the 4wd switch?
 

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The TCCM has more features than the Bravada harness can support. Specifically, the Bravada doesn't have the front axle actuator, and its TC connector is 5-pin (no brake solenoid) versus the TB's 7-pin. But many of the connectors are the same, such as the ones on the switch and TCCM.
 

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The directions on this post are great on how to install the TCCM. However, the photos have been removed. Is there anyway you can repost them or I can retrieve?

Thanks!
 

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Only if he gets them rehosted. I don't trust free picture hosting, and recommend people attach pics to their threads to make sure trailvoy hosts them here for longevity.

Anyway, here's a compnine.com exploded view of the location. The TCCM is item #2. It's really quite trivial once you know about where it is on the dash panel above the driver's left knee.

 
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