I know that this has been covered, but there is a slight difference I live in the UK and don't really have a Chevy dealer even close to me, well saying that there is a Chevy dealer but there not American cars there hideous Daewoo’s http://www.chevrolet.co.uk/matiz/matiz-index.html.
I was out in the blazer yesterday and I decided to shift into 2 HI manually after I had to pull away quite quickly I got some wheel spin and thought I better put it back into auto 4wd then my service 4wd light came on, any ideas?

The only thing different I have done recently is move some heavy items well washing machine etc you know moving house sort of stuff....


Please help....
Thanks
Graham

 

So what is different besides the fact that you do not have a dealer close?? What questions do you have and what threads have you read?

So far the only thing we know is you have a 2nd gen (no year given) and that the service 4wd light is on (no mention of Auto4wd option...).

 

It's a 2000 Blazer LT

I did say it had the Auto Option, I have read a few threads saying going to a garage with a scanner (for error codes) but obviously I can't do that

 

Oh also all the lights disappear on the switch including the auto option

and just found this quote from dosser

Ran across a shop manual and I was reading over the Encoder Diag. It says When DTC Sets the Service indicator will be on, all shifting disabled, the shift lights will be disabled, and the next time system is powered on the TCCM will power up as if the 4HI was the mode present when powered down. I don't know if this helps anyone. Just thought I'd throw it out there!

This explains all my symptons but I haven't a clue what it means

 

It just means that there has been a problem that the TCCM has identified and disabled shifting to prevent further problems. You can pull the TCCM fuse to reset the system and it may work for a time.

I would start by removing the passenger side kick panel cover and having a look at the connections on the TCCM. It is possible that the connections are corroded and the proper power is not reaching the encoder motor on the transfer case.

This is typically caused by a faulty/failing Encoder motor. The motors will become weak as they age and not fully transition into the different gears. The problems typically start with engagement to 4LO. There is a position sensor in the encoder motor that also does not help the situation as they are on the inaccurate side which can further add to the problem.

You should check the other stuff out first as the encoder motor is quite expensive.