Just on the off chance....

After so many times connecting to the OBD2 it is possible to crack the OBD2 block and not get connectivity to all modules and possibly ground out one or more wires giving you problems. (ask me how I know)

I found out only by accidentally wiggling the NT-510 cable in the plug because my DME wasn't showing. A trip to the boneyard and a long time under the dash fixed it.

Sent from my SM-A730F using Tapatalk

You need to test with more power. I fear your battery even when fully charged isn't supplying full voltage to the support modules and the starter.

Does it crank slower than normal and have you measured battery voltage during crank.

If you have a peak reading multimeter, measure the voltage from B+ under the hood to the positive in the cigarette lighter. Should be about 1 volt on a diesel (3/4 v on M54).

When a starter starts to fail it often just takes more and more current until the battery voltage sag is so bad you get abs or trans failure from low voltage.

Thanks for all the feed back. I will invest in a new battery and see what comes of that.

Before you install new battery, charge up the current battery and get a current draw on the starter. If the starter is worn or can pull double the current, over 600A and it'll pull the battery voltage so low it won't matter how good the battery is

Hey Kshamm - did you ever get to the bottom of this? I've essentially got the same problem and it's sending me a little crazy.

Hi Ausbmx. I’m sorry to say I never did. I ended up selling the beast to a guy that was pretty confident he would fix it straight away. He too has still
Not fixed it. My gut feeling in the end after all of my research and diagnostics was that the ecu had a gremlin and it was not worth the time
Or cost in repairing it hoping that it would work. Sorry I couldn’t share a more helpful response.

Ahhh damn! If you don't mind, can you remember all the things you changed/tried to resolve it? I get the feeling that it is likely electrical/ECU related too.

Next on my list are probably:
1: New fuel regulator on the back of the rail
2: Replace all relays, even if they test out okay.
3: Flow control valve on back of HPFP.
4: Go to the wreckers/junkyard and get another ECU and see what happens...

To summarize my issue first.

Car would not prime on turn the key to position 2, I would turn back and forth between position 1 and 2 until I could here the pump prime and then I knew it was going to start, this happen once or two a week in the beginning until eventually it would not prime at all.
It was throwing multiple codes but none that really helped


Tasks I tried to fix the beast ( If I think of anything else I did I will reply again)

New fuel rail sensor ( front of engine)
Checked/swapped every single related relay/fuse – visually and with a multimeter
New in tank fuel pump
New battery
New fuel filter
Removed/cleaned the injectors


Things that were next on my list before I decided to cut my loses



New fuel pump regulator ( the one that is fitted to the HP fuel pump)
A packet of matches ( to burn it to the ground)


Items that had been suggested to change/check but I never got to

New key


Like I said though, my gut feel was it was ECU related and I just was not going to keep throw money at it in the name of hope.

Ignition switch ??

Or maybe the ring antenna for the EWS?