Doug_Scott

If it is a 4 wheel drive, with the front end jacked up and on stands, turn the wheel by hand to full left and try rotating the tire by hand, repeat for full right turn. If you can feel the wheel trying to straight out, and then return back to full turn it is likely a front axle outer cv joint starting to seize. Check cv boots for any cuts or grease leaking out. Seizing ball joints is an easy check as Riverbanks suggests, and is something you should check. Not uncommon for seized ball joints to break with no warning. If you have see a vehicle on the side of the road with one wheel folded up inside the fender, that is a broken ball joint.

Check both fuse panels, one in engine bay, one on left side of dash. If you changed out the rear lights, put original back in and see if backup lights work again. If they are still out, take it to dealer and just say backup lights don't work. See if warranty covers it.

Never fix yourself what is free at the dealer. You make one simple mistake and short something out, you will be paying for the denied warranty claim.

Cheaper to simply put a piece of wood on the gas pedal. It will do the same thing until your muscle memory learns it. You could then remove it and think the vehicle is a real dog now.

See if the dealer has a new vehicle on the lot that you can take for a test drive and see if that noise is in that truck as well. My first thought would be that with so many gears being produced inside the case via planetary gear sets it may be simple something that needs to be "worn in". Make sure it is documented fully by the dealer so that there is prior notice of it having a gear noise in the transmission in the notes for your trucks VIN. If the truck has a manual shift switch, try manually changing gears while the noise is happening, have to think a 10 speed will not be in 10th gear at that speed. If it changes/goes away as soon as it shifts either up or down (in other words it only whines in 4th gear) the dealer will have something to go on. In every gear there is a unique pattern to what clutch pack/band is applied that routes power through the planetary gear sets. If just one of those gear sets has some minor alignment issue it will make a noise. There is a shop on Youtube called Precision Transmission that has videos of him taking transmissions apart, watch a few of those to get an idea of how the power is passed through the various gears. Isn't this the same transmission Ford is using in there trucks? Maybe take one of those for a test drive to see if they also make the same noise. It would not surprise me if this is simply a meshing issue that needs to be run in.

This will be a bit more positive message. Personally, I would rather have the shop tell me they can't duplicate the issue than start throwing "best guess" fixes at it. Having been a mechanic, I would tell the customer that I was not able to reproduce the issue if the issue did not happen. I also would explain that without experiencing the issue it would simply be a guess to offer a diagnosis. I would suggest they take their vehicle and pay attention to what they did to make it appear. Once they find the way to reproduce the issue, verify a few times that those steps cause the issue to return then bring the vehicle back. To me, the only thing worse than being wrong was getting caught when wrong.

I doubt an oil separation can would even require CARB approval. It does not impact engine running or emissions. CARB approvals very likely aren't free, and perhaps no one is willing to pay for something that will simply take too long to recover the expense.

When I added steering wheel controls to my 2010 Sierra that also had cruise, I changed the complete steering wheel over to the leather wrapped wheel with full steering wheel controls. It was a plug and play operation, just replaced the complete steering wheel. No other changes, including wiring changes, were required. Don't recall exactly, but the steering wheel was around $100 from one of the large GM online parts website and took about 2 weeks to arrive by me in Canada.

If you are thinking it is more likely not anything related to the aftermarket stuff, go to your installer and have them remove all the connections they made to install the various items. If the error is still there, then go back to the dealer(assuming it is under warranty) and have them call in their service people. Don't know about the states, but in Canada dealers do not do entertainment repairs themselves. They call in a service company that they have been using for decades likely and have them repair it. Back in 97 when I factory ordered my 98 Pontiac Grand Prix GTP, it arrived without the 6 CD changer in the trunk. It did have the main harness wire there, cut off. The dealer called in their repair company to run the harness into the trunk and bolt the cd changer back in place. I had to wait an additional 4 days because the stereo guy was busy. I have no idea why it required the stereo guy, this was simple parts install. Point is dealers don't do anything they can farm out and make an easy 10 to 25% on it. Back in 81 I had to repair 2 Plymouth Sapporo's that our outside stereo guy did the install wrong on them. Father/daughter bought identical cars, except colour and had expensive aftermarket stereos put in. Took me 4 hours on the first car to find that the installer tapped into what he thought was the power feed for the dash lights. Sapporos as I came to discover, didn't put the rheostat on the power side of the bulbs, they put it on the ground side. You had to see the effect of a variable ground on a power wire to a stereo. Service manager told me to bill 4 hours on the second car even though I fixed it outside without even sitting in it.

The vibration only just started didn't it? U-joints cannot be checked with the driveshaft installed. If one trunnion is starting to seize it will not be detectable with shaft in place, it must be removed to check for any tightness. You should also check to see if the lockup convertor is working correctly. Easiest way to check the convertor is to get the convertor to either unlock, or select a gear with the shifter that does not have the lockup as part of the gear. I don't know if the 6 speed unlocks the convertor when you brake, but you can try to just touch the brake pedal with your left foot enough to turn the brake lights on. Leave your right foot on the gas while doing this and see if the RPMs increase. If it does, try to get the vibration to occur. You will need to keep the brake lights on to keep the convertor from locking up. If that does not work for unlocking the convertor, perhaps there is a fuse for it.

Is this the 4spd or 6spd? Put shifter in 3 and see if it is the same. U-joint vibration is usually lower in vehicle speed, and does not matter what gear it is in. You may want to remove the shaft and move the u-joint through its range of motion, feeling for smoothness through out the entire range. You can take off the two caps with the shaft off of the differential end of the shaft and look for lots of lubrication. You should not see any shadow lines that look like the bearings have been stationary.

Have you noticed you have to select the recirculation button every time you start the engine? I don't have auto HVAC in my truck, and it resets itself sometime between the time I turn the engine off all the way to the time I restart the truck. At that point I have to reselect the recirculation button again. You may want to check the floors for any water being held by the carpet. I had a 98 Pontiac GTP that when it rained the drivers side floor would be so wet that the WeatherTech floor mat would be floating in the water. No matter how dry I got it, it would be humid in the summer, and would collect frost on the inside of all the windows overnight due water on the floor. Leak ended up being from the seam of joint between the door plug and the roof(the seam you can see on the roof at both sides, a couple of inches in on each side of the roof. Dealer didn't have any idea of how to repair it, I didn't really care, told them to just seal the seam up with RTV or some 2 part epoxy. Car was leased.

This may be too obvious, but, is your original problem still there?

If you are going to be running 10 feet of cable for the load you may want to rethink the gauge of the wire. You could also use a second run of the 10 gauge wire in parallel.

20 hours can mean you are without a vehicle for a minimum of 3 days, likely taking 4 days. I can remember bitching about having to pull the intake on the B/RB Chrylser engines to change lifters. They were a dry intake manifold, didn't have to pull distributor or even drain rad. Intake gasket was turkey pan with no paper gaskets. Can't imagine having spend over a day just to get it apart. Its likely just as easy to pull the engine and do the work on the bench.

Submerged in oil will prevent corrosion. It does cause issues with wire flexibility though, but since it never moves it does create issues. Surprised it acted up for them. Usually sporatic issues only show up on the drive home from the dealership. Pretty sure the update was just about the most on-topic post. Thanks for updating.

The 4L60E does that too. Have a friend with a 2004 Sierra with 5.3 and the 4L60E. If he leaves it in Drive when towing his trailer and comes to a hill on a road with an 80km/h speed limit it will begin slowing down, leaving the convertor locked up, until it gets to about 55-60km/h and it will unlock the convertor and downshift two gears into second. Rpm will jump to over 4500rpm, and he just goes along with it and holds the gas pedal just short of WOT. Next hill he remembers to put it into 3 before hitting the hill. His truck has 3.23 gears. The 4L60E in my 2010 Sierra with the 4.8 used to do that with no tailor but with the cruise on, at the same 80km/h would do the 2 gear downshift about 2/3 the way up the hill. I had 3.23 gears as well. After the change to 4.10 gears, no more issues with cruise on hills. Not much change in mileage either.

I found it by clicking a link inside a link. I wonder if they are actually talking about the fluid when they say "substrate". It is still a completely incorrect use of the word, after all, fluid has less letters, with ATF having only the 3 letters. The dip in temperature that is instantaneous (for ex. 102°F change to 48°F in one step) would indicate a connection issue. The connection issue could be in the connector at the temp sensor, or one of the connections back in the harness. I would expect to see corrosion in that connection if it is loose. You could get the transmission hot, then put the front end of the truck on stands, and take your scan tool under the truck with you or have someone watch the temp its displaying while you go under the truck and jiggle the wire at its connection points looking for a temp change of more than a degree at a time. No idea how much a sensor is, but, if it is one of those $10 ones, just change it. Time it takes to check it is longer than $10 worth of time. Check connections first though. Back when I became a mechanic you had to be 18, and have at least a grade 10 education. We have had licensed mechanics at least since the end of WW2 in Ontario Canada. Growing up it was common to hear parents say that if little Jimmy doesn't smarten up he will end up being a mechanic, plumber or tv repairman. Now you have to have some 2 year college course in order to technically get a license. And even after making the education change, no mechanic would ever use GMs definition of substrate. My first guess was the stuff you put under paving stones in your driveway. Then again, I only left high school with my grade 10. Having fun was much entertaining than school. Besides, I wanted to be a mechanic.

Did you see this already.. https://www.dtcdecode.com/GMC/P0711 Also found a line in your original pdf link that says "TCM internal temperature (substrate)" To me that means in their minds, substrate is internal temperature. Don't know why they would toss a different word there when they already had a nice descriptive phrase that was easy to understand. I could understand it if this document was hand written, having to manually write out TCM internal temperature many times would make it worthwhile using a shorter word. But this is a pdf file. Just put the repetitive long phrases that are commonly used into a paste buffer, and use the couple of key strokes to paste the phrase in. Substrate is not even close to being useful in describing anything to do with transmission temperatures.

I would think that if the "computer" is seeing zero pressure in the A/C system there must be a sensor telling the computer there is zero psi. If the sensor is a simple 2 wire sensor, unplug it and see what happens. If it still runs, short the two pins together while it is still unplugged. If it is a 3 wire plug, you will need to trick the connection to not report zero psi. With that being said, it does not really make any sense to run the fan with zero psi in the system. Is the clutch engaging on the compressor as well? If it is, pull the plug on the sensor on the accumulator, that should stop the compressor from engaging, in turn making the fan stop. The fan will still work if the engine overheats/gets hot. Try checking for a fuse or relay that is marked Fan High Speed. Don't know if they have their own relay or fuse, but it only costs time to check and see.

No, the o rings are there to prevent the line from leaking outward. Those lines are also transmission cooler lines.

Back in the day, used to use free-wheeling hubs on the rear wheels to tow the race car to the track. You would need to use 4 hubs. Isn't the single speed transfer case used in the Auto 4 wheel drive vehicles? Do the single speed transfer cases have some form or oil pump in them? I just can't imagine why it really makes a difference when flat towing. You could also undo the driveshaft from both diffs and tie them up into the chassis. By removing from the differential you won't have to deal with the shafts moving. Both differentials will self lubricate when towed.

I always give the repair shop first crack at fixing any issue after a repair. Its the best way to find out if the shop is good or not.

I think it is too late for the obvious, but, back away from the wallet. It is a very rare day that throwing money at something will fix it. Antifreeze can enter the crankcase only a couple of ways. The first and second most common ways are in the cylinder head area. The head could be cracked, or could be porous. Check out this thread . Your truck is a little bit early to have the bad heads, but, its still something that is usually the first thing checked. A blown head gasket could also let coolant into the crankcase. What you need to do is this, loosen the radiator cap and let the truck idle in the driveway. Get it hot, but do not drive it. Once it is hot, tighten the cap up. Let truck idle 5 more minutes, then shut it off. Let the truck sit for a couple of days, the longer the better. After a few days, put a clean drain pan under the oil pan. Loosen the drain plug slowly, and watch to see what comes out of the drain plug first. If you see fluid the same colour as your anti-freeze then you now know for sure it is something to do with heads. By running the engine with the rad cap loose, it will prevent the coolant from getting into the crankcase. After tightening the cap and running it for 5 minutes or so, it will build some pressure up. Shutting it off will also push the pressure up a bit, and if there is a pressure leak in the cylinder heads, it will push coolant into the crankcase. Since oil is lighter than coolant, and then engine is not running, the coolant will gather in the bottom of the pan. Over time some oil will give up the coolant, and it will sink to the bottom of the pan. Anything that leaks in without engine running will go straight to the bottom. You could also just let the truck sit a few days without running it at all, and loosen the drain plug on the stone cold engine and watch what comes out first. You should be able to slowly loosen the plug and use the plugs slow down the first of the liquid to drain out. The oil is cold and will not flow very fast making it easier to keep the plug at the last thread. Water will be easy to see coming out, but, don't blink or turn your head away. Let us know what comes out when you try this.

I think he is saying the shifter moves, but it just does not actually shift. I am saying that because he says the engine just revs when he shifts into any gear. It has to be something that knows it is raining. Not trying to be funny, I mean whatever it is, is being impacted by the water. When you say if you wait a while it will work, do you mean if you just leave the truck where it is, and not running, it will drive some time later? Does it have to stop raining? What happens if you leave it idling for 30-45 minutes?