This is not for my car; it's for the Lexus loaner (ES300) I've had for the last 10 days while my car is at the dealership for a warranty repair. Anyway, I've found that this fuel gauge is defective in that the needle hardly moves up whenever I fill up the tank. Another weird thing is that the low fuel light shows up when the needle is not even below the 1/4 mark!

Does anyone know what's causing this inaccurate reading of the fuel gauge? Maybe a capacitor from the circuit board is blown out? If this info helps, the loaner I've been given is actually a pre-owned car off the Lexus dealership lot, which I assume must have been sitting there for a long time w/out being driven (the tire pressures were really low so I had to air them back in).

 

I've see some of this problem on the 03-04 ES with inaccurate reading and we have to run some test of the sending unit and the guage itself. I think Lexus still working on this problem to narrow it down about the source of the problem. Some car we have to replaced fuel sending unit and some car we have to replaced fuel gauge.

 

Hello,
I have this same problem with my car. The needle on my 99 GS4 reads too fast. When I fill up, the needle starts coming off the full mark at about 40 miles, even if I am on the freeway cruising at normal speeds. I also notice that it seems to slow down after it reaches the 1/2 way point.

Still, the low fuel light comes on at 1/4 tank. When I fill it at 1/4 tank, it takes 13 gallons to fill it back up. On a 19.8 gallon fuel tank, this is most bizarre. My first GS4 did not have this problem.

I called the dealership to make an appointment for diagnosis, and the service writer informed me that there are TWO senders in the tank...one up front, and one out back, and the best estimate of fuel level is done by the computer, which "averages" the levels between the front and back, and sends that signal to the guage.

He also informed me that it might require replacement of BOTH senders....which are 110.00 minimum each, plus the labor associated with it. I asked if there is an ongoing investigation, and he replied that there was some concern early on in theproduction year, but there has been no follow-up due to lack of a considerable number of complaints.

I took that to mean that nothing is being done, and once the warranty expires, it is the responsibility of the owner.

I am living with it right now, but may tackle the problem after the first of the year.