73.P3 FAULT CODE - Fuel pump

Hey all.

Need some help on this one... jumped in the ute this morning and fired her up only for her to crank. Wouldnt turn over. Checked everything under the sun and came up with the theory that it was fuel hungry... fuel filter & plunger did feel a bit ordinary so bled lines and tried a few things... cut a long story short I got a bloke to throw a scanner on it and its come up with 73.P3 fault code.

Has anyone else had this one come up? It stands for 'pump communication line' and most of the mechanics I've talked to today have said its 90% pump failure. A few have said it COULD be something else, but most likely pump. Im totally unsure what to do or try. One mechanic did mention that if you hit the key to 'on' and you hear a very faint buzzing noise (not a click like a relay, but a buzz or something) it's the ECU and you will more then likely have power to the pump and it DOES HAVE A BUZZ. So I might be lucky... who knows.

If anyone knows something I could try I'd be happy to try it! I've called around Cairns and the best I can do (if it is pump replacement) is $4K for a recon pump installed. Absolute best anyone can do... I'd love to say its something else but its not looking good!

Cheers in advance

Pump Communication Line. well its not the injector pump it sounds like this PCL code has detected an electrical fault somewhere from the ECU to the Relay etc. find out where the pump relay is and check it plus check any associated Fuses . might need an auto tech to find this fault if you can,t.

Other than disconnecting the plug on the vp44 and checking for corrosion / poor connections there's not much you can do yourself to diagnose for the 0703 code.

Whats the vp44 and where is it located?

Vp44 is the injector pump, front of engine drivers side. I will defer to the likes of rumpig for any details of the pump control though.....

check the earths on the manifold.

check pins on the injection pump connector.
more often than not its the injection pump ecu thats gone.
these injection pumps have there own little ecu built into the top of them. however they are well known to fail due to heat and vibration.

tweak'e said:

check the earths on the manifold.

check pins on the injection pump connector.
more often than not its the injection pump ecu thats gone.
these injection pumps have there own little ecu built into the top of them. however they are well known to fail due to heat and vibration.

Click to expand...

Can the pump ecu be replaced tweake, or does it require a new pump if it dies?

Boogieboots said:

Can the pump ecu be replaced tweake, or does it require a new pump if it dies?

Click to expand...

the ecu can be replaced and the pump reconditioned as the same time.
the pump gets tested and the ecu gets programmed to match the pump.

They don't sell the pump ecu separately they make you buy a complete pump/ecu on an exchange basis. Nice scam.

Manual says 0703 is incorrect voltage reading from the ecm so could be something other than the ecu on the fuel pump.

Rumpig said:

They don't sell the pump ecu separately they make you buy a complete pump/ecu on an exchange basis. Nice scam.

Click to expand...

not really.
pump ecu has to be programmed to the calibration of the pump.
there is no way you can do that at home.
you either do an exchange pump or send your in for reco.

as always check the cheap stuff first.

Thanks guys for the replies. Few things I will check on tomorrow. Heres hoping for good news...

As for recon pump... this doesnt sit well with me at all. The word recon scares the bajeesus out of me. Essentially its a pump which has buggered up, been tinkered with and made to work again. Thats about the guts of it. Its probably the track Im going to have to go down (whats a new one worth + labour?) - has anyone here got a recon pump and whats your thoughts?

Cairns Diesel reckon these modules (the ECU and also the pump) are really only good for 10 to 12yrs... anymore and your doing well.

Will keep you all posted

Solanum1 said:

Thanks guys for the replies. Few things I will check on tomorrow. Heres hoping for good news...

As for recon pump... this doesnt sit well with me at all. The word recon scares the bajeesus out of me. Essentially its a pump which has buggered up, been tinkered with and made to work again. Thats about the guts of it. Its probably the track Im going to have to go down (whats a new one worth + labour?) - has anyone here got a recon pump and whats your thoughts?

Click to expand...

we have one of the d22's with recon pump after it failed. no idea on cost.
afaik they have a standard kit they use to rebuild them. just replace the parts that wear out. its not a case of tinker with it and replace what they think is causing the issue.

Well things arnt going toooo well. Managed to find a thread regarding this same error code on the Patrol forum and certainly tried everything under the sun today... cleaned out vp44 connector, checked every cm of wiring and fuses and earths... but if there's one thing that could save me it might be the fuel filter & primer.

When this issue arose the other day I found it very hard to get the plunger to go hard... I replace the filter every 5 or 10K and know fairly well how long it takes once the filter has been put back together to then prime up hard. However the other day I noticed it took an insane amount of time to get really firm and even then it wasnt as hard as it should have been. Am I right in saying there still might be air trapped in the system? I have tried bleeding the filter & lines but it is proving fruitless. I noticed today the little screw ontop of the plunger wasn't fully wound down and now that it is it's pumping much better... I can get the primer very hard and am confident there's plenty of fuel there, but perhaps still air? I have had an issue in the past where I parked on a hill many years ago at Koombooloomba Dam and still is similar... thought it ticked over after a few minutes (didnt even touch the filter or plunger)

Also... how can the ECU be re-set? Can a possible error code like the 73 be brought about by an air lock and does it need a scanning tool to re-set the ECU to clear the fault? Or can dis-connecting the battery after every attempt to fire up the engine clear the ECU?

(feel as though/praying that the vehicle is displaying an error code that needs clearing as the vehicle is starving for fuel due to an airlock)

Hi Solanum,
I went through similar trouble a while ago, its on this forum under "damned 0707 code."
if you search that it will come up with all the advice I received, and what I tried to fix it.

I'd start off clearing the codes and reading them again when the light comes on.
I can't remember the exact details on how to clear the codes, but i'm pretty sure it's just done by turning the ignition key on and off a certain amount of times. the codes can be read in the same manner. It's all explained in this forum if you search for it.

you may find that the code doesn't come back or a different one comes back.

I was lucky, the fault code finally went away and never came back, I'm still not sure exactly what caused it. I was certain that I was going to have to replace my injector pump, but it eventually sorted itself out and ran fine.
You may or may not be as lucky, but I would definately try to rule out the following things before you bite the bullet on a new pump:

Check for diesel bug, change fuel filter and run fuel treatment.

Check for air leaks in all fuel lines and fittings

check for water in fuel system.

check electrical connections and earth strap.

Good luck

Well to keep you all in the loop...

Car got towed away to diesel service shop in Cairns today... pretty gruesome news. 3 error codes have reared up... rpm sensor, spill valve and the comm line code. The first scan only revealed 1 code however the test may not have been run correctly by the bloke, or he had a very poor scanner.

As you can imagine this is a pretty hefty hit... 4K straight out of the back pocket for a recon pump.

If I could warn zd30 Navara owners this problem is more common then you all think. From the tech's Ive talked to over the phone the last week (and believe me I've done some research on this thing) this is a daily problem with zd30's that are over 10 to 12yrs old. This is irrelevant to how many Km's it has done, it is purely age - this is the main consensus. This is coming from guys that work on these things everyday. Dirty fuel, injection timing and a whole host of other things certainly are a factor but the shear age of the moving parts within the injection pump (as well as the ECM attached to it) is the killer. And this can also happen to any aged vehicle at any time without warning.

Love to know the figures of how many zd30 nav owners this has happened to. Only a fraction of people know about good forums like this... if only they could tell their tales.

I've been a very happy D22 owner since 2013, but as you can imagine this has dropped me like a tonne of bricks. I was brought up in vehicles that had a Tojo badge on the front... back to the good old days.

Again thanks to all info and tricks to try.

A bloke at work was quoted 6g for injector pump on his Pajaro! Turned out to need only a ecu reset. His model apparently has the most expensive out there. I am saving in readiness for my injector pump replacement, I have 270k on the clock now so I know it will be coming at some point, and much less expensive than a new bus

i recall theres been a few common rail setups that cost ~20k to replace.
4k pump doesn't sound to bad.
thats is a problem with 2nd hand diesels. repairing injection issues could well cost more than the ute.

vp44 pumps are known for issues.
heat cycles tend to stuff up the pump ecu. i suspect hotter climates may have more of that, but it also happens in cold climates.

internal wear on the pump is often related to fuel and filter quality. not so much dirty fuel getting through but rather filters blocking up and causing intake restriction. this causes wear on the timing piston which is the main culprit that fails.

probably better to fit two filters in parallel to reduce fuel intake blockage.

we have 3 d22's all of the same age, but different km's. only one has had a pump rebuild and that was probably brought on by fuel blockage.

Hey tweake

4K doesn't sound that bad??? You sound like your good for a loan LOL!!! I spent 3K on a brand new air con the other year for the missus 2007 Mazda 6 (weapon of a car... but Mazda aircons are hopeless and well known for it). That was a big hit but I can handle 3K for a part of the car which isnt running related (plus we live in Cairns, we need cold air). So 4K for a major item of your car (and yes it is fully reconned with new parts like you say) is a big hit and also a worrying one!

To put things into perspective... I know 4 other Navara owners 2 of which are CR2.5 owners. One of my best mates is a zd30 owner and a big reason I brought mine. Of these 4 other Navara's (plus mine to make it 5) 2 have done the injection pumps. Thats 40% - not a good figure at all. Not what you call reliability which is what you want when your cruising around the places I visit.

These VP44's were also in 3Ltr Rodeo's from 2000 to 2006... and we all know how good a car they were. BUT, the pumps were never an issue in them. But, they are certainly a big issue in a 3Ltr Nav and Patrol!

Type "vp44 Failure " into google and you'll be stunned. They were fitted to many makes world wide. It's a Bosch thing, not a Nissan thing.
And I reckon 50% of the pumps that were replaced were probably misdiagnosed, 0707 is quite often air in fuel related.