Fuel Gauge Calibration Instructions

from rick57 over on the old site:

Ok everybody,sorry this has taken to long. Been busy with a lot of things going on and I forgot, Embarassed . I had a new 2G Prius in for PDI and decided to give it a try. And guess what,I found out what we were doing wrong! Just one little step messes up everything. Here is the steps from the TSB and only applies to the 2G.

1. Park the vehicle so as it is level,front to back and side to side.
2. IgOn and make sure that "Trip A " is showing on the odo ( this is where we made a mistake Embarassed ).
3. Power down.
4. Keep your foot off the brake.
5. Push in and hold down the Odo/Trip button.
6. Push the Power button twice to IgOn ( not Ready mode ).
7. Turn the Odo/Trip off then On 3 times in 5 seconds.
8. Continue holding the Odo/Trip button until a 6 digit code appears.
9. Release,then push again the Odo/Trip button for another 5 seconds. The 6 digit code will change to a 5 digit code.
10. After the middle digit,of the 5 digit code,changes to "1" release the Odo/Trip button and the odometer will return to normal reading.

Hope this clarifies the steps.

_________________
Rick Angles
Toyota Master Diagnostic Technician
Toyota Hybrid Technician
Germain Toyota
Columbus, Ohio

 

...and why would one need to do this?

 

if your gas gauge reads really wacky (read: even more wacky than normal.)

the inclinometer is used to set a baseline for how level the car is to interpret the reading of the gauge in the tank into the bars you see on the display.

for example, if you continually run out of gas with 3 bars left, you need this reset. it's not something the average driver should do on a routine basis. they do it at the dealer- this site just happens to have some techs with access to this info...

 

Just out of curiosity would this also make any sort of correction to the opposite condition where I get the blinking single bar and I still have 3 gallons of gas remaining in the tank? According to my dealer he indicates that this is normal!!

 

that IS normal.

if you're not sure, don't do it. it's not meant for the driver to do anyway.

 

did you park the car on an incline when you fueled up? that's what usually does it.

i'd maybe watch it and see how it behaves over the next couple of days- then recalibrate. since you know how much gas you have in there, running the tank dry isn't an issue. how many tanks have you observed on the CanView?

of course that's MHO and not a direct order :lol:

 

ahh, so you're one of THOSE. at least you know the car and you have a pretty good grasp on how it works.

i got in 10... once... after running it so near empty i scared myself. otherwise i'm in the same boat, minus the TSB.

well, a recal can't hurt if you're on a level surface. it would be interesting to compare CanView vs fuel gauge before and after recal- in case the cal was off some at first. well let us know how it goes then.

 

Evan, I finally got around to trying it today and also had no luck. I guess I'll just continue to live dangerously in the 'single blinking bar' world and guess by mileage until one day I guess a little on the wrong side and run out of it!!

 

I performed this procedure on my '05 a couple of weeks ago. It took a few tries, but ultimately I succeeded. The gauge is back to the approximate same degree of accuracy that I used to experience before the car spend a few weeks in the body shop where both batteries were removed prior to the car being placed in the heated paint spray booth.

I will repost Rick's instructions and bold the steps which may be be the key to a successful recalibration:

 

I don't recommed that at all. I also thought I had plenty of gas at the blinking bar because the most I got in during that blinking bar was 10 gallons. Well, after I ran out of gas I still only got 10.6 gallons in. The bladder staying compressed causes the problem. So minus the space taken by the bladder defect your really only have ~10 gallons. Once I fuled with a broken nozzle that I had to shut off after fuel spilled out onto the ground. From the blinking bar I got 11.67 gallons. I was so happy. Now I am back to 9 to 9.5 gallons at the blinking bar. I MIGHT have only .5 to 1 gallon left. That is just a guess. Your guess may vary.

 

It *is* normal, because you don't have three gallons remaining. You have less than one gallon. The tank almost never really holds the nominal amount of 11.9 gallons. If you ignore the flashing bar you will one day run out of gas. Don't say we didn't warn you

 

Still learning my new Prius, so I have a gasoline tank-related question. Has anyone run out of gasoline before the last pip starts blinking? So far in three tanks I have filled up a few miles after seeing 2 pips, and have put in 8.1, 8.6 and 8.8 gallons. Looks like going down to one is reasonably safe?

Thanks

 

Yeah, I'd say yer good there. I just filled up yesterday and put in 9.847 gal. That's the most I've ever put in. I went 442 mi on that tank. The MFD calculated 51 MPG and the manual calc came in just under 45 MPG. The temps have been all over the place and the last time I put gas in it was a lot colder. I don't really trust the fuel gauge at all but I think that on my car it's understating what's left in the tank. That, or my MFD calcs are way optimistic. Considering how variable the temps are here in CO I don't put much faith in the manual calculations. It seems impossible to get a consistent fillup between the bladder, the vapor stuff on the fuel tank, and the particular gas pump you're using. So I've mainly been tracking my fuel efficiency with the MFD. Does anyone know how accurate it is?

 

Ya, I'd like to know too.
On Greenhybrid.com it says I have 38.5, but I was closer to 40 on my lifetime accoring to the computer.

 

What is 'Can-View'??