Keep throwing P0463 codes on low gas

[l0aded]

So last week I threw a P0463 code (Fuel Level Sensor Circuit High Input) a little after my low gas light turned on. I didn't think much of it as I read on forums it doesn't seem like a big deal. I filled gas and cleared the code and everything was fine. Today, I threw the code again, ALSO a little after my low gas light turned on. Does anyone know what is happening? Is there a problem with the sensor, electrical system or ECU?

Also I am OFT tuned with an aftermarket battery but probably unrelated.


Possibly bad gas? Loose cap? It's strange since my fuel readings are fine.

[l0aded]

Just cleared the code (still low on gas). It hasn't turned on yet. THe intermittent-ness of this is pretty annoying.

[Celadrielas]

At risk of making this over complicated, the OFT could actually assist in this, though the tune itself is possibly unrelated. If are looking at or logging, please let me know what your RPM, Throttle %, FLKC, FBKC, IAM, STFT and LTFT are.

This will tell us if you are having knock, your fuel trims for short term and long term, What throttle percentage, and RPM you're at.


On the other had, usually if you were knocking bad enough, you'd be having other CEL, so it could be the sensor itself.

[l0aded]

Originally Posted by Celadrielas

At risk of making this over complicated, the OFT could actually assist in this, though the tune itself is possibly unrelated. If are looking at or logging, please let me know what your RPM, Throttle %, FLKC, FBKC, IAM, STFT and LTFT are.

This will tell us if you are having knock, your fuel trims for short term and long term, What throttle percentage, and RPM you're at.


On the other had, usually if you were knocking bad enough, you'd be having other CEL, so it could be the sensor itself.

Thanks I'll definitely do that when I get the chance. As far as I know it drives perfectly fine though.

[Celadrielas]

Originally Posted by l0aded

Thanks I'll definitely do that when I get the chance. As far as I know it drives perfectly fine though.

Our engines are fantastic at adjusting to prevent knock. I went through a tune I had (Custom... not OTS) which had an IAM of .97. Basically this means 3% knock never knew until I was monitoring it through my OFT.

I don't know this is causing the issue you're having either. This would just help ensure your engine it's damaging itself. It could honestly be a bad sensor. I did research and found no other people reporting the issue though.

[SteveIsBored]

Originally Posted by l0aded

So last week I threw a P0463 code (Fuel Level Sensor Circuit High Input) a little after my low gas light turned on. I didn't think much of it as I read on forums it doesn't seem like a big deal. I filled gas and cleared the code and everything was fine. Today, I threw the code again, ALSO a little after my low gas light turned on. Does anyone know what is happening? Is there a problem with the sensor, electrical system or ECU?

Also I am OFT tuned with an aftermarket battery but probably unrelated.


Possibly bad gas? Loose cap? It's strange since my fuel readings are fine.

U have a fuel sender circuit issue. This vehicle has a saddled tank, I think so u have two senders the computer uses both to estimate how much fuel u have. If one is bad u could still have a somewhat accurate reading. If u were getting fuel rail pressure codes then I would start to worry about drivability

[dolph]

Did you ever find the cause of this?

I'm having this exact same issue, although I have a stock tune and an almost entirely stock 2013 BRZ Limited auto (save for a K&N drop in filter). The car has never been to the dealer for any reason (no recalls, etc). I had the chirping issue for 3-20k miles or so. Currently at 33k miles.

My car has thrown this code twice. On both occasions, the sequence of events has been as follows:

1. Low fuel light comes on, as expected, during normal driving. Fuel gauge seems steady and accurate. I legitimately need gas.

2. I'll get to my original destination, thinking that I'll get gas afterwords. I'll park the car for over an hour.

3. Car seems to struggle a tiny bit to start, almost like the battery not fully charged.

4. Shortly or immediately after starting the car, the CEL will come on. I'm not sure when it comes on because I might just not be noticing it immediately, due to the other orange lights already on my dashboard (low fuel, etc). Car runs fine, otherwise.

5. I'll stop for fuel, turn the car off, fill the tank, check and clear the CEL. P0463.

6. Again, the car seems to struggle a tiny bit to start, almost like the battery not fully charged.

7. Many driving cycles follow without a Low Fuel light, without any noticeable trouble starting, without any unexpected fuel behavior from the fuel gauge, and without a CEL.

Perhaps coincidentally, this has happened on two consecutive tanks of gas from different gas station brands in different parts of town.

[Faceless]

Originally Posted by dolph

Did you ever find the cause of this?

I'm having this exact same issue, although I have a stock tune and an almost entirely stock 2013 BRZ Limited auto (save for a K&N drop in filter). The car has never been to the dealer for any reason (no recalls, etc). I had the chirping issue for 3-20k miles or so. Currently at 33k miles.

My car has thrown this code twice. On both occasions, the sequence of events has been as follows:

1. Low fuel light comes on, as expected, during normal driving. Fuel gauge seems steady and accurate. I legitimately need gas.

2. I'll get to my original destination, thinking that I'll get gas afterwords. I'll park the car for over an hour.

3. Car seems to struggle a tiny bit to start, almost like the battery not fully charged.

4. Shortly or immediately after starting the car, the CEL will come on. I'm not sure when it comes on because I might just not be noticing it immediately, due to the other orange lights already on my dashboard (low fuel, etc). Car runs fine, otherwise.

5. I'll stop for fuel, turn the car off, fill the tank, check and clear the CEL. P0463.

6. Again, the car seems to struggle a tiny bit to start, almost like the battery not fully charged.

7. Many driving cycles follow without a Low Fuel light, without any noticeable trouble starting, without any unexpected fuel behavior from the fuel gauge, and without a CEL.

Perhaps coincidentally, this has happened on two consecutive tanks of gas from different gas station brands in different parts of town.

Same exact thing here

[Freetime]

Quit letting your gas light come on. Problem solved.

[JazzleSAURUS]

Originally Posted by Freetime

Quit letting your gas light come on. Problem solved.

It doesn't cost you much more to keep the tank full, than it does empty...

[strat61caster]

Originally Posted by Freetime

Quit letting your gas light come on. Problem solved.

Originally Posted by JazzleSAURUS

It doesn't cost you much more to keep the tank full, than it does empty...

This shouldn't be happening, this is not a solution imo.

That's almost like saying "My car won't turn left" and your answer being "Well just make 3 rights".

It doesn't sound like these guys are driving deep into empty territory (I have with no issues, I've filled over 12 gallons twice now and over 11.5 ~20x (13.2 gallon tank) without issue), considering check engine lights can put the car in limp mode (likely to happen with a fueling code) this can cause legitimate problems.

[l0aded]

Just a short update. I have not thrown the code since I first posted back in Feb (I think). The culprit IMO was using Torco Accelerator (concentrated race fuel for octane boosting). Since I stopped using that I have not thrown codes.

Also, back when I was throwing codes there was no effect on the car as far as I could tell. Besides temporarily losing cruise control lol.

[microbionic]

This issue has started to occur on my stock 13 BRZ, for the past 3 tanks. I have since been trying to keep the fuel level higher. but still would like to find a solution. Anybody?

[angadam]

I also had this issue about 6 months ago but it seemed to clear up on its own so I let it go. Other than a single fill up that I put 11.5 gallons in when the tank showed just over 1/4 before I haven't had any issues until yesterday. The check engine light is back on and the gauge seems to be in a different spot every time I start the car. I have an appointment with the local Subaru dealer on Monday and I will post what they find.