Hi folks,

I'm hoping there's an expert out there that might be able to shed some light on an issue I'm seeing with my car.

Car is an A6 Allroad 3.0TDI Quattro and a few days ago I fitted a new battery. On first start up after this there were a number of warning lights that came on and a message to say there was a Tire Pressure System Malfunction. I did a quick Google and it didn't seem uncommon for lights to come on after a battery change and the suggestion was to start driving and they would go off. And this is exactly what happened.

However, it's a couple of weeks later and sometimes when I start the car I get the same warning lights come on. The Tire Pressure malfunction warning comes back along with the ESC/ABS warning light and the Engine Control malfunction light. The first time this happened was just after setting off driving. The car lost all power and was rolling to a stop. But worryingly, the car slammed on the brakes - emergency stop style. I was thrown forward with enough force to lock the seat belt even though at the time the car was probably only doing 10-12mph.

Yesterday I had a very short journey to make in it and it did the same thing again. Only this time there was someone behind me and it was only their quick reactions that prevented them from running into the back of me!!

Has anyone heard of this before? The car applying the brakes by itself? And with such force that the car screeches to a halt?

The issue seems intermittment and is only since changing the battery. Needless to say the car is parked up and won't be used until this is resolved. I don't want to think about what might happen if the car whacks on the brakes when travelling at a higher speed!

Thanks in advance for any pointers.