Originally Posted by Mike@N54Tuning.com
The jb4 is passive and can't hurt anything. Your shop is probably clueless. I'd get the car out of there before they run up a huge bill on your tab for what should be a 5 min fix. Send bms photos of your wiring and they should be able to point you in the right direction.
Indeed - get your car out of there and find a shop that knows tuned N54s.
Your shop doesn't know enough to continue proper diagnosis. If you need to remove the JB4 physically for them to continue, then do so. Otherwise I've only had to put the JB4 into Map 0 / passthrough to continue communications.
E92 335i/6MT Dinan Stage 3: intercooler, oil cooler, intake, flash, exhaust, LW dual-mass flywheel.
Vishnu PWM methanol custom trunk mount, Diffsonline 3-clutch Salisbury custom diff, Ohlins Road and Track coilovers, Vorshlag camber plates, much more...
E28 M5 w/ buncha stuff, R171 SLK350