I'm having an issue with bag Com connecting to my car. It was not my system, but it was up to date, the full version, and had a genuine Ross Tech cable. Whenever we tried to access the ecm or ccm it would give a "too many communication errors to continue" error. I have a stock Volkswagen tape player and VCDS connected to the radio and locks. My generic scanner connects to my car and reads codes just fine. I have had my car at the dealership twice for an O2 sensor recall and they haven't been able to connect to my car either. I am certain that this is a wiring issue. I would like to know what the most common wiring issues are on the New Beetle and mk4 Golf+Jetta so that I can hopefully find my issue. I have checked all fuses and all are good. Please help! I'm so frustrated with this, I'm about to just get a new(to me) wiring harness and install it. I just want to know of common wiring issues, I've researched this and checked everything that was suggested on other forums for this issue. Thanks in advance!