Outer Limits 4x4 Board

Ok

Subject----Subtank not registering

Truck------Gu patrol

. As stated above the subtank button does not work. When engaged it does not fill up the main tank. A orange light down the bottom of the dash reads in oragne "Subtank". It has been taken to an auto place and there not to sure unless they get the diagram of the nissan wiring, they said their is no power going to the pump to allow the fuel to be pumped from the sub tank to the main. Does anyone know whats wrong.....who can fix this...

Cheers!!

Did it used to work and now doesnt?

If so try disconecting the battery for a fe minutes and then reconecting.

Sounds stupid but fathers did the same in his GU and a mate told me to try this as had run into it on a few gu's, did it and now works perfectly again and hasnt stuffed up since.

Sounded too easy too be true but worked.

If subtank is run dry it will do that.When filling up make sure to fill up sub tank as well.

the subtank pump will only run if there is enough fuel in the subtank (to prevent burning the pump out by running it dry) and the main tank is below a certain level (half full I think).

If the orange subtank light is lit on the dash this would indicate that the subtank is empty therefore the pump will not run. Either fill the subtank or if it is full there may be a dodgy sender making it think its empty.

Clogged. Pull the tank pickup out and give it a good clean.

RoldIT wrote:Clogged. Pull the tank pickup out and give it a good clean.

theres no power going to the pump at all

True, but my understanding is there is a sensor in the sender that decides whether or not the there is fuel to pump and enough room in the main to pump it (pressure sensor and/or float of some sort). If that has failed or is "clogged" it has flagged the warning and until it gets attention, it not gunna send power back to the transfer pump.

I am no expert but this is my understanding of how it works.

The thing is the subtank is full!!, I not sure what can be wrong, something in the lines???

Did ya try disconecting battery yet?

TAZZ wrote:Did ya try disconecting battery yet?

Valid point. Quick, easy place to start.

thepatroldude wrote:The thing is the subtank is full!!, I not sure what can be wrong, something in the lines???

thepatroldude wrote:The thing is the subtank is full!!, I not sure what can be wrong, something in the lines???

you could have a small child wedged in the lines and it wouldnt be the cause of your problem!

its gonna be an electrical fault if you're not getting power to the pump.
what is the orange light on the dash for? is it a low fuel level indicator or is it to tell you that fuel is (supposedly) being transferred to the main tank?

I assume you have checked all fuses and tried disconnecting the battery for a few mins?

doing the battery thing tomoz, hopefull some sunny weather. Will check it then, if not working I will reply back on the forum.

Thanks for urs help so far

Cheers!

Had the same problem with Dad's (Troll00) it has a fuse in the engine bay and the pump gets dirt in it, check and test all the fuses and then turn it on if you get under the car and in front of the tank you'll see the pump if you can't feel it ticking, it's working if not give it a hit with a spanner to dislodge the dirt/sand and fit a filter just before it and you shouldn't have any problems.

ok any updates on this as mine just started doing the same over the weekend, , fitted a new stereo, uhf and boost gauge, all was fine, fitted a turbo timer yesterday arvo now the light stays on on the dash and both tanks are full, will go and try the battery thing too or could it be some thing to do with the timer,

its a 4 wire high energy diesel timer, i hooked it up just behind the key barrell as it said

the timer has a red(12v constant),black(earth), blue(accessories diesel only) and yellow wire(ignition)

the 12v and earths no worries, the yellow wire i hooked to a blue wire in the key loom which was ign pwr and the blue wire to a black with white strip which was acc pwr, does this sound right to you guys??

any help would be great

cheers

i fixed it, disconnected the battery while i had a smoke, hooked it back up hit the key qand the light goes out, yeah!!!!

um its now un-fixed, just went for a drive and the light is back on and staying on, any other ideas other than disconnecting the battery???

I disconnected the battery and the orange light indicating "subtank" no longer appears. When u press the subtank button you can hear a noise which indcates its working. However it does not pump fuel into the main tank as of yet, does it need to be at a certain level in order to operate (main tank) that is.

Cheers

thepatroldude wrote:I disconnected the battery and the orange light indicating "subtank" no longer appears. When u press the subtank button you can hear a noise which indcates its working. However it does not pump fuel into the main tank as of yet, does it need to be at a certain level in order to operate (main tank) that is.

Cheers

subtank has to above empty and main tank has to be below a certain level (probably 1/2 or a 1/4)

Could be a stuffed fuel pump which I recently had.

Look in the main tank filler neck. You should see fuel being pumped into the main tank if the pump is going. (make sure your main tank isn't full)

Apparently there is a small filter in the pump which could get clogged. As mentioned prevously give it a tap or you could try removing it and cleaning it. I tried but mine still didn't work.

I bought another pump, fitted a fuel filter and all works well. Bellows pump which switched off when tank is empty. Cost about $120.00. Genuine was several hundred bucks