My sub fuel tank stopped working.. (1 Viewer)

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May 2, 2009
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Location
Cairo, Egypt
I've got a 2006 1FZ-FE 100 series with an OEM sub fuel tank (40 liters).

A couple of days ago I hit the "Sub Tank" button and nothing happened. (For those who don't have this subtank, a yellow indicator next to the fuel guage will light up and the fuel guage will switch to sub tank, and it should start pumping its juice).

I looked for blown fuses, nothing. My fuse block covers do not indicate any fuse for the sub tank circuit.

Is there maybe a relay or some other thing I could check before taking it to a workshop?

Does anybody have the sub tank mentioned in any of the repair manuals? Cause the ones I checked on the net never mention this.

Thanks.
 
Forgot to tell you that a few days back I dismantled the sub tank cause I mistakingly thought a drill hole in the trunk floor will hit it.. turned out it was not so and I put it back up again.

Yes I double checked the plugs and/or wires.. nothing wrong there.

I cannot confirm that the sub tank stopped working after this dismantle, as I havent used it for months..
 
PM me your e-mail address and I will send you what others sent me for an electrical schematic for the aux tank.

Relay? Connection at top of tank to fuel pump? Fuel pump?
 
Maybe the floater inside the tank got stuck in "empty" position while you had it off the car, and this prevents the pump from running? Just a wild guess.
 
Sit in the car in a quiet garage, IGN on, radio and everything else OFF, operate the sub tank switch and see if you hear a solenoid clunk. Lots of earlier problems with the gauge (combinatiion meter) not working but the solenoid changeover still works. The fact that you have had the tank out and now it doesn't work........... this would be my next place to check. Spresso has diagrams of the V8 LHD wiring, not sure if the 1FZ is on it as well, it will be similar though. To pull the tank you probably didn't touch the solenoid wiring, just the sender unit, so my guess would be that that it where you problem lie, do the solenoid operation check though.
 
Sit in the car in a quiet garage, IGN on, radio and everything else OFF, operate the sub tank switch and see if you hear a solenoid clunk. Lots of earlier problems with the gauge (combinatiion meter) not working but the solenoid changeover still works. The fact that you have had the tank out and now it doesn't work........... this would be my next place to check. Spresso has diagrams of the V8 LHD wiring, not sure if the 1FZ is on it as well, it will be similar though. To pull the tank you probably didn't touch the solenoid wiring, just the sender unit, so my guess would be that that it where you problem lie, do the solenoid operation check though.

I will check for the click, but the lamp "Sub" lamp next to the guage isn't turning on either, so I'm guessing there is a cut somewhere in the circuit.

Does it play dead if there is no feedback of fuel in the tank? Or would the lamp light on but no pump action?
 
No clicks.

If the floater has been stuck while laying the tank on its side, and it is sending an empty signal to the ECU.

Will this prevent the switch from giving any signs of life?
 
Solved!

Went to an electrician... he made a hot wire connection somewhere in the fuse box, disconnected the battery for twenty minutes, put it back, and the sub tank worked!

He told me there must have been a short somewhere, the control unit decided to shut off this section, until further reprogramming.

Thanks for those who tried to help.
 
100 Sub tank combination meter and light not working

Lots of earlier problems with the gauge (combinatiion meter) not working but the solenoid changeover still works.

I have exactly this problem - the solinoid changeover works but my fuel gauge still reads the main tank and the SUB light does not come on:confused:

If anyone can point me in the right direction I would be very greatful:clap:
 
I have exactly this problem - the solinoid changeover works but my fuel gauge still reads the main tank and the SUB light does not come on:confused:

If anyone can point me in the right direction I would be very greatful:clap:

If anyone can point me in the right direction I would be very greatful:clap:[/QUOTE]
As mentioned earlier, the problem lies in the combination meter, they replace the entire combination meter (big cost). I believe they also add a wiring harness to the changeover that contains a diode to prevent spikes from the solenoid coming back up the line and blowing the combination meter.
Speak to toyota about it, get them to supply the parts at least, it is a known problem but they haven't initiated a recall. I believe the did issue a TSB and add the wiring harness to a range of vehicles. Toyota don't fix the meters (not that they tell us, they may send them back for remanufacturing) I believe there may be a diode or transistor blown on the circuit board which is the problem, SMD devices though. You could wire in a separate small relay and just switch the sub tank gauge over to the main one so it switches when you push the button. make sure you protect it from spikes from the coil though or you may loose you main tank display as well
 
Thanks for the info - although it is much appreciated it is not what I wanted to hear!!!

It is a pity Toyota did not do a recall... The last thing I need is to loose the main gauge as well? And I am not sure I want to strip the dash to get the guage out? How difficult is this?

This is not looking good particularly as I am sitting in South Africa and it is an Australia spec GXL!
 
The combination is fairly easy to get out and put back, a few screws at the top, lift up the bottom black trim with dash light rheostat and disconnect, IIRC you need to remove the IGN barrel trim and drop that lower cover. At the bottom of the combination meter there are 2 big phillips screws, undo them completely then with your screw driver push them in, this releases the wiring harness from the back of the meter. No need to remove steering wheel, just place a piece of thin cardboard on the steering column cover(lower steering wheel) and slide meter out, cardboard will stop the steering column from being scratched. Mine was replaced under warranty, there have been others out of warranty replaced as well. If you are a member of the LCOOL.org forum, you will see some recent events where someone had it replaced out of warranty. I would try that path first, but if you do no good then either repair the dash or put in a changeover relay with diode protection.
 
Thanks for this info - it has given me some hope that I may be able to tackel this. Your knowledge of how to remove it is invaluable!!

I need to find out if the SA spec VX 100 has the same sub tank and combination gauge setup as the Aussie spec GXL 100. I may then be able to source one locally. Otherwise it will be more complicated!

Is there any chance of getting a second hand combination gauge from a scrapyard dealer in Australia?

Can one test if it is the sender or the gauge that is the problem?

Thanks again for the info - it is really appreciated.
 

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