Have a 2012 Ducato 130 that won't start. We have traced the problem to no power coming to connector on fuel pump, when engine is turned over. Bit of a history to this van, was bought at an auction as stolen recovered, but it looks like a few different people have had a go repairing it before we got it. Any way, it will fire up with easy start, so engine is all good. Have had Autokey re code the ignition to the new keys. We have fuel coming from back to filter and on to the pump OK. Checked fuses and relays. Cleared codes only 2 left P0667 - Voltage after main relay, and P2100 - Throttle actuator. Van is in my local garage, but he's a bit stumped with this one. Any one could point me where to look next, would be very much appreciated.

Sorry the code is
P0657 - Voltage congruence before and after the main relay - Present
P2100 - Throttle actuator - Present

Is the low pressure fuel pump running for about 20 seconds after turning on ignition?

You should here the noise coming from floor between cab seats

Yes it is, have fuel all the way to the high pressure fuel pump. There is no voltage going to the 2 wires on the H/P Fuel pump when the engin is turned over. There is a constant 0.3Volt there.

WE had a 2008 130 Mutijet which had a starting problem which was eventually tracked down to a broken cable between the ECU and the low pressure fuel pump. The OBD codes were useless first of all indicating the fuel regulator and then the fuel pump itself. The fact that you have 0.3v at the pump implies something similar

Yes I think your right, becaue when I remove the left block connector from the ECU, the 0.3volts goes to 0 volts. I managed to get a workshop manual on ebay, going to try trace those ECU wires back to high pressure pump and/or relay. These wires plug into the regulator valve on the H/P Pump, getting a reading of 2.5 ohms across the 2 terminals on the regulator valve, suggests the pump is fine.

Look's like the wiring pin out is fine between the H/P Fuel Pump and the ECU. I was not the first to test this as I could see the pin marks in the wiring connector at the ECU end. Going to bring the ECU back to the guys at autokey who setup ECU & ignition a few months ago.
So Pin 3 & 19 on the ECU Left connector are not sending out an voltage to the H/P Pump.
I also took off the Fuel Pressure Control Valve from the Bosch H/P and tested it with a 9v battery, it's clicking fine.

Latest is that I sent the ECU back to Autokey to check it, but has come back and now the lock is back on the dash. Getting nowhere fast.

Found an ECU with same model No as mine on eBay in the UK, with keys and BCM, awaiting it's arrival.

". I was not the first to test this as I could see the pin marks in the wiring connector at the ECU end. "
This rings alarm bells to me....testing a wiring connector and leaving pin marks indicate "Mr Bodge It" has been near it with his Maplins multi meter and probes that are way too big to fit in the connector .....check that all the female connections are good and tight , I've seen loads of wiring problems caused by ramming multi meter probes into multi plugs.
You have narrowed down which wires and pins are in the circuit , try running wires straight from the ECU to the PWM on the HP fuel pump .
It's a PWM (Pulse Width Modulation Valve ) so you won't see a constant voltage from the ECU so it will give strange readings on a normal multi meter.....you need a scope to see what is happening or need decent diagnostics that can read what the ECU is sending and receiving and also if any Rail pressure is being generated as you crank the engine .....if the ECU isn't seeing what it wants then it won't send a signal to the injectors to open .

Had exactly the same on my 2008 multijet. I cut out the broken wire and put in a new bit, all sorted for just a few quid.

Seems quite a common problem with these, maybe worth a sticky thread on the forum??

Seems that a fuel relay is missing from the passenger footwell, the grey/red connector. dose anyone know what this Black/Yellow connector plugs into? Same area near passanger foot well / battery box area.

Well.. have just spent the week chasing Alice down the rabbit hole....This item that plugs into the red and grey connector (passenger foot-well) is NOT a Fuel Relay, Its a Door Central locking Relay. This can be verified in the workshop manual. Yes I know, there are 20 of them for sale on eBay All saying Fuel Relay, but has anyone bothered to check? There are 4 types L1 to L4 depending on the number of doors on the van......
But, after 3years 7Month's and 29days 15 different "techies" looking at it, the van is running.

Hi mate!
did you started your van?

I got same problem on my 2017 fiat ducato 2.3 mjd, with MJD 9DF ECU, it showing p0657 Trouble code, and i think it internal problem with ECU, it not sending power to hi presure pum regulator...
and if you sorted your problem, can you let me know, what was wrong with your van???
thanks in advance

My problem was a broke wire in the wiring loom, from the ECU to the fuse box, it was one of the wires on the fuel fuse, I just went through them all with 2 pins and a meter until I found the broken wire. It's well documented in the camping forums (Ducato Campers) wiring known as "The Rusty Junction".