Ford Fiesta 1.4 TDCi 2002 - Recovered, Non start - Ongoing - Fixed #
Posted by Christopher Taylor on April 8, 2013, 9:46 am
Year of Manufacture *: 2002 Engine Size and Code *: 1.4 F6JA ( Optional ) ECU Type: DEC ( Optional ) Scanner Used: KTS340
Can you help guide me in the diagnosis of this non start Fiesta? It arrived on a tow truck and was recovered from the motorway hard shoulder. I charged the battery and read the codes with my DEC. Six codes were present: P0087 Fuel pressure, P0116 Engine coolant temp sensor, P0571 Brake switch, U0155 No instrument panel comms, U2510 CAN,Invalid data for vehicle security and finaly P0002 Fuel volume regulator control circuit. The last of the codes (P0002) fuel volume control circuit is the only reoccurring code after cranking. Having established that the engine would run briefly with a squirt of brake cleaner I have spent time checking a fuel sample which I am happy with and testing the fuel rail pressure sensor output on the scope. There is no fuel pressure in the rail on cranking. I can see no problem with the wiring or connections between ECU and either the fuel volume solenoid or pressure reg. I have good feeds to both and patterns to suggest the ECU is in control. The way I understand this system is the ECU has control of both the pressure in the rail by way of the pressure regulator(short fat solenoid) and the volume of fuel via the volume solenoid (longer thinner solenoid). I was thinking the volume control was a way of reducing pumping losses like third piston cut off on Bosch Peugeot pumps. To remove excess work on the pump when it’s not needed. Correct me if I’m wrong. I have substituted the volume control solenoid. I would like to know what steps you would take next. Is there a way of closing the regulator and opening the volume solenoid to prove that the pump still pumps? The pump is made by Siemens. So presumably when I crank the engine the ECU closes the reg and after a bit of cranking the ECU then recognises the low pressure signal and stores P0002 volume reg circuit ? That does not sound correct to me. Why not P0087 “fuel rail pressure”? It seems unlikely to me that the pump has failed whilst in the fast lane despite 100000 miles and eleven years of use. Is it more likely the pressure sensor has failed? Could I have an ECU fault? Like all of us I would like be accurate in my diagnosis without replacing parts unnecessarily. Removing the pump for testing would be a big job too. Short of information so your help as ever welcome. Thanks Christopher.
It has one of those large rubber priming bulbs which goes solid after two or three squeezes. Tried squeezing whilst cranking. Seems it must have enough on cranking I think.
If you are happy with the low pressure (I would prefer to fit a gauge in line) then deadhead the pump and monitor the duty cycles to both the high pressure reg and the flow reg whilst looking at the pressure generated by the pump.
If all is good then the fault lies within the high pressure vessel after the pump, if not the pump needs further investigation.HTH
Thanks for reply. The trouble I have with testing this design is the pressure sensor is on the rail. The rail has one feed from the pump but no return. So the pump returns excess fuel. Dead heading the pump would isolate the sensor. In the end I took a closer look at the pressure sensor output whilst the engine ran on brake cleaner and noticed a small increase in pressure. As I was still getting a returning code for fuel volume circuit I once again checked my testing to prove beyond doubt the wiring was sound and load tested the loom with my trusty big bulb. Bosch ESi information does not make it clear if the fuel volume solenoid is energised to open or close. I tested the solenoid with the airline and established that when energised the solenoid passes fuel. Finally I realised that although the pump was sucking and the low pressure side was providing fuel the pump must be starved of fuel on the high pressure side if the volume solenoid was not energised on cranking. Next I briefly took ECU pin M4 on the centre terminal block to ground whilst cranking and the engine started immediately. The ECU is presently away for test and hopefully repair. I will post some waveforms of the expected patterns soon.
ECU returned from electronics company and Fiesta started. No returning fault codes after roadtest. Images of scope patterns taken from volume solenoid, pressure regulator and injector at various engine speeds posted on waveform forum.
on April 8, 2013, 1:03 pm, in reply to "