Electrical problem - problem with my E class

[lloyd harris]

can anyone out there help me, since May last year my E class has had an occasional problem, you set off and can travel a few mins and then the car will cut out, it sometimes flashes up a message ECD diesel electronic.  you then have to use the key fob to reset the alarm on the mirror and then you are able to restart the car, it may only do this every few thousand miles, or it may do it twice in a day there is no pattern, sometimes you can be driving along and the car will give a lurch and almost stop, if you kick down fast you can sometimes keep it going, the message flashes up for a few seconds and then disapears.  Car has been into main dealers and on machines many times, they have no answers, just say the next thing they could "try" is to change the fuel pump, this will be very costly if it does not cure the problem though.  I have lately disconected the alarm and all the fuses that I can, but it is still live and the problem is still intermittant - any ideas please?

 

[Anonymous]

Electrical problem

The diagnostic should be accurate to a given sensor.
The pump rack position is monitored internally by a pair of hall effect coils, one with a fixed core and one with a core attached to the rack.
There is a hall effect speed sensor which detects from the pump cam ring.
I think the problem will be a bad connection either at the connector or in the wiring loom.  Try wiggling the wires around.  Alternatively one of the coils is faulty.
A visit to a Bosh diesel specialist would be a good idea as they see these pums in more applications.