So much can be revealed by interrogating a vehicle’s electronic control modules and other systems for DTCs (diagnostic trouble codes) which are traces of faults that can significantly affect a vehicle’s valuation or even provide motive for its use in a staged collision that an examination limited to a visual external inspection can never discern.

As an example of the effect certain faults which may be discovered by a diagnostic report can have on a vehicle’s value, a mis-fuelled car can cost in excess of £7,000.00. to repair and a blocked, damaged DPF (diesel particulate filter) can cost over a thousand of pounds to repair and the presence of such faults would make the car worth significantly less than if it were fault-free.