Thread: 2011 D4 'Gearbox Fault' warning

Putting the horse slightly before the cart I figure I'll just get a pump. Even if by slim change I don't need it now chances are I'll need it eventually.

This one? (assuming 'In Stock' means in stock)
Genuine Ford SZ Territory/Lion Diesel Fuel Injection Pump


Or is this a roll of the dice:
2.7L Diesel LR017367 High Pressure Fuel Injector P… - Land Rover & Jaguar Parts Manufacturer Wholesaler China

Hi Bananas
You can get a 5% discount at Jefferson by subscribing to their email.

It’s a nice feeling successfully diagnosing and repairing a tricky fault. You earn a moment where you can bask in the glow of your cleverness. I do anyway. And then you go and do something like this…

I pull the trigger on the fuel pump, I watch and read all I can about wrestling the old one out and the new in, I psych myself for grazed knuckles, the 3D puzzle ahead, the dropped bolts, the dwindling daylight with so much still to do and so on. I am at peace and actually looking forward to it.

The disco has had a few days off to think about how it’s behaving. I get home from work with about 30 mins of light left so I figured I’d get the LPFP checks done. First step, check the current draw. I open the door to see that I had left the GAP tool in the OBD port for 3 days. It’s warm and I think, that was dumb, I wonder how much it draws.

I check the LPFP current with the ignition on, but without starting the engine. Just under 8 amps. Off to a good start. I figure I’ll check again with the engine on before moving to the pressure test. Yep. Not enough grunt in the battery to turn it over So I take the battery out of the car since it’s parked on the street so I can charge it inside, have a cup of tea, then head back out to scoop up the tools and lock up for the night (anyone see the problem here)

So with the battery now on charge, an unlocked car on the street (too lazy to reinstall the battery for now) and a fuel pump that has not arrived in time for the weekend (it would have been a miracle if it had - but that is beside the point), I’m left feeling the exact opposite to the wonderful feeling of accomplishment I look forward to! Oh well. At least I know not to leave the GAP tool plugged in and I am reminded not just to rush into things BEFORE a cup of tea.

And yet I’m still looking forward to the job once the pump arrives. I still have the filter to install tomorrow to restore a tiny shred of dignity.

What a muppet!

Originally Posted by Bananas

And yet I’m still looking forward to the job once the pump arrives.

It took me 9 hours over 4 sessions. I had bruised forearms skinned knuckles and put on 3 kilos from the beer I drank. It worked though.

Well...look what we have here. Do I have the smoking gun?

Battery back in, clear all faults (I figure most will be from the flat battery), start logging, pull out from the curb - 'Gearbox Fault' almost immediately:

IMG_4911.jpg

Scan faults - only 1 fault now showing on the GAP:

IMG_4908.jpg

Clear faults, restart: again with the same fault as shown above:

IMG_4912.jpg

I still need to check the LPFP pressure for good measure but these graphs have a striking similarity to those posted by BradC and PerthDiso.

Do I have this right? As the load on the engine increases or more accelerator is applied, naturally more fuel needs to be forced by the HPFP into the fuel rail. The pressure control valve gets the the command to open to increase the fuel pressure. If the fuel pressure does not increase as expected it's likely the PCV is physically stuck and cannot open to force more fuel from the HPFP into the rail. The ECU continues to shout louder at the PCV (which is still looking at it's phone and not listening). The ECU command hits a 50% ish threshold (is this even a thing) and has a tantrum and shuts the show down.

Alternatively, assuming the PCV is behaving there could be a blocked filter etc, but from the balance of others experiences, a sad PCV is more likely.

That’s pretty much it in a nutshell unfortunately. I got temporary relief by using the expensive BP diesel, but it could well just have been coincidence.

Yep the 87 code is very hpfp linked as per the video link.

Have fun. I did about 11 hours but was stuck unbolting the hpfp for about 3. Don’t forget you need a new tensioner and belt as that’s another boondoggle to reuse.













There’s a great description on the job on Disco3. Front bolts on hpfp are tricky you need to work a ratchet spanner on a torqs bit. Very slow all blind by fingertips .

The back bolts fought me with loctite and then seized the spacer inside against the frame which was another hour puzzle to solve.

Hope pics help. Plug everything with caps on the fuel side. Alfoil works well as well as a temporary seal.

Awesome guys. Much appreciated. Glad to have a pretty reliable diagnosis. 1 belt and 1 slab of beer to add to the prep list. Anything else? Bandaids? Coins for the swear jar? I’ll be hitting refresh on the pump tracking number all week and if it arrives in time I’ll devote next weekend to the task.