ESS TS2 OBC Fuel Correction

[lkstaack]

I doubt that the ESS TS2 is able to provide a modified fuel injection pulse signal to the OBC so that it could accurately calculate MPG, but I thought that I would ask. Anyone know? I'ld e-mail ESS, but I suspect that others would want to know as well.

The reason I want an OBC that functions properly is the reason I want an ESS TS; keep the vehicle looking and operating like stock.

[TxZHP04]

I'd be interested in this as well. I think I've been told that some models can have the OBC recalibrated to be more accurate but I'm not sure of the procedure or which cars this applies to.

[djc986]

I'm interested as well. My MPG calculation seems to be off by ~ 7mpg.

[Safar]

Same here. My OBC is consistently off by 30%... would be nice to have it corrected.

[bluejeansonfire]

My TT kit is usually within 5% or less margin of error from perfection. NickG FTMFW!!!!1!!1!

[Asbjorn@ESS]

The OBC can be recalibrated using INPA quite easily. We typically do it on local installations. There is also a way of adjusting it directly through the instrument cluster menu.

[NickG@TechniqueTuning]

The OBC can be recalibrated using INPA quite easily. We typically do it on local installations. There is also a way of adjusting it directly through the instrument cluster menu.

FYI Asbjorn, it can also be done within the MS43 and MS45 ECUs (and our software takes advantage of that :pimpin: ).

[djc986]

How can it be calibrated through the instrument cluster? Can you provide details/instructions?

Thanks

[paraklas]

My fuel consumption is crap already, no need to have the OBC verify it for me :ben:

on a side note, my cluster is off by 2-3mpg

[mikem7709]

Can mine be done this way as well ? When I fill up it thinks my range is over 500 miles, even at the track yesterday, it was saying 32 mpg. :rofl:

[Asbjorn@ESS]

FYI Asbjorn, it can also be done within the MS43 and MS45 ECUs (and our software takes advantage of that :pimpin: ).

I am fully aware of the scaling function within the MS43 and MS45, I even wrote a few R&D files calibrated for a few members on here, but beta customers complained about minor issues and we scrapped it since it can easily be configured in the cluster as well. I did not want to waste more R&D time on it at the time as new projects were waiting. There is something weird happening with MS45 especially that affects fuel control under part load when scaled more than 10-15%. On newer cars like the E92 M3 this function works perfect and is incorporated in our SC software.

[HighBoostin330]

The OBC can be recalibrated using INPA quite easily. We typically do it on local installations. There is also a way of adjusting it directly through the instrument cluster menu.

How easily? Interested in this. :)

[NickG@TechniqueTuning]

I am fully aware of the scaling function within the MS43 and MS45, I even wrote a few R&D files calibrated for a few members on here, but beta customers complained about minor issues and we scrapped it since it can easily be configured in the cluster as well. I did not want to waste more R&D time on it at the time as new projects were waiting. There is something weird happening with MS45 especially that affects fuel control under part load when scaled more than 10-15%. On newer cars like the E92 M3 this function works perfect and is incorporated in our SC software.

That's very strange that you're getting that kind of behavior. I've been able to rescale the fuel consumption output appropriately without any ill effects (I think on the order of 50-55%....basically the ratio of new injector size to original injector size).

Now that I think of it though, in MS45, you actually don't need to change the OBC consumption factor at all in the DME. With MS45, the consumption factor output is independent of the injector size. The consumption factor is derived from the mass fuel flow variable, before it becomes converted to injection time. Thus, if your mass air flow variable and target AFR values are correct (which both determine mass fuel flow), your consumption factor will automatically be correct (thus, no rescaling necessary).

[Asbjorn@ESS]

That's very strange that you're getting that kind of behavior. I've been able to rescale the fuel consumption output appropriately without any ill effects (I think on the order of 50-55%....basically the ratio of new injector size to original injector size).

Now that I think of it though, in MS45, you actually don't need to change the OBC consumption factor at all in the DME. With MS45, the consumption factor output is independent of the injector size. The consumption factor is derived from the mass fuel flow variable, before it becomes converted to injection time. Thus, if your mass air flow variable and target AFR values are correct (which both determine mass fuel flow), your consumption factor will automatically be correct (thus, no rescaling necessary).

In MS45 you should in theory set TI_SCAL_1 and TI_SCAL_2 to the correct injector size to get OBC to work properly. The problem I have found by doing it this way is that you get weird fuelling bugs during light load cruising that can not be tuned away. These bugs are not present in newer systems and only relate to MS45 as far as I have seen. It is not very noticeable, but since I also made a perfectly working tune with fuel injector difference not adjusted only with that function, but also in part by the basic fuel calculations, I have kept with that.

If total injection scaling works for you in MS45, then very good!

[hoveringuy]

Guys, I've been correcting this problem for over a year now. If you can't recalibrate your OBC directly, see me.

www.seattlecircuit.com

[Dirtboy]

There is also a way of adjusting it directly through the instrument cluster menu.

Please explain. I am interested too.

[Lemonsqr]

The OBC can be recalibrated using INPA quite easily. We typically do it on local installations. There is also a way of adjusting it directly through the instrument cluster menu.

+11111 please do tell...wait, is this the "fix" where you have to do it every time the car is turned off and then on?

[mcr_driver]

More info on instrument cluster fix please stop leaving us in the dark...

[hoveringuy]

Here's my solution.

www.seattlecircuit.com

[HighBoostin330]

Here's my solution.

www.seattlecircuit.com

As AJ said, there is an easier way of just using software to fixed it than using hardware and cutting wires in your engine. Thank you for your suggestion.

[hoveringuy]

As AJ said, there is an easier way of just using software to fixed it than using hardware and cutting wires in your engine. Thank you for your suggestion.


Who has adjusted it through the instrument cluster?

[HighBoostin330]

Who has adjusted it through the instrument cluster?

I would give it a shot. However, my car isn't here right now.

For those that would like to try it, I found this from Google search. Seems like you need to use Test 19 to unlock the tests, then enter into Test 20 and then change the correction factor.

http://forums.bimmerforums.com/forum/archive/index.php/t-61718.html

From what I understand, it is correction factor based. So, X.XX (One . Tenths Hundredths). Similar to that of a dyno.

So go fill up your gas tanks at the gas station. Reset the OBC's MPG readout on the instrument cluster and the odometer mileage. Drive around the way you usually do until you have consumed about 50-75% of your gas tank. Go back to the gas station and refill your gas tank. Then it is a two step process.

1) Read out what the OBC says the MPG is.
2) Manually calculate what your MPG from the odometer mileage divide by the amount of gas you put in your car.

You will find that the MPG you calculate will be lower than what the OBC says. I am assuming that the correction factor is percentage based.

Correction Factor = 1 - [(OBC Readout - Calculated MPG)/Calculated MPG]

Can anyone confirm this hypothesis? My car isn't with me at the current moment. Thanks.

[hoveringuy]

Looking through the WDS the OBC doesn't have a discrete fuel consumption signal wire, it is computed by the cluster directly from data off the CAN bus.

If that is the case, the ONLY way to correct would be through software.

CAN is 1/2 the reason I converted my M54 to OBD1.

[HighBoostin330]

Looking through the WDS the OBC doesn't have a discrete fuel consumption signal wire, it is computed by the cluster directly from data off the CAN bus.

If that is the case, the ONLY way to correct would be through software.

CAN is 1/2 the reason I converted my M54 to OBD1.

The correction factor is in the instrument cluster, not the OBC. So using what you said, I am trying to change how the instrument cluster calculates the data off the CAN bus to display to the driver. What am I missing here?

In any case, I'll try this when I get my car back. Although I do have INPA to try it with if this doesn't work.

Have fun with your OBDI. :)

[paraklas]

I would give it a shot. However, my car isn't here right now.

For those that would like to try it, I found this from Google search. Seems like you need to use Test 19 to unlock the tests, then enter into Test 20 and then change the correction factor.

http://forums.bimmerforums.com/forum/archive/index.php/t-61718.html

From what I understand, it is correction factor based. So, X.XX (One . Tenths Hundredths). Similar to that of a dyno.

So go fill up your gas tanks at the gas station. Reset the OBC's MPG readout on the instrument cluster and the odometer mileage. Drive around the way you usually do until you have consumed about 50-75% of your gas tank. Go back to the gas station and refill your gas tank. Then it is a two step process.

1) Read out what the OBC says the MPG is.
2) Manually calculate what your MPG from the odometer mileage divide by the amount of gas you put in your car.

You will find that the MPG you calculate will be lower than what the OBC says. I am assuming that the correction factor is percentage based.

Correction Factor = 1 - [(OBC Readout - Calculated MPG)/Calculated MPG]

Can anyone confirm this hypothesis? My car isn't with me at the current moment. Thanks.

I will give it a try..

470km = 55 Liters of RON 98 gas

100km distance comes to 11.70 Liters (Real measurements)

My OBC shows: 9.7 L/100

Therefore my correction factor should be 1 - [(9.7-11.7)/11.7] = 1.17 :craig:

Done in US friendly units:
1 liters = 0.264172052 US gallons
Therefore: 11.70L = 3 US Gallons / 62.5 miles
Comes to 20.8mpg average (aggressive driving + ac always on)

[NickG@TechniqueTuning]

The correction factor is in the instrument cluster, not the OBC.

The OBC is part of the instrument cluster on the E46 :)

[Lemonsqr]

I will give it a try..

470km = 55 Liters of RON 98 gas

100km distance comes to 11.70 Liters (Real measurements)

My OBC shows: 9.7 L/100

Therefore my correction factor should be 1 - [(9.7-11.7)/11.7] = 1.17 :craig:

Done in US friendly units:
1 liters = 0.264172052 US gallons
Therefore: 11.70L = 3 US Gallons / 62.5 miles
Comes to 20.8mpg average (aggressive driving + ac always on)
Please report back to see how accurate this method is. I wonder if the correction factor is based on driving style....????

[HighBoostin330]

I will give it a try..

470km = 55 Liters of RON 98 gas

100km distance comes to 11.70 Liters (Real measurements)

My OBC shows: 9.7 L/100

Therefore my correction factor should be 1 - [(9.7-11.7)/11.7] = 1.17 :craig:

Done in US friendly units:
1 liters = 0.264172052 US gallons
Therefore: 11.70L = 3 US Gallons / 62.5 miles
Comes to 20.8mpg average (aggressive driving + ac always on)

Having a correction factor of 1.17 would increase your gas mileage wouldn't it? That wouldn't make sense unless your car is more efficient now with the TS. :rofl:

The OBC is part of the instrument cluster on the E46 :)

Well that confuses things a little bit. hoverguy says calculation is done in the instrument cluster and not the OBC. However, the OBC is inside the instrument cluster. So how does the data get to the driver? OBC->Instrument Cluster->Driver?

[HighBoostin330]

I will give it a try..

470km = 55 Liters of RON 98 gas

100km distance comes to 11.70 Liters (Real measurements)

My OBC shows: 9.7 L/100

Therefore my correction factor should be 1 - [(9.7-11.7)/11.7] = 1.17 :craig:

Done in US friendly units:
1 liters = 0.264172052 US gallons
Therefore: 11.70L = 3 US Gallons / 62.5 miles
Comes to 20.8mpg average (aggressive driving + ac always on)

Okay, I'm not familiar with the metric system of gas consumption, but isn't 9L/100km equal to 26.13MPG. So if you calculated 20.8MPG, then isn't that a correction factor of 0.74?

[Maestroxl]

I think fuel consumpton is calculated in litres per 100 km and then converted to miles per gallon.
So in order to get the miles per gallon down, the litres per 100 km have to go up.

[paraklas]

I think fuel consumpton is calculated in litres per 100 km and then converted to miles per gallon.
So in order to get the miles per gallon down, the litres per 100 km have to go up.

Correct

[HighBoostin330]

Correct

I think fuel consumpton is calculated in litres per 100 km and then converted to miles per gallon.
So in order to get the miles per gallon down, the litres per 100 km have to go up.

Okay, I guess that makes sense then. Let me know if it works then! :)