all-trac fuel level sensor - Toyota Nation Forum : Toyota Car and Truck Forums

aaronhoy · 11-15-2010, 03:32 PM

I'm having trouble finding info on this. I gather from searching around that the fuel level sensor on the normal FWD Camry is integrated with the pump, but the one on our all-trac is separate. The gauge was always reading all the way low, so I popped the sensor out and messed with it a little bit. When I deflect the float all the way up, the gauge reads full, but if I put it anywhere else, it reads empty. Since I can't find any info on the signal between the sesnor and the dash, I'm not sure if the problem is the sensor or the gauge itself. Does anyone know what this signal should look like?

white90dx · 11-15-2010, 08:52 PM

Quote:

Originally Posted by aaronhoy

I'm having trouble finding info on this. I gather from searching around that the fuel level sensor on the normal FWD Camry is integrated with the pump, but the one on our all-trac is separate. The gauge was always reading all the way low, so I popped the sensor out and messed with it a little bit. When I deflect the float all the way up, the gauge reads full, but if I put it anywhere else, it reads empty. Since I can't find any info on the signal between the sesnor and the dash, I'm not sure if the problem is the sensor or the gauge itself. Does anyone know what this signal should look like?

The fuel level sender should be just a variable resistor that changes value witht the position of the float. Does the low fuel warning light still work (it is on separate wires)?

What you should be looking for is variable resistance between 3ohm (fuel full) and 110ohm (fuel empty). I bet there is a crack internally in the fuel level sender and it is 'open' when the fuel level is below full. I'm not sure if it will be repairable or if you will have to replace.

-Charlie

aaronhoy · 11-16-2010, 10:54 AM

Thanks for the info. Yesterday I called the dealer and they wanted like $150 or so for the thing, so I decided to take the old one apart first. When I got it open it was, as you said, just a variable resistor. It was quite simple in fact, just a coil of wire with a piece of metal that drags across it. There were no cracks, but it was just making bad contact, so I took some 1600 grit sandpaper and electrical contact cleaner to it and the sensor seems to be working now. Glad I didn't buy the overpriced replacement...