lotusGT3

I have a 996 GT3 that is in the workshop for suspension works. The battery went dead flat and the workshop tried to jump start with no luck (slow engine turn over). They connected large battery with good leads and jump started the car and it ran fine. They cleared multiple fault codes due to cranking with flat battery BUT could NOT clear ABS fault 4266 being RETURN PUMP FAULT and the ABS light is illuminated on instrument cluster (brake distribution fault & ABS fault circulate).

Importantly need to add that the ABS pump under the hood runs continuously with or without the key in the ignition and when engine running.

The ignition switch was replaced within the last 6 months (1,000 kms) and the car is not used often.

Anyone come across this issue before or have any thoughts on cause or cure?

Thanks in advance.