Hard fault codes are:
Accelerator Pedal position Sensor Plausibility. 5v and Earth are Present at the pedal. Below is a capture back probed at ECU on the 2 signal pins
That is self explanatory, its faulty or the wrong part. It was loose and unplugged when I first looked at the car. I'm thinking that this is not the cause of the non start but a quick easy fault to test.
I have a Swirl / Intake Runner Flap fault that I have ignored for now.
30BB - Injector Output Stage Fault which is set at Ignition On - Without Cranking.
I have Load tested ECU power Supplies and Earths, they are fine. disconnecting all 6 injectors and then re connecting one at a time makes no difference, shorting each Injector to ground also does not change anything. Always the same code.
Fuel Pressure Hits 150 bar + at cranking.
At ECU Plug (disconnected) I have checked resistance of each Injector and I have a steady 194kohm. Next an insulation test to earth from each pin with the tester set at 100v then 250v I have a resistance to earth of >20Gohm..
Next I put an Amp Clamp around all 6 negative wires to the injectors and another channel (with attenuator) to Injector 1 +. Fault s Cleared and then tried to capture Voltage to Inj 1 and Current to all 6. Absolutely nothing other than some interference. Hoping to see whatever it is that the ECU does not like (externally)
I'm thinking the ECU is Faulty, the damage is internal and of course cannot be seen by the scope connected externally.
Question is, is there anything more I need to check before I send it away for repair.
Without the fault codes as well I would be suggesting to check all sorts of reasons the injectors are not firing but with the code you are probably right - have a look at the technical bulletin for the N54 engine here. I know its the wrong engine but the tests / checks are probably going to lead you to the same conclusion.
Without too much research, It may be the wrong Engine but I suspect it is the same or similar Management System.
I took the Lid off it today and I can see a Surface Mount component that has fried. Now, I need to work out if that is "cause" or "consequence" Something tells me It has a bad Injector that is the real cause.
Tomorrow I will lift the 6 Injector Mosfets and make some measurements.
I'm just not clever enough to work on cars, I didn't sign up to this degree of complexity
Hi STC try w644b which are 250V N-Channel MOSFET google that for data sheet
and it is indeed a Precision resistor/SMD 0.05Ohm 3W ±1%
its worth getting a component tester Peak make a realy good one about £70 tells you which connection is which and id s the component or there is quite a good cheep one about £10 from china but works well just comes as a pcb no case but works well Ive had my peak tester for about 15 years so its now well out of date
I did in fact Google W664B and got some results. What is confusing me is the fact that they are using different components (I refer to NH43AK & NH44AV Markings) to do exactly the same job i.e. Fire an Injector.
I'm working on the theory / assumption that they have used different components for a good reason - I just don't know the reason. Or am I wrong ??
In an ideal world I would love for someone to spoon feed / guide me / send me a link so I can purchase the correct components.
I wonder if checking / replacing any of the MOSFET driver transistors is going to help? Had it just been one injector not firing then you would suspect one MOSFET had failed. As none of them are firing it is unlikely that they all suddenly failed unless something else is wrong as well - massive voltage overload etc. Such a problem may mean they will all go pop again.
Seems more likely that something before the MOSFETs has failed - one or more components so that the switching signal to the MOSFETs is not happening?
Alan
I agree that something other than the 2 Mosfets must have failed. The Resistor for one has popped and will be replaced. I'm hoping that resistor did the job of a fuse and prevented further damage.
This car has been sat in a corner for at least 8 months and a few people have looked at it. I was initially told that the ECU has been tested and it is fine ?? All the relevant wires have stab marks in them - Powerprobe ?? so who knows if they did press the magic button ....
I have spoken to all the usual Culprits (ecu repairers) and that is all they will do, none of them are able to unlock the immobiliser on the bench to test it afterwards
Further upstream may be an Injector Driver / ASIC that I will look into.
My instinct is that it may have a faulty Injector that is the real cause here. Will do some research and testing.
These components are so cheap to buy that it really is worth my while to experiment. If it doesn't work I will be about £20 out of pocket and wasted just an hour or 2, On the other hand if it does fire up then Kerching !! and another string to my bow.
KIM
thank you for that link, I have seen it and it is the source of the idea to look at and test the Mosfets. The difference being that they don't have the added drama of the blown resistor.
In my experience with electrical components I look at the family and data sheet for said component and pick one from the family with same or higher spec if the original has failed go for a higher spec I dont think the number you are concerned about are the part number for the transistor i would guess that they will be batch numbers or factory ids
a data sheet will tell you a lot
scope the gate of the transistor to see if you have a driver signal I think its about .45volts to open a FET