JB4 Thread for Lotus Emira AMG i4 (M139 Engine) – Tuning, Setup, Results & Support

[Milk242]

Help!!
I’ve just installed a JB4 to my 2.0 (360 HP) Emira, but have had issues with limp mode and CEL notifications.
On first test run, Map 0 seemed fine, revs no problem, no limp mode. Changed Maps, limp mode kicked in around 3k to 4K revs. Backing off and then slowly depressing the accelerator, the revs rose and the limp mode faded away, but no significant increase in power. Floor the accelerator, and limp mode returned revs increased but no significant boost in torque. The fault codes read mostly PO237 turbo charger Boost sensor circuit ‘low’.
I then re-checked installation including all connections, particularly the cursed MAP connection; went to the extreme of even checking each wire for continuity of current.
For the next test run, I disconnected the OEM MAP plug at the “pig tail brown wire” connection point, leaving solely just the direct to JB4 MAP plug in place at the MAP sensor, with the thought that having both MAP plugs connected may cause a conflict.
After clearing the CEL fault the road test seemed fine, revs, no problem, no limp mode encountered. Turned the engine off (to refill with fuel). Turned the ignition on, and hey presto, back came the CEL again. I continued the road test (ignoring the glaring CEL) using all MAP choices no limp mode present, but noticeable lack of power (commensurate with the PO237 fault code).
Has any member having installed the JB4 to their 360 HP engine experienced the same problems?
I’m just wondering, while awaiting a reply from Terry Burger, whether the JB4 was developed/configured based on a 360 hp engine or the 400 hp unit as supplied to USA imported Emira’s.
Your thoughts and ideas for a solution are most welcome, before I unbolt the entire modual and feed it to the rubbish bin.

I was getting boost sensor errors and my jb4 was also hooked up via obd2 but getting no readings. Using the latest beta firmware fixed the issue for me after I reported the issue to Terry and he quickly found the culprit in his firmware code.

 

[Nelumbo nucifera]

Thank you very much for the pictures. These are very helpful!



I got mine in January 2026 and it looks exactly like that. The box with the cables and two extensions.



Did you get any feedback from them? Mine is a 360hp version as well. I was planning to install it on Monday but I'm not sure if I want to go through the whole ordeal twice

Has anyone else experienced problems with JB4 and the 2.0 i4 360 HP version?

Thanks!

Burger are excellent at providing responses. Aside from what is posted on the forum, contact is being made both ways by email. I have no qualms at all, about having my problem sorted.
As noted by Rayjoedef (see his post above) he experienced similar problems. His and my testing has identified a glitch in the JB4 module (box), which in both our cases simply requires swapping out the present module (leaving all wiring etc in place) and installing a replacement (which I have requested).
Electronics in any car can sometimes bring a fault……….. occasionally. Only two of us have experienced this with the Emira 2.0 engine JB4.
Plenty of others have it installed in both the V6 and AMG 4 like ours.
Burger tuning are confident with their product, in giving a 5 year warranty. The car makers from whom you and we bought our car, show their confidence by providing a 3 year warranty woohoo. I’m sticking with Burger.
Can we rest assured Terry Burger will take care of minor hiccups, like mine? Absolutely! He reads these posts, don’t you Terry, along with many prospective JB4 purchasers.
Put yours in my friend.
Regards,
Richard.

 

[Nelumbo nucifera]

Burger are excellent at providing responses. Aside from what is posted on the forum, contact is being made both ways by email. I have no qualms at all, about having my problem sorted.
As noted by Rayjoedef (see his post above) he experienced similar problems. His and my testing has identified a glitch in the JB4 module (box), which in both our cases simply requires swapping out the present module (leaving all wiring etc in place) and installing a replacement (which I have requested).
Electronics in any car can sometimes bring a fault……….. occasionally. Only two of us have experienced this with the Emira 2.0 engine JB4.
Plenty of others have it installed in both the V6 and AMG 4 like ours.
Burger tuning are confident with their product, in giving a 5 year warranty. The car makers from whom you and we bought our car, show their confidence by providing a 3 year warranty woohoo. I’m sticking with Burger.
Can we rest assured Terry Burger will take care of minor hiccups, like mine? Absolutely! He reads these posts, don’t you Terry, along with many prospective JB4 purchasers.
Put yours in my friend.
Regards,
Richard.

Something to consider. I wanted a cool place to mount the JB4 module, as the engine compartment gets very warm. Some mount it on the ECU. I found a cool-cool easy to get at place under the parcel tray besides the incoming cool air vent as pictured.
Though next time (which is coming) I shall use a piece of angle aluminium and bolt it to the shelf (for want of a better term) using nylock nuts.
It does not get extreme heat from the engine in that place, I can confirm. All the best.

 

[Lun]

So, I ended up having some time today and got to installing it. Moving the AC Compressor was definitely the way to go. (thank you everyone for the tip)

After a bit of cursing and some bruised knuckles I got everything into place while triple checking every connection and the car starts up, I can connect to the JB4 but I got an immediate check engine light. I'm also reading 0 boost and I'm pretty sure it is not generating any because you don't even hear it.

Any ideas?

I'll reach out to Burger and hope for an easy fix (cause I don't really feel like taking it out again ..)

 

[Nelumbo nucifera]

So, I ended up having some time today and got to installing it. Moving the AC Compressor was definitely the way to go. (thank you everyone for the tip)

After a bit of cursing and some bruised knuckles I got everything into place while triple checking every connection and the car starts up, I can connect to the JB4 but I got an immediate check engine light. I'm also reading 0 boost and I'm pretty sure it is not generating any because you don't even hear it.

Any ideas?

I'll reach out to Burger and hope for an easy fix (cause I don't really feel like taking it out again ..)

Well done with the connection/installation side of things.
You will find Terry Burger very responsive to any concerns or glitches, which is very reassuring.
Do you have or can you get, an OBD fault (CEL) read out which should identify what the fault is?
Not 100% needed by Terry, I’m sure, as he will want to view logs from the JB4; accessed and sent by means of your phone app.
All the best.

 

[Lun]

Well done with the connection/installation side of things.
You will find Terry Burger very responsive to any concerns or glitches, which is very reassuring.
Do you have or can you get, an OBD fault (CEL) read out which should identify what the fault is?
Not 100% needed by Terry, I’m sure, as he will want to view logs from the JB4; accessed and sent by means of your phone app.
All the best.

Can confirm, they have been super responsive. We're still troubleshooting the situation, so I'll report back when it is (hopefully) fixed.

I managed to get the reading of the code, 289 I think but I didn't manage to take a screenshot. Now I'm currently unable to read the codes through the app.

We'll see how far we get today.

 

[Milk242]

Can confirm, they have been super responsive. We're still troubleshooting the situation, so I'll report back when it is (hopefully) fixed.

I managed to get the reading of the code, 289 I think but I didn't manage to take a screenshot. Now I'm currently unable to read the codes through the app.

We'll see how far we get today.

If you are unable to read the code through the jb4 pro app, it almost seems like the same issue with mine. Did you try the latest stable firmware?

 

[Nelumbo nucifera]

If you are unable to read the code through the jb4 pro app, it almost seems like the same issue with mine. Did you try the latest stable firmware?

Pardon my entry back into the thread. But just what is “the latest stable firmware” as I too are unable to fault read off the JB4 app?

 

[Milk242]

Pardon my entry back into the thread. But just what is “the latest stable firmware” as I too are unable to fault read off the JB4 app?

JB4

JB4

dev.jb4connectkit.com

 

[Nelumbo nucifera]

JB4

JB4

dev.jb4connectkit.com

Thank you so much. Now all I have to do is sort out what it all means and how to download it/add it to my phone app.
AMG/Mercedes Geely included knew how to mess us around when they de-tuned and locked the ECU. But determination and switched on Techs, should overcome their ploy…….. we would hope.

 

[Nelumbo nucifera]

It'll be worth it....car rips, especially in colder climates

Thanks for your postings. May I ask, is your AMG Engine the 360 Hp model or the 400 HP unit that ended up in USA and I believe China?

Did you have issues immediately following installation of the JB4? If so what was the main problem and how was it resolved? Are there any on going problems you are having centred around the JB4 itself?
Thank you so much for any light you can share on this subject.
Regards,
Richard

 

[Rayjoedef]

Hi Richard - US 400hp variant. The JB4 failed 2 months into ownership - Payam over at Burger thought the board looked as to have been crushed. Not sure how that would've happened unless the manufacturing process on my particular unit was subpar. Terry didn't hesitate and sent me new board. Car runs strong since the reinstall. I also have the GFB blow-off valve - not sure if it's placebo at this point but the throttle has become more sensitive, something I really enjoy.

 

[Lun]

If you are unable to read the code through the jb4 pro app, it almost seems like the same issue with mine. Did you try the latest stable firmware?

I believe so. I went through the app, "Download" and then selected the latest stable version. Unfortunately, the Bluetooth connection was still very inconsistent for me but I might be hitting other issues (still being looked at).

What I can say to the people following this thread and thinking of installing it yourself is, go for it. I couldn't install it following the official documentation (moving the intercooler) but by moving the AC Compressor, it is much easier. Now I'm just hoping that Burger than figure out what is wrong with my unit, so that I can finish the installation on my side

 

[Lotus F1]

I believe so. I went through the app, "Download" and then selected the latest stable version. Unfortunately, the Bluetooth connection was still very inconsistent for me but I might be hitting other issues (still being looked at).

What I can say to the people following this thread and thinking of installing it yourself is, go for it. I couldn't install it following the official documentation (moving the intercooler) but by moving the AC Compressor, it is much easier. Now I'm just hoping that Burger than figure out what is wrong with my unit, so that I can finish the installation on my side I actually had to adressed the installation issue many many months ago I even uploaded the directions that TDI had suggested with all the instructions but like most threads they can get lost

 

[Nelumbo nucifera]

Hi Richard - US 400hp variant. The JB4 failed 2 months into ownership - Payam over at Burger thought the board looked as to have been crushed. Not sure how that would've happened unless the manufacturing process on my particular unit was subpar. Terry didn't hesitate and sent me new board. Car runs strong since the reinstall. I also have the GFB blow-off valve - not sure if it's placebo at this point but the throttle has become more sensitive, something I really enjoy.

Thanks so much for your comments. I’m interested in knowing how many have 360 HP versions with JB4 attached giving grief, and how many 400 hp models with JB4 ATTACHED.
THANKS AGAIN

 

[jamesgareth]

I agree with this. It’s just that being robbed of 40 bhp just because “EU”, really hurts. But yes, no one is forcing me to fill that gap and as I already said (agreed with actually), waiting for the warranty to expire is the way to go for me. I will try to preserve the engine and the car value (…) as much as possible, then who knows. Maybe I’ll find some exhaust mod validated for EU regulations to start with, I don’t know.

Yeah but does it hurt? Come on. You don't sound like the kind of person who uses the first 360bhp let alone needs the last 40. Driving mine around the roads in the UK I pretty much never have the thought 'oh if only I had another 40 bhp'. These yanks are a different breed with their lovely canyon tarmac and their straight roads for miles into the middle of nowhere. Enjoy what you've got my friend would be my humble advice. Let the Americans play with their toys.

 

[jamesgareth]

I
Got that message after installing an Li-ion battery. Garage, and others on here, reckon that a software update will fix it. I’m booked in for the update on Friday, but the message has gone away now!

I find most problems with my i4 are cured by following this simple process.

1) Get out of the car
2) Lock it
3) Go inside your house
4) Make a cup of tea
5) Drink said cup of tea
6) Return to the car.

In 99% of cases any problems with the car will now have been resolved.

 

[virtualmacho]

Yeah but does it hurt? Come on. You don't sound like the kind of person who uses the first 360bhp let alone needs the last 40. Driving mine around the roads in the UK I pretty much never have the thought 'oh if only I had another 40 bhp'.

Errm, I wouldn't judge people just by their posts... He used a good portion of the 400+ in my V6 manual last week on the track, and probably could easily have done 2'02 on his first try on Fuji Speedway in the DCT. I would have loved to see him drive the ECU tuned i4 demo car that a shop brought along !

These yanks are a different breed with their lovely canyon tarmac and their straight roads for miles into the middle of nowhere. Enjoy what you've got my friend would be my humble advice. Let the Americans play with their toys.

Totally agree !

 

[Nelumbo nucifera]

I was getting boost sensor errors and my jb4 was also hooked up via obd2 but getting no readings. Using the latest beta firmware fixed the issue for me after I reported the issue to Terry and he quickly found the culprit in his firmware code.

Greetings. You said in an earlier post that you had an issue with the JB4 installed to your 2.0 T engine. I understand it is resolved. May I ask, is your car the USA imported 400 hp or the 360 hp model?
Thanks in advance.

 

[Milk242]

Greetings. You said in an earlier post that you had an issue with the JB4 installed to your 2.0 T engine. I understand it is resolved. May I ask, is your car the USA imported 400 hp or the 360 hp model?
Thanks in advance.

I live in the US so car is the 400hp version