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Doug_Scott last won the day on January 17 2018

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About Doug_Scott

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  • Birthday 04/11/1959

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  1. 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.
  2. 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.
  3. 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.
  4. 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.
  5. No, the o rings are there to prevent the line from leaking outward. Those lines are also transmission cooler lines.
  6. 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.
  7. 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.
  8. 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.
  9. 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?
  10. Trying to apply logic to how things are done in the business world is a waste of time. Why do they do something to save $5 per vehicle when they could just as easily raised the price by $10 and earn $5 more profit per vehicle? If a car company sells a quarter million vehicles per year, how hard is it to not slip a $4 rise in dealer cost on every vehicle and earn a cool million dollars more that year? I am by no means even remotely intelligent in business, I must be missing something, it just seems so easy to me. What am I not understanding? A long time ago I was told that a business can never recover the profit lost due to theft. I fell asleep while the guy explained it.
  11. Is GM allowing anyone to get a new bin file(or whatever they call it) for your ECM? For example, when I changed the rear axle gear set 10 years ago GM would not send the dealer a new updated ECM file to correct the issues created when going to 4:10 from 3:23. Whats the price for one of those boxes?
  12. I think you will find that the part numbers are not created with regards to the number it is replacing. When the technician calls the tech line to get an updated firmware it will include the newest version of each module.
  13. How are you testing the starter motor? Watch the dome light while trying to start the truck, it should only dim slightly. If it is going out completely, then you have a bad battery or battery cable. Take a good look at both battery cables where the lug is crimped on. If the insulation is bulging there pull on the cable to stress the crimp connector to see if white powder comes out.
  14. I think you will find it wasn't dropped because the media made it into a news item, that was about the time that CAFE came into being, and that 40 gallons of fuel was double the weight of the standard fuel load. It was an easy way lose some weight. That was back when Volkswagen used to advertise the Beetle had 13 pounds of paint on it, and their favorite slogan was "Volkswagens will definitely float, but they won't float indefinitely". I know, off topic, it was just one of those things that pops into your head when you think back in time.
  15. Something like 7.3 pounds a gallon, that would be a real gallon, not the little ones you have in the states.
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