I have a 01 Jimmy slt and yesterday after I put it in 4hi (for the first time in a long time) the lights on the switch died and the "service 4x4" light came on. After the vehicle was off for a while I started it up and the light was off and I put in back in 2wd and everything was fine, but now today the light cam back on when I haven't even touched the switch. Any ideas? I know engines and have done a couple of tranny's but I mostly do bodywork now. I don't have a clue about 4x4 though.

 

You have the NV236 4-button Auto4wd transfer case which means that in order to pull the codes, you will have to get a compatible scan tool to read them. The scan tool will need to be able to communicate with the TCCM which is a serial bus connected device in this case.

 

Where is the connector? I have an older OTC scanner (I think the last update was around 2000) that has multiple connectors. Or do you need a newer one that just goes to the OBD2 socket? I only have a cheap newer OBD2 reader that only does the basics, so I don't think that will cut it

 

You plug into the regular OBD2 DLC under the driver side dash. Your scan tool MUST be capable of accessing the other serial bus connected devices to be able to read the TCCM.

 

I will try my old OTC scanner and see if the chip is new enough. Thanks