fbt12
Posts: 46
Joined: Mon Oct 28, 2019 11:34 am

2017 i3 with REx coding warning -- don't mess with gas tank

Okay.....i am probably the only person that try to increase gas tank usage on a 2017 i3 REx....but in case someone else does. Here is my story. Perhaps you will get a laugh out of my stupidity.....please feel free to laugh because i sure feel silly.

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Okay...so i took ownership of a 31k mile CPO 2017 i3 REx on Halloween 2019. Started reading message boards. Joined a few and then i read about CODING. Oh boy...read enough to be dangerous and forgot to read the fine print. As you might imagine, i though my i3 REx was limited to 1.9 gallons of gas usage on a 2.4 gallon tank. Did not immediately learn that in 2017, this limit was removed on US cars. Unfortunately, i learned too late.

So, i bought a OBDLink MX+ OBD2 Bluetooth Scanner & paid for Bimmercode (iOS version) and proceeded to turn on some things. Very cool. Played video through USB (too bad no FF or Rewind controls). Turned on HOLD SOC feature. Set default driving/startup mode to Ecco Pro. Enabled AM radio. Removed startup warning. And, i changed the RANGE EXTENDER > Increase electronically limited fuel capacity from "Unassigned value" to "Active".

I is smart! Right? Wrong! Very wrong.

So, what i actually did was enable electronic limiting. In fact, unlike other settings i could not return it to UNASSIGNED. So for a few weeks, i have been trying to figure out what can i do.

Today, I just figured that i had to restore an old backup (the original) for this particular ECU setting. [Yeah....too dumb to live....why did it take me so long to do a RESTORE??!!!] Before i performed a restore of the original settings, i compared the EXPORT MODE settings for 3005 TANK. When viewing the INSTRUMENT CLUSTER (KOMBI_I01_F56) in Bimmercode, i selected EXPERT MODE on the bottom of the screen to read the settings in 3005 TANK.

There are 3 expert menus that relate to using the gas tank:

1. TNK_LITER_RECHTS
No change from default to changing value of RANGE EXTENDER > Increase electronically limited fuel capacity from "Unassigned value" to "Active".

2. TNK_VOLL_ANZEIGE
This setting went from 8.5 liter to 8 liter.

3. TNK_OHM_RECHTS
mcv_rex_ohm_kl_rects was checked in both before and after.
mcv_rex_ohm_kl_rechts_us_1607 was not checked before but was checked after.


My range for gas changed from 67 miles to 99 miles.

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If you read this far, hope you are smiling and enjoying my anxiety filled lessons on proceeding with caution and more planning!

If you needed to read this, i hope this helps you solve your problem.

Happy New Years!
joni3s
Posts: 56
Joined: Wed Oct 02, 2019 11:16 am
Location: VA

Re: 2017 i3 with REx coding warning -- don't mess with gas tank

fbt12 wrote: Mon Jan 06, 2020 3:23 pm EXPERT MODE on the bottom of the screen to read the settings in 3005 TANK.

There are 3 expert menus that relate to using the gas tank:

1. TNK_LITER_RECHTS
No change from default to changing value of RANGE EXTENDER > Increase electronically limited fuel capacity from "Unassigned value" to "Active".

2. TNK_VOLL_ANZEIGE
This setting went from 8.5 liter to 8 liter.

3. TNK_OHM_RECHTS
mcv_rex_ohm_kl_rects was checked in both before and after.
mcv_rex_ohm_kl_rechts_us_1607 was not checked before but was checked after.


My range for gas changed from 67 miles to 99 miles.

--------------------------

If you read this far, hope you are smiling and enjoying my anxiety filled lessons on proceeding with caution and more planning!

If you needed to read this, i hope this helps you solve your problem.

Happy New Years!,
Just to be clear for others, can you clarify what the values should be for the full use of the tank.

1. TNK_LITER_RECHTS - "Unassigned value"

2. TNK_VOLL_ANZEIGE - 8.5 liter

3. TNK_OHM_RECHTS
mcv_rex_ohm_kl_rects - checked
mcv_rex_ohm_kl_rechts_us_1607 - not checked

is this correct?
2018 I3s rex
fbt12
Posts: 46
Joined: Mon Oct 28, 2019 11:34 am

Re: 2017 i3 with REx coding warning -- don't mess with gas tank

I am hesitant to respond since i quite ignorant of how this all works.

So...let me frame my response.

What i reported at the end of my post was just what Bimmercode showed me after i made the mistake; and then (what i saw) after i restored an older backup (and seemingly restored my 2017 i3 REx back to correct, default setting -----> before i even modified anything. I assume that this setting for the gas tank is in fact default, but i do not know for sure.

I do not know if these settings (in EXPORT MODE) will work for all 2017 i3 REx.
I do not know if these settings (in EXPORT MODE) will work for any other models.

All i can say is that for MY CAR --->

1. I mistakenly tried to add the ability to use the entire gas tank of gas. This is a mistake because 2017 i3 with REx already have this capability stock.

2. After i (mistakenly) modified the settings using the standard Bimmercode, user friendly changes, i used the expert mode to compare 3 settings. I used the following youtube as a (partial) reference --->

https://www.youtube.com/watch?v=lbBu3qHSKFg

I assume that this person in the youtube was modding a 2016 or earlier i3 with REx. I reviewed his display of EXPERT MODE (4:28 mark is the start of EXPERT MODE display).

3. Since i was referencing a video of someone mod'ing a non 2017 or later i3 REx, i have no way of verifying that any of these screens are applicable to anyone's i3. I just wanted to tell my story and my experience with my i3.

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If you have Bimmercode and the correct ODB adapter --- check out the latest list of adapters @ https://bimmercode.app/adapters/ --- AND A 2017 i3 REx, you may see the same readings as i did.

Using the Bimmercode app for me allowed me to use one of the saved backups to reverse my mistake.

Good luck.
Sonickwizat
Posts: 5
Joined: Fri Aug 12, 2022 1:55 pm

Re: 2017 i3 with REx coding warning -- don't mess with gas tank

Okay so I made the same mistake but found out that I can’t restore to the original programming, only had 2 backups and restored the oldest and did not correct the coding I had done. I was able to change the tank size to 8.5L and then I tried to uncheck one of the settings in expert mode but was unable to. So now what can I do to correct this problem?
Protege1
Posts: 1
Joined: Thu Sep 01, 2022 6:20 am

Re: 2017 i3 with REx coding warning -- don't mess with gas tank

Does anyone know if there has been a formal recall of the 2014 BMW i3 REX regarding the pressure sensing switch inside the gas tank which causes the check engine light to appear on the dashboard?

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