Russelsfl

Forgive me if this has been answered, Ive read the install guide and watched the videos on bms site, searched the forums etc, and its not clear how to log into the jb4 to change the map.
I see how to install the jb4, but when I want to run the program to change the map, do I leave the jb4 installed and connect my laptop to the obd2 or do I remove the jb4 and connect it directly to my laptop?

Thanks!

Flash5

You need to turn on the car or at least hit the start button to have it in “on” where all the electronics are on. Then connect your laptop to it and adjust your settings.

Russelsfl

Thanks! My question though is do I leave the jb4 installed in the engine bay and connect to the obd2 port?
I read something about having to run a cable through the firewall and in the video it looks like I am supposed to connect directly to the jb4. But in the video he's using the bluetooth kit not the hardwire.

Russelsfl

I was looking at some pics of the jb4 installed and I think I figured it out.
The jb4 remains installed with the input and outputs connected in the engine bay and the obd2 cable is connected to the other end of the jb4 and connected to the laptop, I could run the cable through the firewall for permanent install and for data logging while I drive, or I could just hook up my laptop to the jb4, change to map2 and then remove the cable.
Am I correct?

Flash5

The way you are describing this is a little confusing haha. So you don't have the bluetooth sensor right? So basically the OBD2 cable hooks up from the tuner to the OBD2 port inside the car under the steering wheel. The tuner is also hooked up to the ports that actually control your turbo etc. That leaves the USB cable as the only free cable. That cable if you don't run it into the car (I'm not sure you can without an extension) then you can pretty much only log and change your settings when your car is parked and you hook up by opening the hood. If you do run the USB cable into the car then you would be able to stay hooked up to your laptop for however long you want as well as log while the car is moving haha.

Mohaamadq

Hey Guys!

i just received my jb4 kit and was attempting the install, but I am also wondering about something similar.

Is the OBD2 connection from the tuner box to the interior needed to enable the JB4? I followed the instructions on the bms site and it doesn’t speak to the OBD2 cable it came with at all. I’m terribly new to all this sorry if it’s been answered before I just can’t find it anywhere for the Lexus i200T

Flash5

Yes, the OBD2 cable needs to be plugged into the OBD2 port and then routed into the engine bay and connected to the harness of the tuner box itself.

BMGS

iTrader: (1)

It does not need to be plugged in, however you will be limited to Map 1 (+4psi) and obviously the logging and code reading features.

Mohaamadq

That makes sense! Thank you both for the quick replies!

I currently have the BMS intake installed while everything else is stock. Do you guys recommend a certain map for that setup? I’ll be getting the invidia Q300h axleback and midpipe setup soon as well.

Thanks in advance!

Mohaamadq

hey I was also wondering how you guys ran the obd2 cable? I see the two grommets for passenger and driver side. Driver side being closer to the obd2 port. What method did you guys use running the cable from engine bay > interior?

Flash5

The BMS instructions should tell you exactly how, but in a nutshell you have to get like a flathead screwdriver to move the grommet enough to run the cable through and into the engine bay. There’s no way you can route it through the passenger side I don’t see how unless they started providing a way longer cable haha. I would have preferred to run it all the way to the passenger side but the cable they provided me was nowhere near long enough.

BMGS

iTrader: (1)

I am fairly new to this engine but not to modding. Based on what I have gathered so far, the turbo is expectedly small so Map 1 (+4psi) is the best place to start. Most seem to end up at Map 2 (+5psi). You won't get much more performance after that as the engine output is limited by the turbo size and intercooler.

You can push extra psi but you will be out of the efficiency range. Water injection can be something helpful to cool down the intake the charge and otherwise increase that efficiency at the same psi. I will try that once my warranty is up.

I am happy with map 1 and I am in a heavier GS. Now that I finally got the OBD II cable hooked up, I tried Map2 but haven't noticed a difference as of yet.

BMGS

iTrader: (1)

I requested a longer cable and they sent it to me. At least on the GS, when my JB4 was mounted on the passenger side, it didnt make it's way to the driver's side grommet. I made the argument that the box should be on the cooler intake side rather then near the exhaust and turbo side.

In the driver's side footwell there is a grommet and on that grommet there was a spare spot to run a wire. You can see it around 1 o'clock on the photo below. I poke a skewer through there and you can then find the extra inlet nipple on the engine bay side. You then cut the nipple end and spray silicone lube into the nipple to get it nice and slick. Then on the inside, tape up the connector and jam it into the grommet. I then used a 1/4" ratchet extension to push it all the way through into the engine bay
it was tight but I got it through. Keep in mind this was on a GS but maybe it's similar on the IS.

Flash5

Hmmm, I don’t remember seeing an extra hole in the grommet itself on my IS, BUT I didn’t look that hard for a hole in the grommet haha.

BMGS

iTrader: (1)

Yeah the easiest way is to push the side of the entire grommet out of the way with a flathead but that places the wire in between the outer edge of the grommet and the metal edge, defeating the entire point of the grommet. I did this first but then after pulling out the wire, I already saw abrasion against the wire. I then was going to place a small tube or sheath around that wire (essentially another grommet) but I found that extra hole in the OEM grommet and went for it.