I bought a 2016 4runner sr5 last week, I love her but the fuel gauge is not working properly. Im guessing fuel sending unit, does anyone know if the sending unit is part of the fuel pump or is it separate?

So I reset my ECU by leaving the negative battery terminal disconnected overnight. My digital Range display jumped up by 50 miles, I stopped at the gas station and topped off. It sent the Range to 437 miles, the last fill up only resulted in the range showing 377 miles. Now to see if the gauge moves, it seemed to be stuck on full but I will watch, if my range gets down around 310 the needle should show 3/4 a tank. Hope this works, not looking forward to removing the tank.

I've had my 2018 SR5 for about 6 months. The most my fuel range has displayed was 380 after filling up. Did you purchase from a dealer? If so I would take it in to get checked out. Is your 4runner passed the 3yr/36k miles?

Hope you get this sorted without having to spend any money.

OH yes I just bought the 2016 with 75k on it. Its like new, very nice condition. So far so good with the reset. If it does not work I will install a new sending unit myself.

What is your exact problem? My 2011 Trail have been running out of gas even when it says it still has 1/4 tank or 50 miles. I've disconnected my battery for 30 minutes and reconnected. I haven't ran out since then because I haven't let my tank get that low again. Will update if it happens again.

The gas gauge seemed like it was stuck on full. The first time I filled it the range meter said 380 miles like the other guy that posted on here. I'm thinking hmm with a 23 gallon tank that would be a mpg of 16.5 my mpg runs between 18 and 19. After resetting the ECU the range meter jumped up 50 miles. This time when I filled up it showed 430 miles on the range meter, which is closer to 19 mpg. So now I will watch the gas gauge vs range meter and see if they are in sync. I only drive about 15 miles per day so this may take a week or so.

I'll admit to being confused about your symptoms. Are you saying that the fuel gauge indicates full always AND that the digital range decreases down to a reasonable value like 100 after driving an expected distance??

If distance remaining decreases at a logical rate as you consume fuel then the sending unit must not be the problem since the distance remaining is a calculated value derived from the amount of fuel the sending is indicating.

For the original question: the sending unit is part of the fuel pump ASSEMBLY. But is not part of the fuel pump- the sending unit is a distinct replaceable part of the assembly.

The Techstream program has a module that allows simulation testing of the gauge. Also, you can get enough access to move the float to test for specified ohms without dropping the tank. There is an access panel under the rear seat.

Attached Images

 

What I was trying to convey is the fuel gauge needle did not match up with the amount of gas in the tank nor did it match up with the range displayed on screen. But.... since I reset the ECU everything is working properly now. I was thinking out of the gate I might have a sending unit issue but after I reset the ECU, the range display now says 433 miles with a full tank. I let it go until the range read 310 miles and now the needle is at 3/4 tank which is where it should be. Before the needle would stay at full until below a half tank and a full up only showed 370 miles on the range display. I would appear the reset has solved my problem.

I also verified the amount of gas with a fill up. I was missing exactly 1/4 tank.

If actually get to the low fuel light, mine triggers with 4 gallons left in the tank, takes 19 gallons to fill it. I have a 2015 and 2018 4runner and both are the same with the low fuel light.

Mine is a 2016 and has a 23 gallon tank. That is why I did not understand at a fill up why the range was only showing 370 miles. 370 / 23 is only 16 mpg. But after the ECU reset now shows 433 which is 18.82 MPG which is closer to what Ive been showing as my mpg.

I haven't let it go to the low fuel light yet but with the gauge working properly now i'm confident it will work like it is supposed too.

Both mine have a 23 gallon tank. Mine, 2018, only gets about 17mpg. I am heavy footed. Hers, 2015 Limited, is better and closer to 18 to 19. She is an easy driver and it has 22k miles. Mine hasn't broken 3k miles yet.

Yeah, we don't drive much.