07 Yukon slt 4wd nerwork problems, service stsbilitrak, service 4wd lights intermittently on and off

[ClutchSA]

07 Yukon slt 4wd nerwork problems, service stsbilitrak, service 4wd lights intermittently on and off. Dealership baffled . Started months ,worse now

Stabilitrak light came and went randomly. When on i would get rough 1-2 shifting. It lasted a few minutes and went off, shifted ok. Problem woukd stay away for weeks. Then it would come back and the service 4wd message would appear also or by itself. If i stopped a couple of times car would not restart till 15 minutes later, jumps would not help. Other random symptoms like gauges goind dead, ac compressor would go off , door locks went crazy all randomly after driving about 20 minutes or after hard restart.
I ve done a lot of fiddling like checking grounds , checking can bus resistance test ok. Replaced bcm but now only service 4wd message permanently on. Sometimes stabilitrak light comes back on and ABS light also. Sporadically.

 

[Fless]

Save the original parts -- they are at times more valuable and reliable than any aftermarket parts. Was the BCM programmed for your VIN?

What codes are present? Active, history, and pending...

What tests has the dealer performed?

When you say it wouldn't start until after 15 minutes passed, is that a no-crank, or crank-no-start?

Has a comprehensive voltage drop test been done for both the negative and positive circuits to the engine, and for the body ground? The main cables can rot from the inside out without showing any issues on the outside. A voltage drop test will verify circuit integrity and current capacity.

Also, pull the underhood fusebox and look for corrosion underneath.

I'm sure other members will have comments.

 

[rdezs]

Neutral safety switch, AKA transmission range sensor.... Can cause all those issues. Bolted onto the driver side of the transmission, and it's one part you want to stick with genuine GM and avoid the aftermarket. Pick yourself up a heat gun at harbor freight.... You need to heat up the big plug from the harness that plugs into it in order to get it out usually, without damaging the plug. Not aware of an easy way to test it.... You'll note from the number of wires that go into the plug, several systems monitor it for gear position. Takes 5 or 10 minutes to replace, held on by two 10 mm bolts. If I remember correctly, the nut that holds the shift lever to the end of the shaft is a 15 mm. Based on age alone, it's something you want to change for preventative maintenance.