5V reference wiring diagram

[nver]

Hi

Can anyone please share 5V reference circuit 'C' wiring diagram for 2009 Ford Fiesta 1.6 TDCi ?

My problem:

The car is not starting and got DTC P0698 with MIL light on the dashboard.  I checked the 5V VREF at EGR valve connector PIN1 and multimeter is reading 0.25V  which seems like the real issue. Very intermittently this goes back to 4.9/5V and then car starts.

I tried a new EGR but didn't fix the problem, also I disconnected harrness from EGR and still 0.25V on PIN 1. So looks like EGR is OK.

What I would like to try is to disconnect other sensors on the same 5V bus to confirm which is bad (if its a sensor issue at all ). For this reason I need the wiring diagrams please.

Any other suggestion is also welcome.

Many thanks

[tomshepp]

Is that reference the source? Anything sinking the reference current to that extent will be obvious once disconnected. Go round the engine bay and pull the connectors one at a time then replace them as you go. There will not be more than a dozen.  You do not need a diagram. Just keep checking the voltage until you find the short. Give each connector a good wiggle as you go. It could be short inside the wiring.