Electrical nightmare

[Broadleybenz]

Ok I’ve posted abit about having intermittent starting issues on my e320 cdi w211
When I plugged car in it kept losing signal to the ecu and then got code p2506
Which wares can I check to see if any corrosion causing shorting and lose of power?
Before I send ecu away, it’s driving me mad but I’m struggling to get anyone to come out to my house and check it as the car won’t start so it’s stuck on my drive
Thanks for any help

 

[optimusprime]

Bet you have checked all the fuses ? Signal is sent to ECU via crank posision sensor ..Might be breaking down when hot .

 

[Broadleybenz]

Bet you have checked all the fuses ? Signal is sent to ECU via crank posision sensor ..Might be breaking down when hot .

Thanks for the reply, the car doesn’t get chance to get hot as it’s not starting
Very very rarely starts now

 

[Broadleybenz]

Bet you have checked all the fuses ? Signal is sent to ECU via crank posision sensor ..Might be breaking down when hot .

And yeah checked all fuses

 

[optimusprime]

Crank posision sensor as i said before,, its the little thing that sends a message to the ecu.

 

[Broadleybenz]

Crank posision sensor as i said before,, its the little thing that sends a message to the ecu.

Would the crank position sensor sometimes let it fire up tho then cut out

 

[optimusprime]

The cps plays a big part in the starting and running of the engiine . Some fail when warm or even after a few seconds of running. I have never been involved with diesel but i am sure other members will pipe in soon .So keep looking in on your post.

 

[Billwithdeadmerc]

I have the same problem. I changed the crank sensor (horrible to get at) but the P2506 fault keeps reappearing.
If you get yours fixed please let us know what you did.

 

[Accused]

Inspect the plug very carefully. I know of one where the pins were not connecting well and a new plug from mercedes cured it. Fiddly to change as you have to push the pins out sadly.

 

[Billwithdeadmerc]

Thanks for the steer.
I got back to the plug after stripping the insulation at the back of the engine.
The connections look fine but I used contact cleaner before reassembly.
The engine starts and runs fine, ( the engine normally refusing to start with a duff crank sensor, which is why I changed it before)
However the warning light still comes up, and the code P2506 is shown on my reader.
I can reset it and the light stay out for days, but then suddenly reappears, normally after a cold morning start, but sometimes after 20 minutes into a run, including to the last MOT.
Any More Ideas Of What To Try Next???

 

[mersum1es]

err.. what is excactly P2506. A bit difficult to remember name and description of 10000 code numbers... also don't mention age of your car either, so IDK is it OM648 or OM642 engine... what code reader you are using? Can you see sync info at starting?

 

[Broadleybenz]

Thanks for the steer.
I got back to the plug after stripping the insulation at the back of the engine.
The connections look fine but I used contact cleaner before reassembly.
The engine starts and runs fine, ( the engine normally refusing to start with a duff crank sensor, which is why I changed it before)
However the warning light still comes up, and the code P2506 is shown on my reader.
I can reset it and the light stay out for days, but then suddenly reappears, normally after a cold morning start, but sometimes after 20 minutes into a run, including to the last MOT.
Any More Ideas Of What To Try Next???

When you say engine rufusing to start what was the car doing? Was it even cranking over? Glow plug light?

 

[Billwithdeadmerc]

Last spring, in the middle of a long journey, I stopped for refreshments, and found that the car would not start at all, it cranked over fine, but no sign of life.
The RAC could not fix so I was transported home, after 9 hours of waiting.
My fault reader pointed me to the crank sensor which I replaced in about 4 hour frustrating work, trying to reach it by touch only.

All has been fine since, but now I am getting this warning light coming up every few days, and my various code readers all come up with the code P2506.
The car starts and runs with the fault, and I can erase the fault easily, especially during my last MOT.

So I am at a loss as what to do next.
Bill