[BayouBimmer]

I brought my car in today to get my new battery programmed and I left my jb4 connected and on map 2. the dealer said that they were unable to communicate with my computer...I was wondering if the jb4 is blocking it and if so can I just put it on map 0 or does it have to be removed? I switched from a lead acid to agm so I have to get it done. thanks in advance

[Sidewinderpb]

It's supposed to be Map 0.

That being said, I've left mine at the dealer on Map 0 and they've called me saying that they can't diagnose the car.

[BayouBimmer]

well I have catless dp so if I remove the jb4 I will have a CEL right?

[1cleann55]

Originally Posted by BayouBimmer

well I have catless dp so if I remove the jb4 I will have a CEL right?

Even if you leave the jb4 in with map 0 you'll get a CEL light.

[BayouBimmer]

I really hate to have to unhook it but that seems to be the only way to be sure they can connect

[mike@x-ph.com]

We recommend you completely remove it before dealer visit.
Remove it before your dealer visit, the light wont pop up until 40~50 miles.

[mashimarho]

If you leave it in Map 0 you can take it in. It takes some miles or time before it shows the CEL.

[BayouBimmer]

will I need to do a code delete first then remove?

[pduffy]

Originally Posted by BayouBimmer

will I need to do a code delete first then remove?

Yes, definitely delete codes before removing it

[Andrewe92]

clear codes/ remove jb4 or if its simple maintenance and you aren't throwing any other codes leave it in map 0 so yes to answer your question the jb4 is blocking the obd port access. in map 2 at least

[snaimpally]

Map 0 is the "passthrough" mode. Some have reported taking their car to the dealer and the dealer no noticing the JB4 while in passthrough mode. However, I'd clear the codes and then remove the JB4 before taking it to the dealer.

[Johnny Boost]

Good advice in this thread

[plus160]

I had mine in a couple of times for routine oil & maintenance cleared codes and set at 0 with no issues, but the passenger seat heater went out and the tech had to re -program the module. He found the JB4, unplugged everything
and it PUT the DME in permanent LIMP mode. I had to fork over $2000 for a new DME and it took a month to get one from Germany. I highly recommend you remove it or at least unplug everything with the battery disconnected!

[pduffy]

Originally Posted by plus160

I had mine in a couple of times for routine oil & maintenance cleared codes and set at 0 with no issues, but the passenger seat heater went out and the tech had to re -program the module. He found the JB4, unplugged everything
and it PUT the DME in permanent LIMP mode. I had to fork over $2000 for a new DME and it took a month to get one from Germany. I highly recommend you remove it or at least unplug everything with the battery disconnected!

Thats crazy! There's no way they are allowed to do that. I understand flagging the car as tuned, but this seems absurd. What did they say to you during this ordeal?

[plus160]

They called me to say they could not clear a check engine light and I thought no big deal, on the way home it was in limp mode and my SWC was not working, when I went right back and said it was undrivable and that's when they said the tech found all the extra wires and disconnected them all and hooked up the stock wires. I called Terry and he thought by hooking jb4 back up I could clear the code, but there was a code in the DME that I could not clear. and it stayed in limp mode.

So I completely removed the entire JB4 took it back to the stealer and after a couple more days of diagnosis they said the only way to fix was replace the DME, since I bought the car used and am over 50 I said I did not know anything about it and said my car was perfect before you guys messed with it but they were not buying it.

The irony is I actually emailed Mike from Roundel before I took it in and he said it should be no big deal to leave it on in the stock mode, but at the end of the Day Mike, and Terry left me hanging and the dealer actually took $650 off the DME and I used their X5 while we waited to get the new DME.

It's out of warranty now so I doubt I'll EVER take it to a dealer again unless it's something an independent can't fix but I sure hope no one else has to go through such an ordeal!

[Dark_Knight_335]

The setting that involves taking it the hell out of the car before a dealer visit LOL