Engine Check Light Codes p0700/p0711
 

My 17 with only 27k miles check engine light just popped on. Also got an OnStar notification about an issue with my Engine & Transmission.

Got the light checked and 2 codes popped up

-p0700
-p0711

Ended up taking it to the local dealer. They had to replace the Transmission harness and fluid. Originally they quoted me at around $700. But since my was purchased as a Certified pre-owned, there was no charge.

Posting as information for anyone experiencing a similar problem.

Just got this code in my 2017 SS with the 8-speed auto. Car is out of warranty but even if it was under warranty, I would still do this repair myself.

Have the updated harness, a new filter, and fluid on order.

Seems to be an easy fix.