I have a 1996 Mercedes-Benz E300 diesel.When driving it will just shut off,as if the key was turned off.If I got out of the car, locked it, and then unlocked it,it would start up again most of the time.The red and green lights in the rearview mirror are flashing when the car will not start. If the car sets for a while it will start up again.I've gone to 3 M-B mechanics and none can figure it out.Any info would be greatly appreciated.

Hi,

This car has a known fault with a relay that causes these exact symptoms. The relay is responsible for fuelling and typically develops an intermitent fault causing the vehicle to stall and then restart after a few minutes.

The suspect is the K40 relay in the module box under the hood next to the passenger side hood hinge. This relay costs around $160. Additionally a faulty K40 will not store codes in the ECU and I presume a diagnostic scan has already been performed when you have already had the car in with Mercedes.Other issues have been known to develop with the wiring harness that eventually disintegrates through age and ends up sending intermittent faults to the ECU.

However, a wiring harness is an expensive fix and given how common the K40 relay issue is with this car I would advise this as the first issue to investigate.

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