I have a 2009 GMC Sierra 4wd 1500 extended cab with 6 foot box.Does anyone know for sure what the latest and greatest Part number is for sure. The original left door lock actuator lasted 4.5 years, it quit working so being a x-GM tech working for a different car manufacturer now I bought part number 25876385 from a GM dealer off of ebay for $96 all was well for 9 months and the replacement has quit again what a joke!!! Did not even last year!!! Beginning to wonder if all the different part numbers for this same door lock actuator that can be used on the various years makes and models have the same trademarks of those engineers who tried to cover there rears with the ignition switch debacle, So.... Mary this is how the "NEW" GM operates? Looks & sounds like the old GM to me after seeing what a joke these door lock actuators are, I previously owned a 1994 Full size Chevy truck never even changed a turn signal bulb let alone a door lock actuator or any switch on that vehicle.I've also had to replace the drivers door window switch on the 2009 GMC Sierra, These parts should practically last the life of the vehicle not be changed with every oil change or tire rotation, brake job.GM needs to step up here and least offer free replacements or discount, the part is not worth 90-150 bucks per actuator for role of the dice hoping you get one that lasts 4-5 years. Anyone from the "NEW" GM car to chime in I'm all ears......