Ok, coming to the party late and I haven't read the thread fully so sorry if repeating. Read this:
We recovered this car with a flat battery the customer who had bought his own cheap battery of ebay.
It was knackered. The car sat outside whilst we waited for him to get the battery replaced.
We fitted his new battery and I insisted he have the new one (battery / starter / charging test) tested, a global scan codes cleared and all reset done as needed.
He drive the car a away without faults. Two days later he has a cranking no start situation, so we pulled the car in again.
Crank no start and no oil pressure light on dash. No activity at either low pressure pumps (tank and engine bay).
Another global scan showed P1260 delivery fuel pressure monitoring P3505 Glow system on ECU.
P1605 - A/T ECU EEPROM error on transmission
28H/40 - undocumented code
C7 - tank level sensor
F8 - CAN Data Error from DME/DDE
F6 - CAN Data Error from DME/DDE
F7 - CAN Data Error from DME/DDE
All on instrument cluster
Cleared all codes and rescanned (all units) at KOEO only the two ECU codes returned. Same code result after cranking.
Chose to ignore glow plug code and focus on the P1260 and the lack of pump activity.
Ran and actuator test on FP relay and Oil pressure light neither responded or activated.
Tested FP relay in relay tester and operated fine under load.
Relay should be switched to earth at KOEO by ecu all +ve at relay present and correct but switch earth missing.
Pulled scuttle panel (all clean and dry) and load tested earth wire - relay to ecu. No fault found. Scope at earth pin on ECU no switching to earth.
De-pinned earth and fed separate earth to relay down de-pinned wire from engine bay - bingo both LP pumps join the party. Initially wouldn't start on cranking.
Went to lunch left the battery on support - came back after lunch to the same result.
Live data showed 3.54bar on fuel LP (to spec) so it should start. All other fuel data in pids showed zero so I thought maybe the pump and rail were empty still for some reason.
This is where it goes wierd.
We did nothing more than try cranking a few times with and without our new relay earth connected.
Cleared codes again left LP pump running for 10 secs the car started - left the car running for five minutes whilst checking live data - all live data as should be all through rev range.
So I am thinking have we got an ECU fault or a start command fault.
So refitted FP relay pin back to ECU and tried it again - started on the button - so now I am baffled.
So I thought I would see if the code P1260 definition was correct (verus's reputation and all) - but the jury seemed out, some parties say its immobliser and some say LP fuel
So put the car back in car park to let go cold and looked up code definition. Went back to car to do a cold start - no start and no LP pumps running.
Locked and unlocked the car 4 times - it started sweet as drove it back into workshop. Rescanned and only the P3505 glow plug code recorded.
So I haven't had the in-tank pump out of either side to check.
I did low amps both low pressure pumps to see if I had a failing armature - under bonnet pump 5.5 to 6 amps no nasties - but in tank pump showed 2 peaks at 8 amps then 2 at 9.2 certainly wasn't consistent - so could be a possibility of the motor parking in a high spot. Both pumps run off the same circuit and together its only 15 amps draw.
Right now the car starts every time on first rotation of engine so can't fault it - but I haven't found the problem. So am reluctant to give it back to the customer.
Thanks for all your input so far - I think Prince has given me my next tests. So I must verify the code definition and see what I get with reader coil disconnected.
I hope this all makes sense.
From this thread
http://206.72.115.172/forums/Topic145401.aspx
I was most interested in the earth cable to relay part, but make of it what you will.
Cheers
Mike