A mod for the die-hard N54 enthusiast who are still around🤙
I posted this mod on a couple of other tech forums and it may be useful for a small number of N54 owners here since no has written this up for JB4 users.
I started working with Burger Motorsport on this in October 2019 and we got Flex Fuel working within a few days. The process is actually very easy and simple. But from the many international Flex Fuel inquiry threads it appears there is still confusion about how the wiring works.
I first tested the full Motive Flex Fuel kit with the Jb4 and it worked out well. But since I had the Fuel-it analyser kit already for many years I decided to use the Fuel-it analyser instead. This thread is about using the JB4 with the Fuel-it Flex Fuel kit with the Motive Flex Fuel (flash) module.
If there are users that bought the Motive Flex Fuel analyser kit then I can do a separate thread on the Motive kit.
1. The Fuel-it Flex Fuel kit I have is the Bluetooth and 0-5 volt analog signal for use with JB4 or an analog gauge. The kit comes with a Flex Fuel sensor, analyser and a cable with 3 wires.
2. I will assume that you already have the Fuel-it Flex Fuel sensor and analyser installed as per the above pictures.
3. Connect the Black wire to Ground. There is a solid ground close to the ECU box.
4. The Red wire goes to the Orange Power wire at the green connector. I used a positap for that connection.
5. Connect the Fuel- it ECA 0-5 volt (white wire) directly to the DME pin #16 of the small black subconnector. My wires are a little dirty because I had to remove some sticky tape from the wires that left some ugly residue. Pin #16 is the DTML or DM-TL signal which should be empty and is used for the ethanol signal. [DTML in USA cars refers to the LPFP - Diagnosis Module Tank Leakage & heating module]
6. Now for the tricky part.
Splice an extra wire into the Fuel-it ECA 0-5 volt (white) wire that is wired into DME pin #16. I soldered mine but you can also use a positap to connect the extra wire. I used a green wire as the extra wire.
See the picture below that shows the two options. Once you have spliced or positap the wire - slot in the extra wire (Green) into pin #2 in the JB4 DB25. This will allow you to read the ethanol content in the JB4 logs/Jb4 app directly from the DME.
7. Purchase the MHD Flex Fuel flash module licence from MHD. This flash module will automatically detect the BMS JB4 Flex Fuel map and apply the blending tables when you flash.
8. Flash the BMS Flex Fuel map - which you must request directly from BMS or your custom tuner. This Flex Fuel map will be pre- FF formatted and calibrated.
* Update to the latest Jb4 firmware.
* Please note that there is a specific BMS Flex Fuel BEF for the Motiv Flex Fuel ECA kit and a specific BMS Flex Fuel BEF for the Fuelit Flex Fuel ECA kit with the appropriate ECA scaling. Make sure you request the correct map from BMS.
9. Activate the appropriate settings in the JB4 Ethanol Setup. Particularly, settings 0 and 1 and 2. See picture below.
10. After flashing check the ECA voltage, ethanol content, fuel interpolation values at (idle) in MHD and then compare with the values in the JB4 app. Ensure the MHD Flex Fuel map values correspond with the map values in the JB4 app (as close as possible).
11. Some things to NOTE:
* I fitted my Flex Fuel kit in 2019 and its been running flawlessly. However, since then BMS adjusted CANbus and opened up an additional analog input which can be used for WMI, PI and Flex Fuel or for additional sensor inputs such as exhaust back pressure or EGT. Please communicate with BMS directly on these additional analog options if you used pin #16 and pin # 2 for something else.
* I ran both ECA kits in my testing and was happy with both but I settled with the Fuel - it ECA kit because the fitment was simpler and straightforward and because it compliments all my other Fuel-it mods.
12. The biggest advantage of going true Flex Fuel is:
* Fully implemented Flex fuel solution running on the stock DME.
* Never having to reflash when running or changing ethanol blends or having to worry about mixing the correct blend. Use straight pump fuel or e85 on the same flash.
* No need to re-flash BEFs when running pump fuel or e85.
* The MHD Flex Fuel flash module automatically adjust the BMS Flex tuning directly and seamlessly.
I hope you find this quick & dirty guide useful.
I posted this mod on a couple of other tech forums and it may be useful for a small number of N54 owners here since no has written this up for JB4 users.
I started working with Burger Motorsport on this in October 2019 and we got Flex Fuel working within a few days. The process is actually very easy and simple. But from the many international Flex Fuel inquiry threads it appears there is still confusion about how the wiring works.
I first tested the full Motive Flex Fuel kit with the Jb4 and it worked out well. But since I had the Fuel-it analyser kit already for many years I decided to use the Fuel-it analyser instead. This thread is about using the JB4 with the Fuel-it Flex Fuel kit with the Motive Flex Fuel (flash) module.
If there are users that bought the Motive Flex Fuel analyser kit then I can do a separate thread on the Motive kit.
1. The Fuel-it Flex Fuel kit I have is the Bluetooth and 0-5 volt analog signal for use with JB4 or an analog gauge. The kit comes with a Flex Fuel sensor, analyser and a cable with 3 wires.
2. I will assume that you already have the Fuel-it Flex Fuel sensor and analyser installed as per the above pictures.
3. Connect the Black wire to Ground. There is a solid ground close to the ECU box.
4. The Red wire goes to the Orange Power wire at the green connector. I used a positap for that connection.
5. Connect the Fuel- it ECA 0-5 volt (white wire) directly to the DME pin #16 of the small black subconnector. My wires are a little dirty because I had to remove some sticky tape from the wires that left some ugly residue. Pin #16 is the DTML or DM-TL signal which should be empty and is used for the ethanol signal. [DTML in USA cars refers to the LPFP - Diagnosis Module Tank Leakage & heating module]
6. Now for the tricky part.
Splice an extra wire into the Fuel-it ECA 0-5 volt (white) wire that is wired into DME pin #16. I soldered mine but you can also use a positap to connect the extra wire. I used a green wire as the extra wire.
See the picture below that shows the two options. Once you have spliced or positap the wire - slot in the extra wire (Green) into pin #2 in the JB4 DB25. This will allow you to read the ethanol content in the JB4 logs/Jb4 app directly from the DME.
7. Purchase the MHD Flex Fuel flash module licence from MHD. This flash module will automatically detect the BMS JB4 Flex Fuel map and apply the blending tables when you flash.
8. Flash the BMS Flex Fuel map - which you must request directly from BMS or your custom tuner. This Flex Fuel map will be pre- FF formatted and calibrated.
* Update to the latest Jb4 firmware.
* Please note that there is a specific BMS Flex Fuel BEF for the Motiv Flex Fuel ECA kit and a specific BMS Flex Fuel BEF for the Fuelit Flex Fuel ECA kit with the appropriate ECA scaling. Make sure you request the correct map from BMS.
9. Activate the appropriate settings in the JB4 Ethanol Setup. Particularly, settings 0 and 1 and 2. See picture below.
10. After flashing check the ECA voltage, ethanol content, fuel interpolation values at (idle) in MHD and then compare with the values in the JB4 app. Ensure the MHD Flex Fuel map values correspond with the map values in the JB4 app (as close as possible).
11. Some things to NOTE:
* I fitted my Flex Fuel kit in 2019 and its been running flawlessly. However, since then BMS adjusted CANbus and opened up an additional analog input which can be used for WMI, PI and Flex Fuel or for additional sensor inputs such as exhaust back pressure or EGT. Please communicate with BMS directly on these additional analog options if you used pin #16 and pin # 2 for something else.
* I ran both ECA kits in my testing and was happy with both but I settled with the Fuel - it ECA kit because the fitment was simpler and straightforward and because it compliments all my other Fuel-it mods.
12. The biggest advantage of going true Flex Fuel is:
* Fully implemented Flex fuel solution running on the stock DME.
* Never having to reflash when running or changing ethanol blends or having to worry about mixing the correct blend. Use straight pump fuel or e85 on the same flash.
* No need to re-flash BEFs when running pump fuel or e85.
* The MHD Flex Fuel flash module automatically adjust the BMS Flex tuning directly and seamlessly.
I hope you find this quick & dirty guide useful.
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