Why the top fuel level bar lasts so long

[tk-421]

@CTScott: Is there a way to measure (in a more precise manner) how much fuel is left in the tank by using an OBD module?

[CTScott]

Originally Posted by tk-421

@CTScott: Is there a way to measure (in a more precise manner) how much fuel is left in the tank by using an OBD module?

Not really. There isn't an OBD command for fuel level. If we knew the secret Toyota handshake, I could poll the cluster for the fuel level, but that would be the same latent data that the fuel gauge shows.

The problem with doing it by fuel flow is that it is one way. Unless you could also read the flow rate into the tank, you'd still be working down from an approximation.

[CTScott]

Originally Posted by PK198105

why would you need a two way? if we would be able to read the fuel flow, then each time you would fuel up you would input the amount into the ucontroller and then just use the fuel flow to calculate the instantaneous fuel level. you could program the ucontroller to always take under consideration whatever is left in the tank and then add this amount to the amount you put in at the gas station. not sure if i'm explaining it clearly

I know what you mean. Actually, the fuel flow rate is calculated from the MAF flow rate (there's not a standard PID for fuel flow), so even that is an approximation.