Stuck throttle

Preliminary Evaluation (PE)12-005 was opened to investigate allegations of speed control cables detaching from the throttle body and subsequently interfering with the throttle closing fully to the idle position in model year (MY) 2005 and 2006 Ford Taurus vehicles. The speed control cable, throttle body attachment arm (“nail head”) for the speed control cable, cable mounting bracket and cable routing for the MY 2005 and 2006 Ford Taurus are common to all MY 2004 through 2006 Ford Taurus and Mercury Sable vehicles equipped with either the 155 HP 3.0L 2-valve Vulcan engine or the 200 HP 3.0L 4-valve Duratec engine (the “subject vehicles”). Figures 1 and 2 show the throttle body cam and speed control cable installed and a cable interference condition caused by contact between a detached cable and the “nail head.” Ford’s assessment of the condition in incident vehicles noted that the interference conditions produced tended to be short in duration as the cable end tended to dislodge itself from the throttle body due to vibration, road loads or engine roll in addition to tapping the acceleration pedal. Ford inspected three incident vehicles and measured maximum throttle openings of 5.8% to 14.9%, resulting in engine speeds ranging from 1600 to 2200 rpm with the transmission selector in Drive. A Ford stack-up analysis of the speed control cable length from the attachment bracket to the throttle body indicated a maximum theoretical throttle opening of 16.4% that could result from the alleged defect. Engineers at the NHTSA Vehicle Research and Test Center (VRTC) inspected an incident vehicle to evaluate throttle positions and engine speeds that could result from the alleged defect and performed brake testing of a vehicle with the throttle stuck at the worst case throttle opening that could result from the condition. The VRTC vehicle inspection noted that, depending on the orientation of the detached cable end, the amount of throttle opening that could result from interferenc