So I was out driving and the car suddenly stopped. Fuelpump not working.

When I connect fuelpump direct to battery it works and the car can be driven.

Changed the fuel pump module = not working
Changed the fuelpump = not working
Tried new wires from the ECU to the fuel pump module = not working

All the wiring from pump are tested and ok.

All fuses are ok.

I have both + and - into the fuel pump module, but nothing to the pump.


I´m now running out of ideas what to do!!!

I get 2 codes:
P1338 and B1202

 

JTIS shows an independent earth to pin 6 of the pump module.
Maybe that's bad?
Another possibility is a defective fuel pressure sensor.
On these cars the pump is driven by a PWM signal using feedback from the pressure sensor.
Do you get anything at all on pins 1 + 2 of the pump module ?
If you haven't got access to a 'scope try using the a/c range of the voltmeter.
There doesn't seem to be a DTC for a bad fuel pressure sensor.
Oddly your B1202 is a faulty fuel level sender but I can't believe that would inhibit the pump.

 

If the system thinks the fuel tank is empty it should shut down the pump to avoid burning it out w/o fuel to lubricate the pump.
Check range to empty.

 

Are you sure about that ?
These cars have some fuel left when the gauge reads 0 and you can definitely use it.

 

Interesting!
I have checked the earth to module and it seems fine. I also get read out from the fuel pressure sensor, but if it is the right numbers I honestly don´t know.

I also have readings from 1-2 from the ECM to the fuel pump module. It pulsing between 1-9 volts and that seems ok as far as I know.

 

On a 2003, if your OBDII reader allows real time monitoring you should be able to read fuel pressure in PSI or bar through the OBDII port.

 

Yes no problem. I just don´t know what the correct values are!

 

From memory about 60 psi for an R.
Here's a detailed explanation of how the system works with thanks to Steve (WhiteXKR)
Under Pressure: Maintaining Ford’s Electronic Returnless Fuel System: Underhood Service
Have you got access to a 'scope ?
Is your fuel gauge reading ?

 

Many thanks!
My problem seems to be that the ECU i sending a signal to the FPDM to shut down fuel pump. I have a friend with the same car. I will measure all the sensors/values on his car and see if there is anything that is different between the 2 cars. Wish me luck!

 

Interesting one this.
Try a hard reset (can't hurt)
https://www.jaguarforums.com/forum/x...connect-74146/
Keep us informed - you need a 'scope .

 

Already tried that....
Now I have measured from my friends car. They are identical. Tried swapping fuel pressure sensor also with no luck.

I have come to a dead end. Only thing that remains is to change the ECU (if I can find one....)

 

Have you tried resetting the inertia switch fuel cutoff? (big red button either accessible from the left dash fuesbox or under the dash on the left depending on model year).

 

yes

 

You need to see if the ECM is sending drive signals to the pump module (pins 3+4), if not, are there signals at the ECM (pins 25+27) ?
There's one connector shown in the harness so it or the cables themselves could be bad.

 

Already tried this. Even connected new wiring! ECU is sending between -1 - +7 volts that means "shut down fuel pump" to the fuel pump module.

 

Either the ECM has had a brain fart and is sending the shut down signal itself or, something else is telling it to shut down the fuel pump.

Have you checked the fuel level sender, just in case, as you have that code.

 

I don't understand this - if you refer to the doc I mentioned earlier it is the 'duty cycle' (AKA mark-space ratio) of the square wave the ECM sends the pump module that decides if it shuts down or not.
Without a 'scope to see the square wave you can't tell anything.

 

The P1338 tells me that the voltage to is had fluctuated outside the range required. The B1202 not sure this is correct Fuel Sender Circuit. When I was troubleshooting my fuel indication problem I used resisters to fake it into believing the tank was full. Mine being a 1999 is not the same as your 2003 but I would think you could do the same once you find the two leads for the level indicator that is in your tank. This would eliminate the concern that it is part of the problem. I would also look at the integrity of the battery and its connections.

Link to my 1999 fuel level JagRepair.com - Jaguar Repair Information Resource

If it were the inertia switch it would turn off power to the engine, doors and a mess of other things.

 

Not long ago I had some similar issues with my fuel pump failing, replace two, replaced 4 fuel control units. My mechanic was working down a thread of a fuel temperature monitor which he felt could be sending a shut down signal, if the fuel at the injector rails was too hot. Not sure all the detals, but his shop closed before he was able to completed the job.

In the end the wiring harness between the FCM and the Fuel pump itself had a break, which may have originally been from pulling it through one of the wiring holes in the wall behind the seats.

Hope that helps
mjw

 

I should also mention if your car is a 2003 XKR you have 2 fuel pumps.