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Posted
5 hours ago, newdude said:

 

 

If the harness has never been replaced at all before, you need both pieces because the original design harness is a one piece unit.  Once its been updated to the new two piece style, if in the event of future temp sensor failure you can then just buy the valve body half of the harness.  

 

The valve body its a 50/50 if it has to be removed to change the harness correctly.  Depends on if there is a connector in a certain spot on the harness or not.  

I understand much better now. I really appreciate your time to describe it to me.

Posted
22 hours ago, Sean_McNulty said:

Mine came out to $1057. The guy at service desk took off the diagnostic fee so that took $110 off. I can tell you that my truck hasn’t ever shifted as good as it did in the hour drive from the dealership. Feels like a whole new truck. 

Thats exciting, thanks for posting the results. Really hoping these random rough shifts stop as well.

  • 1 month later...
Posted

Thank you for the warranty information. I have a 2017 Yukon Denali 6.2 8 speed. I have the exact same issue. Same two fault codes (P0700 & P0711). I get the hard shifts occasionally. And at highway speeds of more than 65 mph it sounds as though I'm in 4 wheel drive even though it reads 2 wheel drive.

 

I also have the engine Ticking noise that started this past winter and never went away. Bugs the crazy out of me. Sounds like lifters but not sure. Any help with this noise would be greatly appreciated. 

Posted
18 hours ago, CMate said:

Thank you for the warranty information. I have a 2017 Yukon Denali 6.2 8 speed. I have the exact same issue. Same two fault codes (P0700 & P0711). I get the hard shifts occasionally. And at highway speeds of more than 65 mph it sounds as though I'm in 4 wheel drive even though it reads 2 wheel drive.

 

I also have the engine Ticking noise that started this past winter and never went away. Bugs the crazy out of me. Sounds like lifters but not sure. Any help with this noise would be greatly appreciated. 

I just started getting the same 2 fault codes in my 2017 Silverado 6.2 8 speed. Wonder if mine will be covered under this tsb? Even though it says it's only for 2016s I took delivery of my truck August 1st of 2016.

Posted

Had this done yesterday at dealer for my 2015.  Covered under extended warranty, which will expire in about 500 miles.

 

Seems to shift smoother than ever.   Probably also due to the clean fluid. The sensor was wonky for the last say 15k miles, but not bad enough to throw codes.

 

I had already drained and filled 8 speed on my own twice in the last 5000 miles (13 qts new fluid) then this - so the fluid is all fresh at this point.

 

It only took 100k miles to get this thing shifting nicely 😆!

  • Like 1
  • 3 months later...
Posted

I have a 2016 Yukon Denali throwing PO700 and PO711. Very rough shifting and stuttering. Nowhere on the special extended coverage release does it say 8 speed only. https://static.nhtsa.gov/odi/tsbs/2020/MC-10178408-9999.pdf 

I've got the 6.2L V8 with a 6 speed transmission. My dealer is backed up for 6 weeks because they can't get transmission fluid. From the release the fluid required is Mobil 1 Synthetic LV HP Automatic Transmission Fluid 19417577  which I can have delivered to the dealer by Amazon in 3 days. The dealer says GM must source the fluid themselves and will not pay for the repair unless it comes from GM which sounds nuts to me. Anyone else have this problem? Also, can anyone point me to a TSB or other release stating the extended warranty is for the 8 speed only? Thanks

Posted

I guess I got screwed on this. Last winter, i was getting the 700 and 711 codes but they went away and came back several times. Once the weather warmed up, the codes never came back. Fast forward to last month. Lifter started ticking so I took it in to the dealer. Asked them to check the temp and the A8 shudder. They fixed the ticking (bent push rod, 4 new lifters) but since no code was stored, no dice on the temp sensor. They then said the extended warranty would not cover the trans shutter, wanted $600 plus to flush. Ended up doing the sensor and fluid change myself. A little sloppy but not that bad. Sensor was only $65 or so. 

  • Like 1
Posted
On 9/18/2020 at 9:42 PM, 16sierra said:

FYI for anyone reading this thread, this only applies to the 6.2L + 8 speed. No luck on the 5.3L + 8 speed.

Is the fix the same for the 5.3L + 8 speed? Transmission Wiring Harness?

Posted
On 6/16/2021 at 4:30 PM, Differcult said:

I understand much better now. I really appreciate your time to describe it to me.

So you did ultimately get your 5.3L+8 speed fixed? Did yours have the 10-way or 4-way connector?

  • 2 weeks later...
Posted (edited)

I have a 2016 GMC Sierra SLT and went through the transmission shudder back in 2019 and the dealer did the flush at no cost to me now I had to go back this week for a P0711 TFT sensor / harness failure. I presented the special coverage # N192291660 to the service tech and he noted that this did not apply to the 5.3. When I asked him what is the difference we are talking about the 8 speed auto transmission the same as in the 6.2 to which he agreed. I called the division number for GMC 1-866-996-9463 and was told that there was a certain range of 6.2's that had this problem which made no sense to me what does it matter what size engine 5.3 or 6.2 and is beside the point. One thing for all GMC owners to keep in mind is that the average temp should be around 180 degrees plus or minus according to the load on the engine. I would suggest that if you are observing 135 degrees like I was should have brought this up before my warranty expired 6 months earlier this year, my bad. Anyhow I registered my complaint with the dealer and the GMC contact line.

Edited by Wayne Edward
correction
  • Like 1
  • 4 weeks later...
Posted

Thank you guys for this thread! Bought a 16’ Sierra 1500 Black Widow with 6.2L and 1 week later threw 0700 and 0711. Been driving it for a month until I started to do research and landed on this thread . At first GMC dealer in Houston said no special coverage for my truck with 109k (bought with 104k), but called GM and they said I did have coverage . Getting it repaired Tuesday for free! Car fax shows this truck had transmission work done around 45k miles but at this point just waiting on lifter failure. 

  • 4 months later...
Posted

Had the trans issue now,  almost out of warranty and the dealer covered it.  2015 Silverado LTZ 6.2L 8 speed. Looks like I got lucky :). Temps seem a bit drastic, but I think that is why it was failing.  Been shifting badly for years. Tried to find the parts they installed, but not what I've seen in this thread.

 

TransRepair.thumb.jpg.92511f3c98c9ca3b52462067588682d6.jpg

  • 2 months later...

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