Vehicle had previously backfired periodically, especially when downshifting. Was starting from full stop, engine was sputtering, check engine light was on, tachometer was below 500 RPM. Vehicle was drivable, but acceleration was difficult due to sputtering engine. Drove directly to dealer - vehicle was diagnosed and repaired same day (04/15/2013). Service writer provided copy of factory technical service bulletin #12--fl-007 (July 2012), which states as follows. "this bulletin provides information related to the gdi idb (injector driver box) ECU software update of some 3.3L/3.8L vehicles that may experience any of the following dtc stored: P0300: Random/multiple cylinder misfire detected P0301: Cylinder 1 - misfire detected P0302: Cylinder 2 - misfire detected P0303: Cylinder 3 - misfire detected P0304: Cylinder 4 - misfire detected P0305: Cylinder 5 - misfire detected P0306: Cylinder 6 - misfire detected" service writer verbally advised that misfire was detected in cylinder 5, but this problem was not stated on repair order. He also indicated that problem may recur. Dealer should have notified all existing vehicle owners at time technical service bulletin was issued.

- Plantation, FL, USA