Technical Poor running/low power P2146 fault

[Sylvester22]

The supply to the engine bay fusebox must be securely connected.

I am sorry as your contribution is well intended, however you appear to be confusing the layout of the OP's 2019 vehicle, which has the starter battery under the cab floor, with the much earlier x230/x244 models that have the battery at the RHS of the engine bay. On post 2006 models with starter battery under cab floor, the battery negative connection is also a chassis earth point. The notorious engine block earth strap is also a feature of these later models and is part of the main current return path for the alternator, and starter.

It's not the fuse box, it's the + or - clamp on the battery, looks like 1 nut is missing, but I've asked on this forum months ago, and was told only that 1 bolt isn't supposed to have a nut on it. IT WAS FOR 2010 BRAVO 198, HENCE I WROTE IIRC.
It's in one of the early threads I'd posted when trying to solve electrical shut-off issue. In my case turned out to be a damaged ECU.

For the Bravo 198 under the battery tray there's a very thick earthing cable wjich tend to shred and cause issues, hence I recommend to check in case OP's car has the same/similar.

 

[Andyspen11]

Oh ok!
What you mean remove the battery and have a look underneath it?

The supply to the engine bay fusebox must be securely connected.

I am sorry as your contribution is well intended, however you appear to be confusing the layout of the OP's 2019 vehicle, which has the starter battery under the cab floor, with the much earlier x230/x244 models that have the battery at the RHS of the engine bay. On post 2006 models with starter battery under cab floor, the battery negative connection is also a chassis earth point. The notorious engine block earth strap is also a feature of these later models and is part of the main current return path for the alternator, and starter.

No problem and thanks for your comments, I’ve added a nut to the mains lead in the fuse box and I’ll check under the battery in the cab for any earth cable issues

 

[Communicator]

No problem and thanks for your comments, I’ve added a nut to the mains lead in the fuse box and I’ll check under the battery in the cab for any earth cable issues

Do not strain yourself removing battery. Judging from photos that I have seen previously, the battery earth/negative connection should be an obvious short braid. While in there, worth taking to opportunity to check that fuses and battery positive clamp are secure.

Observe sensible safety precautions by following the shutdown procedure, and then removing battery negative connection, before using tools on positive connections.