Problem with SUBTANK

[Anna]

Hello. I would be grateful if you help me with a problem.
The car has a problem with the subtank. On the control panel from the left side lit yellow with subtank sign and the petrol is not pump from the sub tank to the main tank. How can I fix this defect?
Thank you in advance.

[the evil twin]

Disconnect the battery for 30 minutes.
That will reset the Sub tank computer.
If the fault light doesn't come back on great
If the fault light comes back on then there is a problem with one of the following, switch, computer, sub tank sender, main tank sender, transfer pump or wiring.
There is a way to see the fault code but you may be better off taking it to a service centre to get the code

You can try an 'extra' earth lead from the body to the chassis first tho.

[Anna]

Thanks a lot. I'll try to do so. Hope, it will work properly.

[the evil twin]

Thanks a lot. I'll try to do so. Hope, it will work properly.

I hope disconnecting the Battery works for you.

Do try an extra earth lead from Body to Chassis as well, you can buy them ready made at almost any Auto Parts store.
Remember that if you add an earth lead you still have to disconnect the battery as the last step because even if the fault goes away the Tank Computer will stay latched in the faulty state until the power is removed

If another earth lead doesn't fix this particular problem (which it does maybe 25% of the time) it will still help stop other strange electrical faults developing.

[Anna]

Thank you,
disconnecting the battery works, but after the several time the problem with the sub tank returns. I think the service centre will completly fix the defect.

[Anna]

I turned off the battery, then drove 350 km but there was another problem: the main tank sensor shows full but the tank is not full. So the problem is that I can't undersatand is the tank full or not.
I do not understand what the problem is? Is the sensor broken or there is problem with tank?

[the evil twin]

Given that the Sub Tank Transfer has faulted out as well then I would suspect the Main Tank Sender Unit has a problem.

You or your serviceman can access the Sender Unit fairly easily thru an access panel in the rear floor.

[Anna]

The problem is resolved. The gasoline indicator, on the control panel, was broken. All the problems were caused by this. Now it needs to carry out several actions with adjustment system.
Thanks a lot for your helpful comments and support. :)

[the evil twin]

Good result, enjoy your vehicle hope you have lots of trouble free kilometres

[Anna]

Thank you. :o