I have a 2011 GTC with around 22k miles and an engine service light came on and noticeable loss of power. Drive home and ran VCDS and have so many codes I don’t know where to start.

I’ve read many of the codes can be attributed to either bad battery/batteries or possibly a bad ground. Any help or suggestions would be appreciated.

VCDS scan is attached

 

Start all over again , except charge up the LHS battery and keep a charger ( ideally a trickle ) on it while scanning .
Doors open , weak battery = voltage drop and its Christmas time for the codes .

Publish the 1 or 2 that actually caused the CEL .

 

I will leave the trickle charger on overnight (Drivers side LHS, battery) then clear codes and run Scan again see how things look.

Also will do some reading on how to change plugs and coils. The GTC is nothing like my 50 year old trucks ignition system.

If I’m able to run the scan tomorrow I’ll post results. Thanks

 

I fully charged the battery and left the trickle charger on while clearing codes. Took two tries but all codes except satellite radio are cleared.

Started the car and all sounded well.
Drove 25 miles. and list the following.
0-10 miles kept under 40 MPH with slow starts.
Noticed slight stumble at mile 7
Temp hit 200 at around mile 8.
Mile 10 - 16 highway accelerate to 80 MPH
Noticed stumble during acceleration and loss of power.
Mile 16-25 Back roads again down to 40 MPH
Noticed more stumbling and misfires
At stop light clear misfire. Loss of power at acceleration

Attached is the scan.

Pretty clear something is going on with at least Cyl 11. so I will plan to replace coils and plugs. Any suggestions on who to buy plugs, coils and intake gasket from?

What are your thoughts on the other trouble codes?

Thanks

 

I would wait to see what @Johnny Hotspur GT and the others say.

If this wasn't a Bentley I'd say the misfire is a symptom of a dodgy connection to one of the ECU's

C

 

Indeed sir!
With intermittent power to the ECU I'd expect random misfires. However, Number 11 occurred in the original log as well, so I'd have to agree!

C

 

CatmanV2 are you suggesting that since the issue reoccurred at cyl 11 it’s likely a coil/plug at least at that location?

my experience with coils, as limited as it is, once one goes others are soon to follow and the work to get to them, in my opinion I am better off replacing all.

mid the issue is connection to the ECU how is that corrected?

 

I wouldn't take my opinion as gospel.

*Without* the ECU intermittent power fault I would absolutely go coils / plugs. And given the amount of work, and, as you say, they often fail at close intervals, doing them all might well be a good idea.
However, @Dark Green et al know these cars far better than I, I am learning at their feet as it were.

22k miles seems a bit low to be getting plugs and coils though? I thought they were good for more like 50k, so maybe just swapping might be more sensible.

C

 

Hopefully more chime in. I will likely order coils, plugs and intake gasket in the mean time. Does anyone have suggestions on a kit? Or is everyone buying single components.

Also it looks like the Exhaust gas temp senders need replacing. Ive read they can be tough to get out. Any suggestions to easy the job. Does having the intake off simplify this project? I have no idea where these are yet