99 Tahoe stuck in 4lo. Help

[josh99tahoe]

I need some help guys, my Tahoe stuck in four low with the four low indicator flashing. I have replaced the TCCM, The encoder motor, and the selector switch. I cleared the codes once all these were replaced, I was throwing a C0323 code now nothing. I don't know what else to try except for throwing money at it, any help is appreciated

 

[SunlitComet]

make sure the encoder and t-case were on the same sync before install and make sure the t-case is not jammed physically and that the power feeds to the tccm system are all intact.

 

[josh99tahoe]

make sure the encoder and t-case were on the same sync before install and make sure the t-case is not jammed physically and that the power feeds to the tccm system are all intact.

the replaced encoder motor now is siezed up i beleive. i can hear it trying to work. it doesn't move at all though.

the adapter piece from TC was lined up with the encoder motor. how do i do a functions check on the transfer case it self?

I know you can manually shift it into neutral by using a 1/2 wrench on the adapter piece.

 

[SunlitComet]

Then run wire tests for the encoder circuits including power and grounds to make sure hey are not broken or damaged and test the motor while it is removed from the t-case for proper operation.

 

[josh99tahoe]

Then run wire tests for the encoder circuits including power and grounds to make sure hey are not broken or damaged and test the motor while it is removed from the t-case for proper operation.

removed motor from transfer case...

1. manually shifted TC back into 2hi so i can drive it.

2. switch selector is still blinking in 4lo

3. encoder motor (just took off junk truck and was working last week) buzzes and will not switch positions.

So i'm probly going to get another encoder motor and see if that does anything, unless any one else has any ideas.


Side note. Ive hear alot about the vacuum switch going bad frequently, replacement is 17 bucks. i will probly swith this out also.

 

[SunlitComet]

If shift motor is buzzing and not moving it sounds like the intense electric brake is not releasing. Either it is jammed or the power to release the brake is not coming from the tccm for some reason. Make sure brake release power is getting to the motor before replacing the motor again.

---------- Post added at 11:26 AM ---------- Previous post was at 11:24 AM ----------

BTW what vacuum switch are you talking about? The hoe uses no such thing in the 4wd.

 

[josh99tahoe]

in the process of checking wire from tccm to TC and wire from fuse box to TC. will keep the forum updated