I've got a 99 525TDS and when i fill the tank the fuel gauge only goes 3/4 full. i've read in previous threads that this could be caused by a faulty sensor on the fuel tank. however if i go into test 2 on the OBC you can run a test that makes the gauges go from zero to fully open but when i run this it still only goes to 3/4 full.so my question is, is it the sensor or is it something else, any ideas?

I've got a 99 525TDS and when i fill the tank the fuel gauge only goes 3/4 full. i've read in previous threads that this could be caused by a faulty sensor on the fuel tank. however if i go into test 2 on the OBC you can run a test that makes the gauges go from zero to fully open but when i run this it still only goes to 3/4 full.so my question is, is it the sensor or is it something else, any ideas?

Bad Cluster? chances are its the gauge itsself, not the sensor.

An angry Irish, eh?
Welcome on board.
There was a recall on this issue back in 1999 or 2000
if my memory serves me correctly. You should call
your local dealership and might get lucky.