Technical Engine sudden stop while driving

[Sailer]

New here and intrigued by the knowledge and help from members.
My 2002 camper, 2.8ltr diesel, sometimes the engine simply switched while driving. No specific situations. Sometimes this happens while cruising on the motoway, sometimes in the middle of a junction, sometimes when changing gears. Every time though the dash goes dead. Switching OFF the ignition and restarting would mostly work.
I have just changed the battery as the old one was dead (which killed the airbag computer).
Since then no further problems for a few weeks until now. Dash completely dead, engine would crank but not start.
I am at a loss, so is my mechanic. Any suggestions?

 

[Sailer]

Thank you. That will help.

 

[Communicator]

I also have a 2.8jtd. A couple of years ago while looking at the eLearn engine control diagram, E5050, I could not find the ignition switch input, to the ECU. So where do the electronics get their start up signal? The missing ignition on connection, is actually shown on the Key Code diagram E7010. With ignition on, the output from the ignition switch at pin A1, is connected to fuse F16 in the engine bay fusebox (B001). From F16, a connection is made to the ECU (M010) pin A58. This is the only key controlled input to the ECU, so it has to be the control for the ECU. However there is the Key Code system to satisfy. The code receiver (M020) does not have an ignition switched supply, but I am not convinced that it continuously interrogates the key chip, as that would be draining the battery. With ignition on, I suspect that the ECU sends a coded signal to the code receiver. This may wakes up the code receiver, which checks the key, and returns the starting code to the ECU.
With this handshake complete, the main injection relay, T09, is operated and the ECU is ready for engine starting.

The ECU, and hence engine function is also dependent upon the supply to T09 coil and contact via the main supply to the engine bay fusebox, but as the starter motor operates, that supply is proved OK.

When the fault is present, the dashboard is dead. The dashboard has both a continuous, and an ignition switched supply. This latter supply is taken from the accessories pin, B2, on the ignition switch via a blue wire, and is separate from the ignition output at pin A1.

Another function of the ignition switch is to enable the side & rear lights. The circuit is convoluted, passing twice through the ignition switch, and the LHs cab fusebox (B002). With the fault present, and ignition on, do the side & rear lights work? If not then try parking lights, by holding in the curved black button below the key, while turning the key to beyond the off position. If this does not work, and as starter operation is OK, then it must be the ignition switch, or associated connections

Another possiblity is a loose connector at the ignition switch. This has been reported previously, as causing a similar problem. There may be signs of overheating at the switch connectors.

 

[Sailer]

I also have a 2.8jtd. A couple of years ago while looking at the eLearn engine control diagram, E5050, I could not find the ignition switch input, to the ECU. So where do the electronics get their start up signal? The missing ignition on connection, is actually shown on the Key Code diagram E7010. With ignition on, the output from the ignition switch at pin A1, is connected to fuse F16 in the engine bay fusebox (B001). From F16, a connection is made to the ECU (M010) pin A58. This is the only key controlled input to the ECU, so it has to be the control for the ECU. However there is the Key Code system to satisfy. The code receiver (M020) does not have an ignition switched supply, but I am not convinced that it continuously interrogates the key chip, as that would be draining the battery. With ignition on, I suspect that the ECU sends a coded signal to the code receiver. This may wakes up the code receiver, which checks the key, and returns the starting code to the ECU.
With this handshake complete, the main injection relay, T09, is operated and the ECU is ready for engine starting.

The ECU, and hence engine function is also dependent upon the supply to T09 coil and contact via the main supply to the engine bay fusebox, but as the starter motor operates, that supply is proved OK.

When the fault is present, the dashboard is dead. The dashboard has both a continuous, and an ignition switched supply. This latter supply is taken from the accessories pin, B2, on the ignition switch via a blue wire, and is separate from the ignition output at pin A1.

Another function of the ignition switch is to enable the side & rear lights. The circuit is convoluted, passing twice through the ignition switch, and the LHs cab fusebox (B002). With the fault present, and ignition on, do the side & rear lights work? If not then try parking lights, by holding in the curved black button below the key, while turning the key to beyond the off position. If this does not work, and as starter operation is OK, then it must be the ignition switch, or associated connections

Another possiblity is a loose connector at the ignition switch. This has been reported previously, as causing a similar problem. There may be signs of overheating at the switch connectors.

Tjank you so much for outlining the possible options.
I will modt certainly keep the documents and your comments for future regerence.
In this case I seem to have been lucky. O e of the two connector plugs to the key switch ( you mentioed) seems to have been the problem. For now at least the engine is starting again.
Time will tell

Thank you all so much for your qualifed input.
I really appreciate it.

 

[Communicator]

Tjank you so much for outlining the possible options.
I will modt certainly keep the documents and your comments for future regerence.
In this case I seem to have been lucky. O e of the two connector plugs to the key switch ( you mentioed) seems to have been the problem. For now at least the engine is starting again.
Time will tell

Thank you all so much for your qualifed input.
I really appreciate it.

For simplicity, I limited the attachments to those immediately relevent. To be tidy, and complete the picture, I am adding the second sheets for the engine, and dashboard. Some of the eLearn diagrams for the x244 can be found online here. Not all of the diagrams are readable, and some of the descriptions are chopped, but by scrolling down you can link to the wiring details for tthe connectors.