Steering:Electric Power Assist System

Date Announced
Vehicles Affected
NHTSA Campaign #
The Office of Defects Investigation (ODI) opened a preliminary evaluation to investigate complaints of the loss of power steering while driving. The subject vehicles are equipped with a rack mounted Electric Power Assisted Steering (EPAS) unit.Some of the complaints alleged that the steering assist failed and resulted in increased steering efforts that contributed to a loss of control and in some cases a crash.The EPAS system was manufactured by TRW Automotive for Ford and was designated as Generation I.These units were first produced and put into vehicle production in July 2008 beginning with the model year (MY) 2010 Ford Fusion and Mercury Milan.The system is comprised of a mechanical steering rack-and-pinion gear with torque sensor, electric assist motor, motor position sensor and a power steering control module (PSCM). The PSCM is self-monitoring and designed to detect faults within the system and can store diagnostic trouble codes (DTCs) if a problem is detected.There are 29 potential DTCs the system can detect.Many of these allow the system to go into reduced-assist steering mode by using the default vehicle speed signal should the live speed signal be lost, if voltage to EPAS system falls below 10.7 or goes above 17 volts, the temperature at the PSCM goes above 105C (221F), or if high friction is detected.Some DTCs will cause the system to go into manual steering mode (no assist). On July 1, 2015, Ford filed a Defect Information Report (DIR) identifying a safety related defect in TRW GEN I EPAS systems installed in some of the subject vehicles (NHTSA Recall 15V-340, Ford No. 15S18).The DIR indicated that intermittent electrical connections caused by quality issues associated with conformal coat contamination and ribbon cable pin misalignment within the steering gear motor may lead to a loss of the motor position sensor signal, resulting in a sudden loss of power assist while driving.The recall covers approximately 393,623 vehicles built from September 2010 through February 2012:2011-12 Fusion built SEP 2010 - FEB 2012; 2011-12 Lincoln MKZ built SEP 2010 - FEB 2012; 2011 Milan built SEP 2010 - DEC 2010; 2011-13 Taurus built SEP 2010 - FEB 2012; 2011-13 Flex with 3.5L GTDI engine built SEP 2010 - FEB 2012; and 2011-13 MKS, MKT with 3.5L GTDI engine built SEP 2010 - FEB 2012.The repair consists of updating the PSCM software to prevent a loss of steering assist while driving. The revised software will provide audible and visual warnings to the driver. If one or more of the following DTCs are stored, C1B00-62, C200B-2F, C200B-61, C200B-62, C200C-2F, C200D-49, U0300-00, U2011-49, U2011-61, U3000-46, U3000-49, U3000-61, U3000-72, U3000-96, P07AE-09, the dealer will replace the EPAS system at no charge to the owner.ODI's analysis of failure data for this PE identified a total of 2,584 complaints to ODI and Ford and 9,967 Ford warranty claims related to the alleged defect.The recalled vehicles account for 1,634 of the complaints and 7,311 of the warranty claims.ODI's analysis identified 40 complaints alleging crashes that may be related to loss of steering assist while driving, 20 of which involved vehicles included in Ford's recall.The information available for the alleged crashes were not sufficient to assess specific causes of the incidents or to verify EPAS malfunctions in each case.Most of the crashes were low-speed impacts with curbs or roadside objects resulting in wheel or minor body damage.None of the injury claims indicated medical attention was required.In addition, statistical modeling of the failure data by NHTSA's National Center for Statistics and Analysis projected 10-year failure rates of approximately 8-14 percent for the recalled vehicles and approximately 1 percent for the non-recalled subject vehicles.This investigation is closed.All ODI complaints associated with this closing resume are listed in the Attachment.
Documents (13)