07 suburban service 4wd

[Storage Fam]

Hey guys new here got a question I bought this 07 suburban 3 weeks ago. The other day it was raining pretty bad my wife was driving and she switched it into auto becuase of the pooling of water on the highways. Ran fine no issues at all. Next day she gets in starts it up and "service 4wd" comes up on the dash. I came home from work at this time it was still in auto I switched it to 4hi and went around the block I know it went it it was a pain to turn the truck. I then came home parked it tried to switch to 2wd nothing happened light stayed on 4hi but it was clearly in 2wd but message was still illuminated. After stressing it I googled alot I just keep finding info for 2nd gen suburbans not many for 3rd generation. But I pulled the fuse for the transfer case motor and I took the ground wire off the frame cleaned it all up put it back on. Turned truck on showed it was in 2wd everything was good. Today I ran down to the store on my way back service 4wd came back on while it was still in 2wd no noise no DTC codes nothing so im stumped im afraid to drive it because of the issue i don't want to trash a truck I just paid 12k for. From what I read it could be the selector motor on the transfer case or the acutator on the front axle forget what its called excatally just wondering if someone can point me in any direction before I start throwing parts at it. I don't want to have to drop the drive shaft to change the selector motor if i don't have to and it doesn't seem like its a terriable issue due to the fact there no DTC but I dont want to attempt to change into 4wd and have it get stuck in 4wd I rather it be stuck in 2wd. Thank you guys inadvance. 

[Jsdirt]

You need to have it scanned for B-codes in the transfer case. I'm betting it has a bad dial switch on the dash - mine failed back when the truck was brand new. You may be on your 2nd or 3rd unit by now. Very common. 

 

Don't replace anything until you find out which B-code has been stored. I believe a B2725 is the switch one, but don't quote me on that. You could have other issues, so winging parts can get expensive.

 

Luckily IF it is the switch, it's only around $20 online, and very easy to install with just plastic prying devices.

Edited July 13, 2020 by Jsdirt