[harkes]

To all current owners of a JB4!

The JB4 installation manual has been updated with the following warning:

"Also be very careful when working with the BMS USB cable as it sits close to the battery rail which is a live +12v connection. Allowing the USB cable to touch the +12v connection WILL damage the JB4 and MAY damage the TMAP sensor wiring requiring the ground bypass at the bottom of the guide to be performed. Wrapping a piece of cloth tape over the battery rail connection and/or USB connection will help prevent accidental damage"

[Earthmaster]

Yep, I read that clear as day thats why I never have USB cord connected while I'm not using it. This pretty common knowledge as its pretty clear in the instructions....

[rustyminded]

Is this for N20 as well ?!!

[Mike@N54Tuning.com]

The N20 the tuner box is located on the opposite side of the engine so accidentally touching the battery rail isn't a concern there. You should still disconnect the battery when working with the wiring though.

Mike

[Mike@N54Tuning.com]

Originally Posted by Earthmaster

Yep, I read that clear as day thats why I never have USB cord connected while I'm not using it. This pretty common knowledge as its pretty clear in the instructions....

It's at the top of the F30 335 install guide for a reason but a little reminder never hurts.

Mike

[rustyminded]

Originally Posted by Mike@N54Tuning.com

The N20 the tuner box is located on the opposite side of the engine so accidentally touching the battery rail isn't a concern there. You should still disconnect the battery when working with the wiring though.

Mike

even posi tape one connected to auto. transmission for read/delete errors ?!

[harkes]

rustyminded
Route your USB cable inside the cabin or disconnect the battery every time you move it around to be safe. If you store the USB cable under the hood then do it in an insulated bag and secure it safely.

Since this warning was not mentioned in the installation manual back in July 2014; I was not aware that a USB cable getting in contact with 12v can cause damage to the ECU. Maybe I am stupid, unlucky or just dont have common 101 knowledge on electronics - no matter the reason I accidentally damaged my ECU. Luckily it can be bettered by small means.

[rustyminded]

Originally Posted by harkes

rustyminded
Route your USB cable inside the cabin or disconnect the battery every time you move it around to be safe. If you store the USB cable under the hood then do it in an insulated bag and secure it safely.

Since this warning was not mentioned in the installation manual back in July 2014; I was not aware that a USB cable getting in contact with 12v can cause damage to the ECU. Maybe I am stupid, unlucky or just dont have common 101 knowledge on electronics - no matter the reason I accidentally damaged my ECU. Luckily it can be bettered by small means.

I have it routed inside cabin from door as jb4 sits to right cowl. but i did something similarly stupid. the canbus wires were cut when i was installing jb4 then i connected battery and it gave me " transmission error" i worked on it for temp. fix while battery disconnected. while driving to shop i didn't have any errors but checked on jb4 it read "121001 tmap sensor short circuit to b+" but it was deleted

them at shop while man was welding he said no need to disconnect battery so i bought him for that as it's 5 min. job after fixing it read "119002 rail pressure sensor short to ground" i deleted or and it never came back
then today i read your post and i was shiting my pants from fear
Jon told me as long as error gets deleted in fine but I'm still worried Is there a way to find everything is ok ?

[franko9217]

I feel dumb, i can't say that i know exactly where the "battery rail" is