Just picked up my first blazer, its a 2001 UK spec 4x4 four door with a manual transmission. On the way home the "Service 4wd" light on the dash lit for a short while. What does this mean and what needs doing generally. I am pretty comfortable with 4wd vehicles, happy to change gearbox oils etc. Whats likely to need doing?

 

i have had this happen 2x to me, both times was the first time it snowed for the year.
first time was 5 years ago.. was going to take it in to the shop the next day i tried it and no issues.
second time was just this year.. same thing, go to put it in 4x4 service light pops up and it sticks in 2wd.
i went outside a few hours later, pushed and held the 4x4 hi button it struggled but popped in.
now it works perfect again and ive used it a few times since.
dont know what to make of this other than thinking maybe i got some frost in the air line or somewhere and it wouldnt engage the 4x4 but then after it going in once its back to normal.
try holding the button for like 10 seconds... may work may not. worst thing that happens is you loose 10 seconds of your life.

 

It seems to shift into 4wd OK, I was thinking it was probably down to lack of use tbh. Is there anything that can be greased/oiled to smooth things out at all?

 

The 'service 4wd' being illuminated means that the TCCM has stored codes relating to a fault it has detected. A full feature scan tool is required to pull these codes. Without the codes, you are flying blind in terms of repairs. You can run through the simple things of checking connections at the switch, TCCM, and encoder motor for corrosion and that they are securely fastened. You can also check the resistance values from the switch (search "NV236+resistance" with an author of "swartlkk"). Besides that, get the codes read.

 

Thanks, I'll run through the basics and then consider taking it to get any codes read. The main importer for these is only about 20 miles away from me and they will be able to read the codes, possibly about the only ones in the UK that can!