Fuel pump drawings none starter problem

[mspdan]

hi guys,

i have a V reg 306 HDI bought about two weeks ago know and today it has died. Its been playing up for three days not starting or cutting out and not going again.

Anyway before anyone says try reading the forum i have spent two evening reading and not come across what im looking for so hoping someone can help please.

I have plugged into into diagnostics and got fault code is P0230, yes that dreaded one.

Anyway checked the lift pump and its not priming, so wired it up to a battery and it works. So i then checked for a live on the plug for the pump which is the blue wire or marked p+ on the pump, which is showing no voltage.

So i then went to the engine bay, checked all fuses which are okay. I then checked the inertia switch which has a 12v supply so from this i decided the fuse in the box was okay.

this then lead to the relay behind the ecu, brown one. This had already been rewired and has individual wires to the relay. I have tested connector 8 and found there is 12v going in.

However this is where my problem lies, i then removed wire 4 (for the lift pump) tested the pin for this and its only reading about 3v?

what i would like to know is should this still be reading 12v here as obviously i need 12v at the pump and it drops to about 10v cranking.

I believe i should but would like to double check with someone before i go buy a relay from pug to see if this rectifies the problem.

All help is welcome and i hope this makes sense

thanks

dan

[Eeyore]

youve done what I would suggest so good luck!

[mspdan]

youve done what I would suggest so good luck!

thanks just pondering this voltage at pin 4 i believe it should be 12v but like someone confirm, then if this is the case i will get a new relay

[cully]

i believe if you look at the casing on the pump the 4 terminals are labled
P+ P- * * cant remember the order though
P+ & P- are the pump connection the other two are the sensor wiring check the voltage on these two

[cully]

a common issue is the terminals burning at the relay base

[mspdan]

a common issue is the terminals burning at the relay base

hi there thanks for the information but already ahead on that one, mines already been rewired and there are no plug and no burnt bits, was done about couple years ago.

As to the pump ive already checked the wiring etc as per description above.

Just after the information on the relay voltage at pin four so i can proceed but thinking it should be 12v not the 3 volts showing????

thanks

[cully]

pin 4 is the 12v switched output to the fuel pump
it is internaly linked to pin 5 which feeds the egr and 3rd piston on the hp pump

pin 8 is the other side the relay switch that should be +12v battery

[mspdan]

pin 4 is the 12v switched output to the fuel pump
it is internaly linked to pin 5 which feeds the egr and 3rd piston on the hp pump

pin 8 is the other side the relay switch that should be +12v battery

not to brilliant here mate may sound dumb, so waht your saying is i need 12v at pin 4 on the relay? if i havent the relay is knackered?

thanks

[cully]

im guessing at 99 you have a 1 plug ECU

when you switch the ing on you should get 12v at pins 4 & 5
only for 10-15 seconds then the relay shuts down unless the car starts

you must have 12v on pins 11 & 8 all of the time

[attachment=12248]

[mspdan]

Thanks for that mate, this resolves my question on that one, i have only 3v at pin 4 so relay is obviously knackered then. I have a spare relay i hav enever used so see what reading i get on this one if not i will get a new one from pug when they reopen.

Would that explain why i have no live at the lift pump or would that still be another problem?

thanks

[cully]

if the relay is not supplying 12v the pump wont run

what i would do to test the pump is link pin 8 & 4 then listen for the lift pump or try to start the car

[mspdan]

if the relay is not supplying 12v the pump wont run

what i would do to test the pump is link pin 8 & 4 then listen for the lift pump or try to start the car

so i need a relay then i guess.... i was going to run a live and earth to the pump and see if the car fires up, dont want to bodge it want to resolve the electrical fault, not do the usual wire another live in on a switch...

[welshpug]

central locking still working fine?

[mspdan]

central locking still working fine?

funny you should mention that sometimes of late it hasnt been working properly, u have to unlock it with key thwen it starts working again. This however has only been since its been cold, but i know i could do with a new battery...

[welshpug]

check the CL fuse, if that has blown it will not start.

if you locked with the plip then unlocked with the key the alarm will still be armed too, so if it is playing up its best not to use the plip at all.

[mspdan]

check the CL fuse, if that has blown it will not start.

if you locked with the plip then unlocked with the key the alarm will still be armed too, so if it is playing up its best not to use the plip at all.

the central locking still works though so fuse cant be gone mate... plus there is no live to lift pump and i think the realy is knackered tbh as it only has 3v not 12v at it...

[cully]

bad connection at the CL fuse could give you reduced voltage
this fuse is in the box near the battery under the bonnet

[mspdan]

bad connection at the CL fuse could give you reduced voltage
this fuse is in the box near the battery under the bonnet

ah i see your point but i have checked all engine fuses and contacts when i went through earlier... thinking test other relay and pin 4 and 5 and see what happens, then wire a direct live to lift pump and see if it will start and see what happens..

[C2K]

My suggestion would be as per last sentence, to wire permanent 12v to pump and try to start the car. Then see where we are at if she fires. Ive got loads of the brown relays if thats your problem, there are two part nos, 240107 and 109 iirc.

I'm only down the road in Peterborough.

[mspdan]

My suggestion would be as per last sentence, to wire permanent 12v to pump and try to start the car. Then see where we are at if she fires. Ive got loads of the brown relays if thats your problem, there are two part nos, 240107 and 109 iirc.

I'm only down the road in Peterborough.

C2K thanks for that going to try it know so i know where i stand in the morning and test voltage on other relay that came with it see if i have 12v, how much would you want for a relay mate and when would you be available if that is the case as pug want £16 i know but as to when they reopen i dont know

thanks

[mspdan]

right so bit of an update, have changed the relay and both pin 4 and 5 have 11.5 volts.

I then moved to the fusebox under the dash, as i was told there is some green relays and a 10amp fuse to check.

I started with the green relays and the second one is burnt out, i have to double check this but im sure they had something to do with the fuel system, will have to check wiring diagram unless anyone else can confirm for me?

I dont know if this is the fault or just something i have found in the process

thanks

[cully]

right so bit of an update, have changed the relay and both pin 4 and 5 have 11.5 volts.


thanks

if this has 11.5 at pins 4-5 is the pump running in the tank will the car start ?
if not check you have the same voltage at the P+ & P- wires on the tank pump plug

[mspdan]

Afternoon Cully,

still as previous i have no live at the wires for the lift pump, no voltage what so ever.

Does anyone know after the relay where the next area the wiring is i can check to try and isolate an area that it is loosing the voltage?

I have done a continuity test on the wiring to the lift pump and the live is fine, so im guess i have an earthing problem?

Doesw anyone know how the lift pump wiring runs on the car and where it comes out or earths?

thanks in advance

dan

[cully]

fuse is next in line from the relay

[mspdan]

cheers cully, where am i looking for this, in the fusebox under the steering column?

if you could give me the next few stages to check as i have a mate coming down after ive had dinner give me a hand and to also wire a live and earth to the pump to check the car runs as it was a bit late last night.

thanks buddy

[cully]

autodata says the earthpoint for the fuelpump is on the bulkhead near the throttle pedal

[mspdan]

fuse is next in line from the relay

autodata says the earthpoint for the fuelpump is on the bulkhead near the throttle pedal

cheers again cully will check the earth, as i did have aload of wires there loose and i did tuck them out the way as to not catch them so thought maybe this could be the fault. Where is the next fuse / wiring to check please.

thanks

[mspdan]

right...

bit of an update, i have wired a live off another battery and a neutral to the pump and it turns on and the car will run so that rules out ignition, ecu and immboliser if i am correct?

the earth is connected up fine on the bulkhead behind the throttle pedal, guessing i need to check the reistance on the earth next?

also where does the wiring come into the interior from the engine bay to see if i can see where i am loosing voltage please as im a bit stuck on which section to rule out next...

maybe try another earth to the seatbelt anchor from the pump and see if i then get a live on the pump wiring and it turns on and runs

thanks for any help in advance...

[cully]

check fuse F35 15amp in the engine bay fuse box

[mspdan]

already checked buddy, fuse is not blown and connections to it are all fine...

where from here please, sorry to sound like im going on just trying get source of the problem

thanks