You are welcome. Sorry, but the other forum is wrong about pulling the 4WD fuse. Unfortunately there is lots of BS out there and no real way to tell. But in reality the only way to clear codes in the 4-button TCCM is with a scanner and very few commercial scanners will communicate with the TCCM through the OBD2 connector. (The three-button non-auto TCCM clears/reads a few simple codes through the 4WD control). But if your friend has a high end scanner, it is certainly worth a try to see if it is capable. FYI when you successfully clear codes, the 4-button TCCM will give a fairly loud click.

Remember that driving with the encoder motor and/or TCCM unhooked will certainly set a code and you will need to reinstall the encoder motor at your friend's shop or a code will immediately be set. If he is a good friend, push for him to bring his scanner to you!! Still at some point you will want to make sure the transfer case will physically move through the gear selections.

Let us know how things turn out. Please keep in mind that a bad encoder motor can short out and ruin the TCCM too. That is the case that I had with mine - but it was blowing the 20A ATC fuse under the hood. Most common problem with TCCMs is corrosion at the big red wire at the TCCM connector. Second most common problem is position sensor in encoder motor goes bad.

Best wishes,

 

next day next step...I took of the t-case motor and took it out of neutral...donīt know if 2hi or 4hi....and drove to my Buddys workshop. Took the t-case back onto neutral, put the encoder motor back onto the t-case and made a scan. He uses the Bosch interface and this one wonīt go into the tccm or elsewhere, but the next problem was shown. My speedometer is on 200km/h and stays there. Is there another encoder or something else at the plugs of the encoder motor?? I think I have to look for another interface that works with my Blazer

 

Not sure what you mean with your question about another encoder at the plugs of the encoder motor. Communication with the 4-button TCCM is done through the OBD2 connector under the left side of the dash. The 4-button TCCM is on the same in-vehicle "network" as the PowertrainControlModule and BodyControlModule - all are accessed through the same scanner connection (they are just at different addresses on the network).

Interfaces that connect to the 4WD TCCM are very uncommon. Tech 2 is the ony one I know that connects in a nice interface without sending/receiving hexadecimal. If anyone else knows of any other options, now would be the time.......

If you want to do the hexadecimal thing to communicate with your TCCM, here is the OBD2 interface that I successfully used:

https://www.scantool.net/scan-tools/obdlink-sx/

I used Scan XL Pro software on a Windows Netbook in a "custom terminal" to accomplish the communication. Unfortunately this software is $150.

This OBDLinkSX scan tool happens to come with complimentary software called OBD2WIZ, and it also is supposed to have an OBD2 terminal built in. See KEY features here. They call it an OBD Console:

https://www.scantool.net/obdwiz/

I have never installed this software but I do have it. If you are seriously interested in buying the OBDLinkSX and using this complimentary software for hexadecimal communication with your TCCM, I will try it out to make sure it works for successful communication first. Based on my negative experience with terminals on Android phone through bluetooth device, to me there is question if you can type hexadecimal directly into the OBD2Wiz terminal the way I have done it. Let me know how you want to proceed.

 

Yesterday we made the next steps....Mr.Postman deliverd my OBD cable and we looked at the TCCM. It seams that everything is ok.Than we decided to take a look at the t-case motor. Took it out and checked it....it looks like that this is the problem īcause the motor is dead. Now I have to order a new one but thatīs not so easy to get a cheap one here in Germany.

 

Iīve orderd a new one at rockauto.com ;-) It costs 50% than here in Germany and with the express shipping Iīll get it next monday ;-)

 

Dorman 600901 or Cardone 48105 from Rock Auto. They will ship Internationally. So did you do the hexadecimal thing for communication?

 

Today Rockauto deliverd the new Transfer case motor and the Blazer is running....but only with the original "damaged" TCCM. I think the second one that I bought is damaged and killed my old t-case motor īcause it gave no signal to the new one but clicked inside. I changed it to the old original one and it was on 4Hi. After a little bit "playing" and talking good to gm the old one went into 2Hi but with the 4wd service lamp on.After two new starts the 4wd light was off and didnīt come back until now. Iīthink Iīll buy a new TCCM with the same number like my original one and hope that my 4WD will work "normal" THX for your help Les

 

You are welcome. Glad you have made progress. Let us know how the new TCCM works when you get it!

Best regards,

Les