Good morning, we bring you another case that has reached the Technical Help Desk, and here is what the customer told us:

"I have a problem on a 2004 Audi A4 2.5 V6 TDI, after replacing the battery, due to the malfunctioning of the battery in the car (the customer forgot to turn off the headlights), it does not start. After carrying out a diagnosis, I found an inconsistency in the engine control unit: the unit does not seem to recognise the car.

Have you, dear colleagues, ever experienced a similar problem? What could be the problem that causes this anomaly, and thus does not allow the vehicle to start?

We thank you in advance.

The editorial staff.

• v6 tdi