2000 Tahoe ABS Activating and Service 4wd

[76zimmer]

You need to have the codes pulled from the tccm,something most generic scan tools cannot do,to find out what the problem is. Chances are its the encoder position sensor on the fritz.
Code will be c0327 if that's the case

Agree with this!
My 99 2500 has the push button and the encoder motor was corroded real bad where it bolts to the t/c
That corrosion kept the motor from functioning properly and eventually it wouldn't dis engage 4wd
I had. Shop diagnose it as there was only the "service 4wd" light on
That motor is easy to change and if badly corroded just replace it
Be sure to match the encoder motor position to the position of the t/c input

 

[Chevy305]

Ok so since I need to go to a dealer to get my tcase codes read, I went to a Chevy dealer to read the "service 4wd" codes. The first dealer said "sorry my guys are on lunch." The second dealer said we need to charge a minimum of 1 hr labor to read codes at $130 per hour I told them to put it where the sun doesn't shine. I went to a third dealer and they hooked up and told me what it was at no charge. I say it's because the third dealer was located over the border in New Hampshire, LIVE FREE OF DIE!!!!

Ok so short story even shorter, the code my tcase was throwing was "B2725" which means the dash 4wd switch. I just ordered a new one on Amazon for $35 shipped so it should be a cheap fix

Also on an unrelated note, the check engine light came on. The codes it showed were P0230 which means "Fuel pump relay control circuit low voltage" and P0463 which means "Fuel level sensor circuit high voltage."
I'm thinking that since my gas gauge is the typical older GM, in that it only works most of the time, I'm thinking it messed up enough to set off the SES light. I know the sensor needs to be replaced for the level indicating problems but is this the fuel pump failing? If it is I'll be sure to get right on the sender replacement.

 

[jeff in co]

I'm sitting at -10 degrees this morning and came out to the truck (04 Yukon XL) with a "Service 4wd" light displayed. Coming home from work last night, I left it in 4WD and parked it so I don't know if it being so cold has anything to do with it. I'll probably check the dealer later today but wanted to know....

Did the new dash switch fix your problem??

 

[Chevy305]

Ya the new dash swutch fixed my problem. But the only way to know is to have the dealer read the codes.

 

[jeff in co]

Cool, thanks. I'll swing by later today and find out the code.....