4Hi but not 4Lo
 

Greetings all. Not a transmission man, so I need some more wisdom. My '04 with the 3 button on the dash will not go into 4Lo. I can get 4Hi, but when I try the low gear the light on the button blinks for a minute and it goes back to high gear. Any ideas?

Check out the "4x4 no worky" thread in the DIY section. Odds are it is the encoder (shift) motor, but there is a TCCM diagnostic procedure in there which should narrow it down for you.

seen that before. doesn't have anything for my particular situation though. I'm gonna see if I have any codes stored and go from there.

That's what I meant...tracking down the codes (post #5 in that thread). Have never had to do the DTC procedure, but seems like it ought to be fairly easy.

did you put it in Neutral when hitting 4LO button?

always in neutral when I hit the button. anyone got a pic of where I hook up to get the codes?

It would help to know what vehicle you're talking about. Don't have a pic handy, but it should be under the drivers side dash. Either near the top of the parking brake or under the steering column. You probably will have to get your head near seat level to see it.

The year of your vehicle also matters, as it could be OBDI or OBDII.

Found a pic. Not necessarily for a Blazer, but the location is in the general area.

Edit: Oops missed where you did list your year.
https://blazerforum.com/forum/data:i...UczHiik23p/9k=

You just jumper one of the pins on the OBD plug to ground. I forget which pin, it's on this site somewhere. The 4wd buttons will flash a sequence, and display the stored codes. You said yours is an '04, so it is definitely OBD II, and this will work.

No codes are stored. This is gonna get ugly...

mine has trouble getting out of 4lo most of the time, i think my encoder is just old and dieing... hardly use 4lo tho