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There is never any "Dumb Questions"
This harness is for an A8 , i bought it for my 2015 . I searched high and low to make sure I bought the correct harness but .... i would always check to make sure your car is listed as one that it will fit
Dave
Thank you 🙏 I've read most of your comments on here and you've been super helpful and now even helped me I appreciate you!
My bad, I meant to say drain plug. In my case I guess removing the pan will be a messy affair.
I see the fill plug is difficult to get to and the fluid must be pumped in.
To confirm, the Harness part number is: GM 24298757 ?
Before u drop the pan you need a pump like the one below to empty it and to fill it . HARBOR Freight has it and it's cheap
It's actually very easy to use to use . Stick the hose in the fill hole and the other end in your empty container, and pump . You do the reverse to fill . When I did mine it left very little fluid in the pan
Are you aware of how to check to see if you have the correct fluid level ?
As far as part number , I can only tell you that it was the correct number for my 2015 LT1 A8 ..... and verifying that was difficult. Maybe call a dealer and verify
I did some more research on the part number, and it has changed from GM 24298757 to GM 24046895 for a 15 C7 A8. Rockauto has a generic version, but I would stay with the OEM harness
Not sure of how to check the correct fluid level. What ever happened to the good old dip stick?
Not sure of how to check the correct fluid level. What ever happened to the good old dip stick?
They have not had a dipstick for a long time ..you do know where the trans is located right ....lol lol how in the world would you expect them to install a dipstick lol lol
Google it , it's easy but ... you do have to warm the fluid up
So another question for you. Did you have to clear the codes or did the codes clear on their own?
I don't have a C7 (I actually have a C6 GS) but I also have a 2017 Camaro SS that has the exact same 8-speed auto as the C7's. I just changed my harness because of the P0700 and P0711 codes. Was not difficult. Pump out fluid, drop pan, clean pan and magnets, remove old filter, replace harness, install new filter then pan, pump in new fluid and perform fluid level check proceedure.
Just wondering if the codes will reset themselves now that the issue if corrected or if I need to manually clear the codes?
After X amount of starts if the TCM/ECM does not see the fault the CEL will go out
But you can just go to any auto parts store or buy a cheap scanner and have the code cleared
Dave
I have a Banks gauge as well as an OBDII dongle that can clear the codes if necessary.
But the code went away on it's own.
After I did the harness replacement and then fluid procedure, I drove the car on a couple of errands. Parked car overnight. Then the next day, I started the car up and the code and CEL disappeared. Good to know it is now fixed.
I'd say that if you have any vehicle that has the 8-speed auto trans and will be doing a filter and fluid change, you should purchase the harness and change it at the same time. Couldn't be easier to fix.
First I want to thank the OP. I love threads that actually fix something and are documented well enough to help others in the future. I try to do that when I discover a good fix. I had to do this repair on my 2015 vette recently. Totally fixed the problem. Not a hard repair. I wanted to contribute to the thread and pay it forward. Also note that my code reader is a cheap Innova 3100 code scanner that would not clear the code. Since the P0711 is a permanent code you need to have a good scanner or software that can clear permanent codes, or just wait for it to clear on its own after several key/warm up cycles. My code cleared by itself about 5 cycles.
As GM usually does there are updated part numbers for the harness and the filter. I have noted the changes below in case someone is needing to order this stuff for their fix. As noted above my car is a 2015 C7 and the parts below fixed me up, but I bet they are common for other vehicles also. But double check and do your homework.
New part number for A8 filter that fit my 2015 New part number for the A8 harness with temp sensor. Has the same colored wires as noted in the OP’s original post.
First I want to thank the OP. I love threads that actually fix something and are documented well enough to help others in the future. I try to do that when I discover a good fix. I had to do this repair on my 2015 vette recently. Totally fixed the problem. Not a hard repair. I wanted to contribute to the thread and pay it forward. Also note that my code reader is a cheap Innova 3100 code scanner that would clear the code. Since the P0711 is a permanent code you need to have a good scanner or software that can clear permanent codes, or just wait for it to clear on its own after several key/warm up cycles. My code cleared by itself about 5 cycles.
As GM usually does there are updated part numbers for the harness and the filter. I have noted the changes below in case someone is needing to order this stuff for their fix. As noted above my car is a 2015 C7 and the parts below fixed me up, but I bet they are common for other vehicles also. But double check and do your homework New part number for A8 filter that fit my 2015 New part number for the A8 harness with temp sensor. Has the same colored wires as noted in the OP’s original post.
Thanks for posting the new part numbers and continuing to pay it forward...... This is what these forums are all about.... Back when I changed my harness confirming the right part number was the hardest part of the job ....
It is so refreshing to have people on this site that actually know what they are talking about, no WAGS (wild *** guesses).
I read too many of them, WAGS, and they are not helpful.
Thank you Dave, it people like you and DiagC5 and a few others (can't remember them all offhand, but you know who you are) that keep this site viable and relevant.
Thanks for posting the new part numbers and continuing to pay it forward...... This is what these forums are all about.... Back when I changed my harness confirming the right part number was the hardest part of the job ....
Dave
Ha! That’s what made me think to add to the thread since your original post was done a while back. Trying to keep it updated for others. I have had the same part number issue before. And not just on GM products.
One other note for others in the future. I ended up only needing about 6.5 qts of fluid. I added 7 qts when I did the job and then drove the car a few times to clear the code and checked my level today intending to top it off. with the trans at 125F and idling in park, I pulled the level check plug in the front corner of the pan that has the “standpipe” in it and surprise fluid drained out for about 5 seconds. I guess about 1/4 of a qt drained out. I know Dave you had to add 7.5 qts so not sure why the difference. Maybe my car was tilted a little on the 2 post lift? Dunno but I’m gonna leave it.
It is so refreshing to have people on this site that actually know what they are talking about, no WAGS (wild *** guesses).
I read too many of them, WAGS, and they are not helpful.
Thank you Dave, it people like you and DiagC5 and a few others (can't remember them all offhand, but you know who you are) that keep this site viable and relevant.
Yep , its a short in the harness that can be intermittent, i would get a temperature reading sometimes but it was way lower than expected like 125 degrees F running down the highway at 70 MPH and sometimes my guage would not move at all , which is usually accompanied by a check engine light
I was clearing the code at least once a year for a few years when it got cold out , then the code started to show up more frequently until it got to the point where i was not sure if my Check engine light was coming on because of other reasons or it was just the temp sensor so I finally replaced the harness
As far as urgent a repair? Mine did not affect transmission performance at all so it was more of a matter that i could not stand the fact that i would pop a CEL at any time and not be sure if it was something serious or just the sensor
Dave
Hello Dave, I know this is an old forum posting but I've got A 16 Z convertible, A8 same color as yours and it's got the P0 700 and P0711 codes and the check engine light, but mine did not seem to affect how it drove. My first question is you cleared the code and drove it around or and it didn't bother anything. I saw you said you cleared it like once a year but I just wanted to make sure I was reading that correctly and not reading and posting about something else. And then the wiring harness upper and lower. I suppose I have to hold the harness in my hand to understand exactly what you mean. I'm assuming it comes apart by a connector of some sort and the lower portion has the temperature sensor on it. Just gathering data before I attempt or bite the bullet pay to have it done my only concern is the mess as I don't have a lift trying to get side to let me buy quick jack but it's a tough sell when it is always something going on with my car lol great posting thanks for taking the time is is very helpful for us gear heads with a budget or a an account wife
thanks again
Ken
With the A8 it is ok to drive it because the fault does not put the car into limp mode. The ribbon cable inside the transmission pan is bad or has a broken connection for the temperature sensor and that is the reason for the P0700 and P0711 code. My dealership changed mine and put new fluid in it for under $500. That is drain install new cable and refill the fluid, which is not too bad considering I had none of the tools to do it and did not want to do it Hope this helps
I drove my 2017 Camaro for over 2 years before I replaced the harness in the transmission. I would get a trans code every 3 or 4 months which I would just clear. Transmission never shifted any different or put the car in limp mode. But over time the code started showing up more and more frequently.
I dropped the pan myself and changed out the harness. It is quite easy and easy to do.
Reinstalled the pan and a new filter and then followed the proper procedure for filling and level of the fluid.
Hope this helps