DASC and On board computer

[lpcapital]

I'm not sure if the 318ti has an On-board computer that gives and estimated MPG and miles remaining on tank.

If so I was wandering if any of you with the DASC (but not the NickG Stage II) noticed a false reading.

I know that when you run the larger injector provided with the Stage II you need to multiply the MPG reading by 2/3; I was wandering if something similar needs to be done for the plain vanilla DASC setup.

My understanding on how the OBC works is that it gets a signal from the ECU about the pulse rate of the injectors to estimate fuel consumed per unit of time; it then uses the ABS pulse generator to calculate speed and distance. Does some math and regurgitate MPG and miles on tank: is that right?

I was reading how Shawn Fogg was thinking about using the Power Commander to tap into the injectors signal sent from the ECU to the OBC to "correct" the reading: has anyone ever attempted to build a circuit board of some sort to accomplish this?

Thanks

[xxxJohnBoyxxx]

No the MPG readings are good with a stock injector. The DME counts injector pulses and caculates you MPG. I'm interested in building the circuit board but it will not be easy...

Originally Posted by lpcapital

I'm not sure if the 318ti has an On-board computer that gives and estimated MPG and miles remaining on tank.

If so I was wandering if any of you with the DASC (but not the NickG Stage II) noticed a false reading.

I know that when you run the larger injector provided with the Stage II you need to multiply the MPG reading by 2/3; I was wandering if something similar needs to be done for the plain vanilla DASC setup.

My understanding on how the OBC works is that it gets a signal from the ECU about the pulse rate of the injectors to estimate fuel consumed per unit of time; it then uses the ABS pulse generator to calculate speed and distance. Does some math and regurgitate MPG and miles on tank: is that right?

I was reading how Shawn Fogg was thinking about using the Power Commander to tap into the injectors signal sent from the ECU to the OBC to "correct" the reading: has anyone ever attempted to build a circuit board of some sort to accomplish this?

Thanks

[lpcapital]

Originally Posted by xxxJohnBoyxxx

No the MPG readings are good with a stock injector. The DME counts injector pulses and caculates you MPG. I'm interested in building the circuit board but it will not be easy...

If you get it to work under NickG setting, let me know either a DIY or a price cuz I sure am intersted...

It's easy: all you need is something that takes 2/3 of whatever the DME send to the OBC ehehehe!!!

[xxxJohnBoyxxx]

Originally Posted by lpcapital

If you get it to work under NickG setting, let me know either a DIY or a price cuz I sure am intersted...

It's easy: all you need is something that takes 2/3 of whatever the DME send to the OBC ehehehe!!!

A math processing board is easy with a Amtel chip with Hexadecimal code loaded on it. The code part is hard since it will need to tied into the BMW code. I bet Nick could write this in the firmware on the DME but it's a hugh pain in the A$$. I couldn't do it without a disassembly of the DME code which I don't have. I don't even have a OBC that does milage...just outside temp and time

[lpcapital]

Originally Posted by xxxJohnBoyxxx

A math processing board is easy with a Amtel chip with Hexadecimal code loaded on it. The code part is hard since it will need to tied into the BMW code. I bet Nick could write this in the firmware on the DME but it's a hugh pain in the A$$. I couldn't do it without a disassembly of the DME code which I don't have. I don't even have a OBC that does milage...just outside temp and time

That's a good idea to ask Nick!!!! I haven't called him yet since, well, I haven't installed the SC yet.

Meanwhile I'll try to find out how the ECU communicate the injectors pulse to the OBC and I'll get back to you.

Thanks!!!!

[xxxJohnBoyxxx]

Originally Posted by lpcapital

That's a good idea to ask Nick!!!! I haven't called him yet since, well, I haven't installed the SC yet.

Meanwhile I'll try to find out how the ECU communicate the injectors pulse to the OBC and I'll get back to you.

Thanks!!!!

I only know the MPG gauge in the instrument cluster works off of injector pulse & width (A good way to track engine load and fuel used). Have no clue if the OBC uses the same data but it makes sense that it would.

I bet you a beer Nick tells you it's very easy to take 2/3 of the value. His life or any firmware coder's life revolves around math and they assume everyone can do the math in their head as easy as they can. They just don't understand we just want the thing to work as designed by BMW

[lpcapital]

Originally Posted by xxxJohnBoyxxx

They just don't understand we just want the thing to work as designed by BMW

Straight to the point!!!!!

[mohaughn]

The 11 and 18 button OBCs can be reprogrammed through the OBC buttons for fuel consumption. It basically works on a simple formula-

The factor is used to correct the OBC Avg Fuel Consumption figure to reality. If your OBC is off a bit: fill UP totally, run tank down and refill; then calculate your Actual MPG. Now enter test 20 to get the old Correction Factor.
NEW CF= OLD CF *(OBC MPG/Actual MPG)
Enter the NEW CF using the numeric keys and hit SET/RES to store. PLEASE record your OLD CF so that IF you screw up you can always go back to what it was.

I would imagine there is a way to do the same correction factor on a two button OBD. Just have to find the instructions on how to get it into test mode.

[lpcapital]

Originally Posted by mohaughn

The 11 and 18 button OBCs can be reprogrammed through the OBC buttons for fuel consumption. It basically works on a simple formula-



I would imagine there is a way to do the same correction factor on a two button OBD. Just have to find the instructions on how to get it into test mode.

That would be super cool to the max and beyond!!!! I'll look into it... Thanks

[labiel]

My solution to false MPG on my OBC after swap to R6 was to change it for one from 323ti - works perfect Same thing could be with DASC.
ps. as for correction you can do this by pressing 2 buttons simutanlesly and cycling to 3, then s/r and you have correction from 750 to 1250, for me it wasn't enought.