MPPS Jetta 4 1.9 TDI deleted key

[ghostridersa]

Good good members of DK

Can any of the members help me understand what went wrong? Yesterday I had a VW jetta 4 1.9 TDI in my shop and I connected MPPS V5 to it and just read the dump to use on another car.

After I read the dump and disconnected the MPPS the car wouldnt start and with vcds I checked the measuring blocks and found that the key had been deleted. How is that possible with MPPS by just reading the dump? Can anyone explain this to me please?

(I rematched the key and the car started)

Thanks in advance

[z786]

what year was the car

[ghostridersa]

It was a 2003 model 1.9tdi

[z786]

that would be the same as a golf mk4?

iv seen a few where voltage spikes deletes the keys, maybe you shorted obd connector also check if it has an after market radio, that cud cause problems