Engine complete shut down ...

Hi own a 08 d40 with 90000km on it and never had any engine problem , but just got back from a trip up north and traveling on corrugated roads about once every 100km or so the engine would shut off while cruising at 50 - 100 kph . would turn straight on after stopping the car . Ive been under the bonnet a shackin the hell out every connection and wiring loom possible but cant get it to shut down . Does any body have some ideas what this could be thanks

That's a new one.

When you say "the engine shut down", was it ONLY the engine that stopped, or did the instrument panel go dead as well? Did any of the lights work while the engine was shut down or did EVERYTHING fail?

The answer could be anywhere. If it was just the engine, but everything else was working, you could have any problem from a dodgy fuel pump (or its electrical connection is dodgy), a loose CAS (Crank Angle Sensor), a bad earth on the motor preventing the injectors from firing ...

If it was everything, you might have an intermittent connection on the main fuses, it could be an ECU fault (maybe even a cold solder joint in the main board on the ECU) - it might be the ECU fuse, the BCM fuse or the BCM ... the list goes on.

hi tony , Every thing just like i turn turn the key off ...even the speedo dropped straight down 0 kph

The speedo isn't like the old days where it was driven by a cable from the wheel or the gearbox - it's electronic, driven by the ECU that takes an aggregate reading of all 4 ABS sensors to work out speed and distance travelled.

But ... this means you're not looking at something expensive like the fuel pump, or something tricky like the CAS.

First thing I'd do is check over all of the fuses and fusible links. Pull ALL of them out and examine them. I'd pay particular attention to the ECU fuse inside beside the glovebox (right column, top fuse). The action of pulling the fuse out and putting it back in will clean the contacts - but look for any surface corrosion or powder-like stuff. It might be that simple.

If the fuses look ok (as well as the big fusible link hanging off the battery's positive terminal), check the battery terminals themselves that they don't move. They're supposed to be clean, and nice and tight. Follow the negative lead down to where it connects to the engine and undo it, make sure it's clean and do it up again.

If you're still having problems it's possible that the battery itself has an internal problem.

There's a couple of things to start with, anyway.

Thanks again i will try what you have mention and go over everything again to double check will keep you up to date if i have any luck ..