The problem first emerged as two cylinders misfiring and the resulting "codes". After considerable testing by the our auto mechanic, the problem was tracked down to two fuse links in the OEM wiring harness melting together rather than separating to break the circuit as they should have done. The very high voltage (our mechanic reported 30,000 volts) that back fed through the melted fuse links fried the two spark plug coils and the main CPU (powertrain control module). Total cost of the repair was $2700 plus three weeks of the vehicle being out of service. The very high voltage and damage caused to key engine compartment components could have easily led to an engine failure and possibility engine compartment fire.

The situation has been reported to NHTSA with record number of 11015637.

Our mechanic reported that Volkswagen had redesigned the fuse links on the replacement OEM wiring harness. A VW technical bulletin also reported the wiring harness as a potential problem. Clearly Volkswagen had installed in the vehicle when originally assembled a part (the wiring harness) that was incorrectly designed and now a known defect. The responsible action would have been a voluntary recall by Volkswagen to replace the defective part and avoid the severe secondary damage and risk to the public.