Hi gang, hoping for some knowledge and experience from the collective with the following issue/s that decided to render me car-less for the foreseeable future.

I wish I had something better to talk about, but hey, I'm now engaging with the collective.

I took my C63 for a quick drive the other night to go to the beach and relax after a high-impact two week swing on site. In the preceding two weeks before that, I had a family member move my car around for me from the front yard to the garage and vice-versa. Nothing to high octane about that. Anyway, I noticed that the transmission was playing up as I was driving back from the beach, it was only minor in nature at the time.
Now the real story starts on Sunday, I had to go out and run an errand, which thankfully was only about 10kms away from home. Started the car, everything sounded normal, pulled out of the drive way and was on my way. As I was driving and coming to roundabouts, traffic lights, stop signs etc, the gearbox wasn't changing gears like normal (i.e. still in 5th at 20km/h, slowing down), and when taking off, the car would rev it's head off before changing gears. Just as I got to where my errand was, the driveway into the compound is on a very slight gradient. From a stand still and in D, I couldn't get it to play the game, so used my paddle shifters to get into 1st gear. That seemed to stifle the beast a bit. I thought I might just drive it in M mode with the paddle shifter, if it's being a pain in the butt to drive home. Oh yes, it gets better now.
As I took off from completing the errand, the gear changes were getting more spasmodic and erratic, not pulling off at all, gears jumping around erratically like a 5 year old who has been given the keys to a lolly factory. I kid you not. At one stage, I pulled the car over , pulled open the bonnet to see if anything was knackered, nope. Thought I'd letter the car coll down a bit (and let traffic clear out) before limping home.
Anyway, that didn't work. 500m from where I pulled over, the engine warning light came on. I pulled up in a driveway for an Animal Rescue Compound (no where was there, so I was luckily able to park up off a main road.
Now I've got a scan tool, so thought I'd plug it in and see what "good" news I have. Here are the codes (7 off) for your viewing pleasure:

1) 0894 - The Gear Is Implausible Or The Transmission Is Slipping;
2) 0731 - Gear 1 Is Implausible Or The Transmission Is Slipping;
3) 0731 - The Gear Is Implausible Or The Transmission Is Slipping (Gear {0});
4) 2761 - The Pressure Regulating Valve Of The Torque Converter Lockup Clutch Has An Electrical Fault Or An Open Circuit; <-- This one has me concerned
5) 0729 - The Gear Is Implausible Or The Transmission Is Slipping (Gear {0});
6) 076F - The Gear Is Implausible Or The Transmission Is Slipping (Gear {0}); &
7) 0735 - The Gear Is Implausible Or The Transmission Is Slipping (Gear {0}).

Hoping to see if anyone else has these come out and if it's an easy (?) fix, or if it's a terminal issue.

For everyone's FYI - car has 156k on the clock, I've had it since 2018 and got it with 69k on it. No maintenance has been completed on the transmission whilst I have had it. I service the car every 15k, no mods (K & N Air Filter Replacements only).

 

156k on the clock and you say no transmission maintenance has been done by you. Do you know if the previous owner(s) did a maintenance in the past?
I'm not a transmission specialist, but I can imagine with 156k under the belt and perhaps no transmission maintenance, the clutch packs could be worn out.
I assume you have the newer MCT transmission.

 

with those codes unless it's out of fluid thats a transmission replacement / rebuild. she done.