Duelin

I don't think he shorted a comm line. He mentioned that the release button works when he plugs the wiper motor back in. I would imagine that the release button won't work if the wipers are on (just guessing) they probably don't want the wipers running if the glass is in the up position . So when he unplugs the wiper motor the BCM can't complete the communication and denies control of the release button. Just my antiquated way of thinking. If he had access to Alldata or Mitchell on Demand they should have the theory of operation and how it works.

I think that is controlled by the body control module. And when you disconnected the wipers it interrupts the communication that controls the system. You will have to get a wiring diagram and see what you are dealing with.

You say that you have a new battery. Just because its new doesn't mean that it is good. I had problems with mine. After three batteries I finally got a good one. So from now on any time I buy a battery I will be checking to make sure they are good and up to specs.

Any time you move a tire from one position to another that position has to be relearned. If you don't do the relearn the bcm thinks the tire you removed from that position is still there. Not to be confuse with installing a new TPMS sensor that needs to be programmed. The device the that monitors the tpms is the Body Control Module.

Let me throw one more comment in here. If all the parts you have installed are aftermarket parts and not OEM there is a good possibility that you have created more problems than you started with. A large amount of aftermarket parts aren't even worth the boxes they are shipped in. And don't even work out of those boxes. Anyway Good Luck

parallel hybrid trucks

One of the best way to find out is go to a body shop that does frame work. They will have a data base of all the frame measurements. Myself I kind of doubt it. The 1999 - 2006 sierra is built on the GMT800/880 platform. The 2000-2006 Tahoe is built on the GMT820 platform. Good Luck

I would start by installing a mechanical oil pressure gauge. That eliminate a lot of questions. Like is the new sending unit working correctly "all the parts you buy today is risky", is the wiring ok, is the gauge reading right? If it still reads the same then I would try a heavier grade oil. If the pressure comes up with the heavier grade of oil then its like Mr. Dirt said, time to look at the bearings and check the wear on the crank. May the luck of the Irish be with you . Good Luck

I have gone back and read your post. I didn't see where that you have verified that you have an RPM reference from the crank sensor while cranking. Do you? If so disregard.

I would be looking at the blend doors. And If you have a bi-directional scanner you can reset the positions of the blend doors to their home position. Its not uncommon for them to get out of calibration. Also what can happen is the heater blend door has a piece of foam that helps seal the door when closed. And every once in a while that foam will come loose and fall down and jam up between the door. And then instead of sealing the door shut it jams the door open and won't let close all the way. Now you will get constant heat moving thru there. Good Luck

I am not sure what you meant by all my lights are good. But one thing that can cause problems with these models are aftermarket LED lights. Don't know if you might have installed some LED lights or not . Good Luck

Yes!!! The mobile techs in my area are charging $185 for Gm vehicles and as much as $300 for Chrysler vehicles.

I would also check for intake manifold gasket leak. Which is not an unusual problem with those engines. Good Luck

This might help. https://www.gm-trucks.com/forums/applications/core/interface/file/attachment.php?id=126832

Here is an article that may be useful for your project in case you haven't seen it already. http://www.k0bg.com/wiring.html Here is one sentence that is in the article. It is imperative that the ELD not be bypassed when wiring amateur radio equipment, so typical wiring recommendations found in Owner's Manuals should not be followed!