I have a 2001 s-10 blazer. The last time it was put in 4hi and 4lo it worked fine.Now my service 4wd light is on and neither of my pushbuttons are lit up or working. Any advice on what to check first, besides fuses of course.

 

Encoder motor.
Have a look at that - specifically the connectors going to it. One of them could be corroded. If not, you may have a bad encoder motor. They're famous for going on the 01 Blazers. If you're lucky you can get away with just replacing a connector (like I did).

 

Before throwing an encoder motor in it you should disconnect both battery terminals and touch them together. Sometimes the Transfer case control module trips. Doing that usually resets them. After trying that if it still doesn't work you will probably wanna look at the encoder motor.

 

Check the connections at the TCCM (behind the passenger side kick panel). Clean them regardless of whether they look bad or not. Then do the battery disconnect.

If that doesn't do it, then take it in and have the TCCM scanned. A dealer Tech2 or equivalent full feature scan tool must be used to access the TCCM and read the codes. The fact that your service 4wd light is on means that the TCCM has stored a code that will tell you what it is having a problem with.

While replacing the encoder motor does tend to fix a good majority of these types of problems, your problem should still be diagnosed first before throwing parts at it.

For further information, please run a search on NV236 and you should find quite a few threads on the diagnosis and repair of your transfer case.

 

Yup, Theres a ton of things those Tech 2's can do. If you know someone at a dealer get him to throw a Tech2 on it and see if you can command the Service 4wd message off. If it turns off, replace the TCCM. I work at a GM dealer and those TCCM's are fairly common to go. They are actually notorious for corroding and causing a bad connection and making them not work. I'd do just like Kyle said and clean them regardless.

 

I missed that this was in the Off Roading section...

*Moving to 2nd Gen Tech*

 

YES people like me who are right^^^^^ the TCCM goes all the time i work at a GM dealer also and these things go bad all the time like my boys ubove me said dissconnect the connector under the passenger side kick pannel it will be at the bottom of the right front fender on the inside of the truck dissconnect it for 10 seconds with the key off. Then plug it back in see if it fix's your problem, you can also dissconnect the battery but keep the battery connected while dissconnecting the TCCM, this will trip the TCCM its like a manual reset button for your 4x4

 

First off, Thanks for everyones help! I'm pretty good at replacing parts just horrible at troubleshooting! I cleaned the tccm connectors, nothing happened. I diconnected the battery cables and touched them together. This got the service 4wd light off but the pushbuttons are still not lit or working.Any more tips for the technically challenged?

 

Once again thanks for all the help! Can someone point me to the right location of the encoder motor?

 

Take a test light and connect it to a good ground, take the switch out and press the test light against the back terminals of each button while your pressing it. like have the car on, engine off press 4Hi and have the test light on the back of the terminal for the 4HI button. Make sure your getting contact with the terminals. If the test light does Not light up, it means you need a new shift control switch. If it does light up, you're probably looking at an encoder motor.
Sorry it took so long to answer,