JB4tech.com - International Turbo Tuning Discussion
cls10378 cls10378 is offline
New Member
Posts: 1
Join Date: Aug 2021
Car: 2018 Genesis G80 3.3T
Default JB4 killed fuse junction box? - 08-11-2021, 08:54 AM

I have an '18 G80 3.3T and I have been running a JB4 running V20 firmware, Map 2, for about a year or so. I upgraded to V24_T1 a few weeks ago and was happy with how the car has been running. Well, I had my car parked at the airport for a few days and came back to so much wrong with the car. Short list:

- No headlights, no turn signals, no power steering, no power trunk, half the buttons on the steering wheel didn't work, no ECS, EPB light was on, couldn't get an outdoor temp reading, the Tach and temp gauges no longer worked, no cruise control, check engine light was on and, lastly, the doors would auto lock when the car was off even if I was in the car.

Here is what the dealership stated, as I removed the JB4, as I have a 10/150k extended warranty and I'm just at around 47k miles:

Verified customer concern. Scanned for codes and found could not communicate with any modules. Checked voltages on c-can lines and found 0 volts. Disconnected battery and measured resistance of can lines. Found 61 ohms, which is in-spec. Reconnected battery and found the can lines to be working and was able to communicate with all modules. Scanned for codes and found c161287m c1206, c1643, c1209, c162b, c1651, c181287, c1611, c1812, c1501, b1730, b1329, c180b00, c180a00, c1659, c1667, c1673, c166b00, c2426, c1669, c2427, c1675, u0146, u0126, c1812, c1611, c181787, c181287, b122087, b130487, b130887, b130287, b130587, b163981, b220081, b220181, b195303, c181200. Determined smart junction box has internal failure. Replaced and cleared codes and issues are resolved.

This is what was replaced, and it sits right behind where I plug the JB4 into the ECU:


Anyone heard of this? I am hesitant to plug it back in or at least if I do, roll back to V20 firmware. I was without my car for a week since the part came from Korea, so just want to know if anyone has had this issue or if I need to be concerned.
Reply With Quote
Steve @ BMS/Fuel-It!'s Avatar
Steve @ BMS/Fuel-It! Steve @ BMS/Fuel-It! is offline
Posts: 21,116
Join Date: Oct 2012
Car: 135i
Default 08-11-2021, 10:20 AM

I haven't heard of anything like that, I highly doubt its related.

Click on our banner to visit our website!
Video of our Stage 2 LPFP upgrade installation.

BMS products labeled for use only in competition racing vehicles may only be used on competition racing vehicles operated exclusively on a closed course in conjunction with a sanctioned racing event, in accordance with all federal and state laws, and may never be operated on public roads/highways.
Reply With Quote

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

vBulletin Skin developed by: vBStyles.com
Copyright 2007 - 2022, JB4tech.com