Hi all, I wonder if I could get some advice. I have a 04 X Type 2.0 Diesel with 72,300 miles and I have what sounds like a ECU faulty. Problems go back 5 weeks ago, was driving it and the car cut-out and would not restart. I did have a flashing glow plug light. So towed it home, and read the code and it was P0251. So checked hoses for splits, changed fuel filter and the car started, but with loads of black crap on the floor under the exhaust.


Took for test drive, drove fine, so took it to my friend's garage to diagnose the fault further as I was going away, so left it with him. He changed a pressure sensor on the fuel rail, as it looked like that was the fault. So he changed it, took it for a drive and it broke down again, same as before, so he towed it back and to try and get it to start, he tried apparently many times to jump start it, with boosters, off cars etc. But now it wouldn't turn, just dead like immobilised.


On the dash it was showing security failed, so tried a battery no different. ran power to the back of the starter from battery, and it turned over but wont start. So towed it to a independent jag garage, he plugged in with a machine, and could only test 70% of the ECU before it failed. so got a program to flash to it, and it got to 80% and failed again. So thinks it ECU have died from the jumping of the car so much.


Now my question is, if I get a second ECU, Ignition transponder unit and chip for the key, if I swap all that from my dead car will I need to get anything coded? as I was told by a Autolec that if I do that, it will work and car will start. But I thought the injectors were coded like a ford, and I also thought the pump was coded, but apparently the ECU will find those setting itself. Anyone offer advice on what needed for ECU change, I be grateful as I was quoted £720 for a new ECU. Thanks.


Anthony

 

Oops sorry, just noticed further down there is a diesel variant sub forum. If this is in the wrong place, can a mod move it please. Thanks and sorry.

 

I have reprogrammed an ECU on this model but it wasn't from a different car, it was the original. I can say for certain that the Injector codes are required during the programming. The injector codes are printed on a label that you will see if you remove the plastic engine cover.

As far as I know the injector codes are only calibration factors. So I don't think having a wrong set of codes in the ECU would cause a no start but may cause it to not run 100%. I don't think the pump does need to be coded.

However you will need programming to match the ECU to the Security system and to the ABS module at least - that's if it can be re-programmed at all. The ECU does hold the cars VIN no. so I don't know how that would be dealt with.

Having said all that, your post said that the garage "think" the ECU is dead. I would want much more than that before going down that route. I would want to ensure that there is no intermittent wiring problem between the ECU and the Data Port that may be causing the connection problem (and possibly your original problem also).

IIRC the connectivity from ECU to DLC (Data Link Connector) goes all the way down the RH side, under the radiator area, back up the other side to inner wing, in through the bulk head and on to the DLC. Lots of scope for problems.

I worked on a 2004 2.0D that had a similar no start condition to yours along with the Security failure message (but a bunch of other CAN codes also). The problem with that car was traced to a broken CAN wire in the loom under the radiator.

Good luck whichever way you go.

 

Thanks for that advice, this is why I am thinking of having the car back for a minute. As he only said 80% sure it is the ECU. But that is something for me to check regarding that broken CAN cable, be worth a check first. Thanks again.

 

Right an update, I had a mess yesterday. had the car back, so I thought I would go through the fuses as even though he said he checked them, for 5 mins its worth it. I find the fuse in the engine bay for the ECU had blown, so I changed it, locked and unlocked the car and the car came to life and started, but cut out after 5 mins of running.


Had a look again today and it started, but cut out after a few mins again. got it started, checked by fuel filter, and when I touched a pipe it cut. So I got a gallon of diesel, run a pipe from the can, to the where the main pipe goes on the engine, syphoned up diesel, attached with jubilee clip and the car started easier and ran OK.


So got a pipe at scrap yard, changed it and the car run fine for 10 mins, drove it around for 10 mins, fine. came back, ticked over again, out for a run and great drove lovely. Got back, ticked for 5 mins cut out, same as before turning, no start like its getting no diesel or is sucking in air.


I am guessing that I got air being sucked in somewhere, or some crap in the pipes. The filter is full of diesel. I am stumped now. Any ideas would be grateful now. Thanks.

 

So good news then, at least you're not messing about trying to put an ECU in and still not fixing your problem. So you're back at square one.

The original code you posted is specifically a fuel related problem (no surprise there). It is for faulty Fuel Metering Valve (or circuit).

I don't know much about this valve personally but a quick look in JTIS suggests

1. It is located on or around the fuel pump on the inlet side
2. It has a small integral filter that could be blocked
3. It's a simple solenoid valve with 2 pin connector.
4. Looking at wiring for it it looks like 12v supply with Key on, on GY wire and a switched ground from the ECU on BU wire
5. I suspect it's a PWM signal from the ECU to control the solenoid so getting true readings of the signal may be difficult depending on the quality of your Multimeter
6. Testing of actual solenoid is restricted to resistance tests

Download the manual/wiring diagrams from the Stickys section and have at look at the above. There is a section specifically for testing this valve. If you struggle downloading/installing it I can post the relevant section here.

Note also that there is nearly always alternative root causes so just because the code says faulty Fuel Metering Valve does mean it really is that, but it's obviously the right place to start.