A week or so ago my 2012 Jaguar xf 3ltr S took 5 full attempts to start after that it ran normally for a week being used daily and starting normally. Whilst driving in heavy traffic a warning message popped up but before I could read it the engine cut out and left me with heavy steering and little braking. Be registered for break down service I was attended by a mechanic who after numerous tests cleared the fault codes and attempted to re-start the car. This failed and the car is now back in my home garage. The problem was thought to be the in tank pump or a blocked fuel filter, both have now been replaced and no fault code show with the Ecu checker. I still wont start even though correct pressure is shown at the injector rail. What else can cause this problem. The battery is in very good condition and the diesel is clean.

 

It might be the brake pedal switch, not that expensive to get a new one and easy to replace if you are a 90 lb contortionist. Those of more normal size and weight will struggle to do it.
Try pushing down really really hard (and I mean as hard as you physically can) on the brake pedal while you press the start button and see if that works to start the car.

 

That would seem to need 2 faults occurring at the same time - the other being whatever caused the engine to cut out.

More likely the latter is the only fault.

 

Thanks for the suggestions to date I am going to change the ignition Reader ECU Module Unit tomorrow and see if that cures things and will also check the under brake pedal switch but as the car cut out whilst driving hold out little hope. I am new to any kind of forums so excuse delays in reply's or lack of detailed descriptions. I have been a jaguar owner since 1963 first jaguar owned was a 2.4 mk 2 followed by non stop model changes to date.

 

The what now?

Bear in mind the modules seem about the most reliable things in the car...