My service 4WD light is on and all the lights are lit up on the buttons (auto 4wd, 2hi, 4low, and red neutral light any suggestions on where to start? Should I take it somewhere to plug it in for diagnostic chk. as in Autozone or somewhere like that and will that give a code?

 

You have to use a scan tool that is capable of communicating with the serial bus connected devices such as the TCCM is. Your typical over the counter scanners will not be able to do this.

You can start with the usual checking of connections at the TCCM, switch, and encoder motor.

 

Man ,KYLE you are such a good Administrator, I no this must get old to you on this subject. How many times do people ask about this SAME subject. You have GOOD PATIENCE. Thank you for your Timeless Support and Knowledge. You Help keep this a GREAT Forum. T.J.

 

Came down to being TCCM. Now the question is what years will work? It is an 2001 Blazer with 4 button unit. Any help is appreciated, thanks.

 

Any 4-button equiped s-series truck should be a suitable donor.

 

Before you buy a TCCM, check the voltages on the supply harness, and also check the ground(s) for shorts.

I'm about to do this for the controller motor on the T/C in a day or 2, and get some pics up. The TCCM is easier to do, being in the passenger compartment.

 

any update on this?
i hit 4x4 hi and the lights on the buttons lit up and service 4x4 came on the dash...
it wont go into 4x4.