Great Site Folks ,searching issues brought me here


Wife driving our Yukon the other night and the gauges quit(except Vmeter) , door locks cycling on their own ,tranny shifting really hard ,rear power hatch will not open (power sunroof works) tach and oil p. slightly pulse just off zero intermittenly . WIL NOT COMMUNICATE WITH SCANNER

what I have tried
Tested terminating resistor above rear tire (120 ohms ) as per spec .
front to back physically wiggled all connections and wire harness seeing if gauges would react .I used to be a tech (left for a new career in 1990)
Any help would be appreciated



this came off another forum

I fought this problem for months, door locks, stabilitrack, traction control, gauges going dead or acting erratic, brakes dragging and applying themsevles, and transmission shifting HARD. My 07 Tahoe stayed at the dealership for 3 1/2 months before they figured it out. Here is a list of items they replaced that did NOT help.

Body control module
powertrain control module
Transmission control module
they checked all the connnectors between the Hi and Low speed LAN circuits.
They went as far as telling me that my DVD player which came in the truck was causing the problem... I called bull**** on it. Told them I wanted a factory rep involved and hired a lawyer. The rep got some high paid techs involved and they ended up replacing a terminating resistor in the wiring harness (by the spare tire) and the negative battery cable. It has not done it now for about 6 months. I don't want to go through this , more than not trouble shoot with parts

 

Some have found a shorted connection at the wiring harness were it connects under the fuse block under the hood.

Others have had issues with corrosion within the battery cables.

It's not going to be easy to find.

 

Welcome to Corrupted Area Network, the gold standard in reliability for a new century!

 

thanks for the tips , yes i am pulling my hair out , but every little insight like that helps !!

 

sounds like a bad ground to me

 

yes i have been exploring that . Ground on battery to chassis has .01 voltage drop , but the rest of the ground areas around the chassis I don't know.
thanks for your reply

 

removed the fuse block , no issues found , no green , no arcing marks

 

07's had tons of problems with the underhood power center right off the bat we had a few acting up as they were being unloaded off the transport.

Without being there to check stuff we had a bunch of yukons and yukon xl's in the 07-08 year models that would go crazy just like yours and the exact symptoms and it was the underhood UBEC. Put in a new one and they worked like new.

 

do they have a circuit board inside them ?

I really appreciate the insight !!

I'm really starting to loose it

 

what would u check test if you were here?