*****@******.*** 2008 ford kuga 2.0 tdci engine code G6DB NON START - TOWED IN BY AA. scan code P0090 : FUEL PRESS REGULATOR CONTROL CIRCUIT - no change in the signal - this is detail give by snapon modis ultra. Live data shows no fuel pressure (or very very little) Have checked wiring diagram (using AUTODATA) for a FOCUS with same engine code. From what I can make out we have got a 5v circuit on the 3 wire (B186) "Rail pressure sensor" we have a 12v supply to the big solenoid on the main pump and (I think) a suitable ground switched pcm driver signal (duty cycled) to operate it. I am confused to know what is the difference between the (Y194) "fuel flow control valve" AND the (Y63) "fuel pressure regulator control solenoid" How do these three items relate. Is there a common problem/known fix. The car cranks over fine. Won't fire. It is definitely well overdue a service (air filter filthy etc). Owner noticed a slight poor start a week or two ago. Stalled and would not restart after 50 mls journey. It had been idling a several minutes before that. Service light on. any ideas welcome. jamie
ps. I have 2.4ohms on big solenoid (Y63?)
yep thanks for getting back to me...I think ive sussed it.
I like to check that the signal for the suspect part is still good. i.e. the ecu driver is still good. I wasn't sure why the fuel pressure was zero. but it wasn't lack of fuel as we bypassed the supply and still no go. Fault code p0090 pointed to fuel pressure control circuit. Couldn't find a wiring diagram for the KUGA on autodata but found the exact engine match on a Focus and that had diagrams. wire colours matched etc. Of all the sensors and actuators on that circuit I went for the three main ones that would cause a non start.
A. 3 wire pressure sensor on rail 5v - yes, earth, yes, didn't check signal.
B. 2 wire solenoid on top of pump. Ohms good 2.4, signal when cranking....well some sort of earth switched duty cycle going on, power 12v supply good (ignition on)
Thats where I was when I contacted you.
At this point I thought I could get scope feed and check wiring continuaty by access ECU. In a plastic box behind the NS headlight. This is fully sealed and rivoted together, looks like you have to break it to open it.
Decided to check out the final solenoid (C) which meant removing battery and airbox etc.
this solenoid is at such an angle I made up a loom to check resistance - good.. 2.1ohms (all this data is available on Autodata - as a Focus)
Just about to set up to check the power and signal when LO AND BEHOLD!! broken wire.......
Will keep you posted if I haven't bored you yet. Jamie