DAF CF75 Exhaust System Fault and Engine Limp Mode

Hi, I have a 2012 Daf CF75 here. It has been for sale the past 6 weeks or so and is now sold. In the time it has been for sale it hasn’t been doing any work with just the occasional moving around the yard.
It has to be taken for respray tomorrow for the new owner so today I went out and started it up to check it over.

Upon start up, I’ve now been hit with 3 warning lights:
Exhaust system warning
Engine warning
Engine limp mode

Adblue tank is full but the gauge is reading empty.

Has anyone here experienced the same issue and know the fix for it?

Any advice much appreciated.

I hooked it up to Delphi and got these Fault codes
U0113 - CAN , message frequency from AdBlue system is too high/low - intermittent
P2100 - Engine derate active because of fault in AdBlue - Intermittent

That code is for a short circuit in the can wiring where is the question…The short loom is prone to failure.water may have got in the plug there is joins the main loom