Fuel level

[Cormacs]

Im having a problem with dashcommand. The fuel level works great all of the time except... After I fill my truck from empty it takes for ever to update. It will increase by something like 1% a minute. Sometimes it takes upto three days to get up to the proper level. Once it hits the proper level it decreases as the fuel is used accurately. It is only after fill up. If I goto data logger it reads properly. It's funny though the number on the left in the data logger is correct for the amount of fuel, but there is three numbers on the right for the fuel level pid the top one says 0% the middle is 100% and the bottom one I noticed reads the incorrect value that reads in the dash board. What's going on here?

[Luis Fernando]

Dash Command does not indicate the fuel level of my 2008 Nissan Sentra 2.0s. However, the dash display indicates the level and kms to go, so the information is available. Do anybody know how to get the information available to DC?
Thanks for any help!

[Cormacs]

Ok from what I understand, dash command averages the fuel level percent and uses that for the display. Well that doesn't make sense because if it was sitting almost empty for a few kilometers and then you fill it the average wont be accurate. going from near 0% to %100 will read %50 until it sits at %100 long enough to adjust the average. Is there anyway to reset this averaging? The averaging would work good for slow changes like the amount of fuel the truck uses.

[Weston@PPE]

Cormacs,

The extra data you see on the right is the minimum, maximum, and average values for the PID. DashCommand does keep track of an average value for every PID, but the current (not averaged) value should be shown on the dashboards. Which dashboard are you using?

Fernado,

Unfortunately, not all vehicles report fuel level. If your vehicle doesn't report it, there isn't really a way to get DashCommand to display it.

[Cormacs]

My truck does display the fuel level PID. The problem is within the tuxedo skin, the fuel level displays the averaged amount. Therefore after a fuel fill up it takes days before that average meets the actual value. Since it displays the averaged number the fuel level is always off after a fill up and in turn the range is off because it basis it off of that averaged number.

[Luis Fernando]

Weston, the calculator display on the dashboard DOES display it, as well as km to empty. So, I presume, the information is available. With a diferent identification, will it be?

[Weston@PPE]

Great! It sounds like it should all be working for you then. As long as you fill in your fuel tank size in the Vehicle Manager, you should get distance to empty as well.

[Luis Fernando]

Westo, probably I didn't express myself correctly. My car has a Nissan onboard computer on the dashboard. It indicates fuel level as well as km to go. However, DashCommand does not indicate these values. Once the information is available to the onboard computer, it should also be available to DashCommand. Is it possible that an identification problem occurs with these signals (different identification that CD does not recognize)?

[Luis Fernando]

For your informatio, the car DOES send the signal to the engine control module!

P0462 NISSAN Description
The fuel level sensor is mounted in the fuel level sensor unit. The sensor detects a fuel level in the fuel tank and transmits a signal to the Engine Control Module (ECM). The fuel level sensor consists of two parts, one is mechanical float and the other side is variable resistor. The fuel level sensor output voltage changes depending on the movement of the fuel mechanical float.


Read more: http://engine-codes.com/p0462_nissan.html#ixzz1sadEG3JN

[Weston@PPE]

The ECU might be have the fuel level information, but Nissan chose not to support the OBD-II standardized PID for SAE.FLI. What information the ECU itself has doesn't matter, all that matters is what information it will give us.

You're not alone on this. I haven't owned a car yet that does support SAE.FLI, but every single one of them reported it using manufacturer specific PIDs with ScanXL and the GM/Ford add-ons. Its a similar situation, my 1999 Camaro ECU knows the fuel level, but doesn't support SAE.FLI. It uses non-standardized, GM-specific PIDs to get this data to a scantool (which also has to be a GM-specific scantool -- NO generic scantool can get this data since its not standardized and will be different for every vehicle).

[Luis Fernando]

Weston, thanks for the information. So, there ares two solutions, both on the config screen:
1) User can input the PID for the fuel level and air temp, as these seem to be the two PIDs thar frequently are reported with manufacturer codes.
2) Once the user reports a fillup, the system assumes full tank (capacity is regularly input on config) and from this point on, DC calculates fuel level based on fuel flow. A short disclaimer warn the user that, if wife drives the car, it won't calculate. But you will make many, many users very happy (like me!).
Both solutions will be easily implemented. Simple calculation for the second, just a different code read fron the config for the first.
Another useful implementation. I use metric system. Fuel consumption is indicated as lt/100 km. Indicating km/lt would much mor useful, staightforward.
Think about. You will get a better app with just a little effort!

[Luis Fernando]

Weston, are those parameters used by DC to get fuel level and ambient air temp for Nissan Sentra?

Fuel Level for ISO & VPW vehicles
GAUGE   TXD   RXF   RXD   MTH   NAME   Notes
Fuel Level   686AF1012F   0441052F0000   2808   006400FF0000   FLV   Percent

Ambient Air Temperature for ISO & VPW vehicles
GAUGE   TXD   RXF   RXD   MTH   NAME   Notes
Ambient Air Temperature (C)   686AF10146   044105460000   2808   000100010000   CTC   Degrees Celsius

[Luis Fernando]

Another possibilty

Fuel Level for ISO & VPW vehicles
GAUGE   TXD   RXF   RXD   MTH   NAME   Notes
Fuel Level   C233F1012F   0441052F0000   2808   006400FF0000   FLV   Percent

Data from http://www.scangauge.com/support/xgauges-for-kwp-vehicles-2/

It would be wise to check there an include possibilities for different formats os troublesome PIDS on the configuration screen.

[Luis Fernando]

I expected at least a short answer!

[John@PPE]

The data you gave us is all standardized PIDs. We're using this same data and your vehicle says the PID is not supported. Everything listed in that link is OBD-II standardized PIDs that our software is already checking.