NHTSA Defect Investigation #EA04018

LOSS OF ELECTRIC POWER STEERING: Steering:Electric Power Assist System**

CLOSED

no recall issued

** This defect investigation is filed under 2 related vehicle components.
2004 CHEVROLET MALIBU -- In performing this engineering analysis, ODI determined that the electric power steering system in the subject vehicles can malfunction or fail, causing the driver to lose power steering assistance; however, due to the following reasons, ODI has decided that further expenditure of Agency resources on this investigation is not warranted at this time: - GM issued customer satisfaction campaign (csc) 04050A indecember 2004 to address the alleged defect in approximately58,700 subject vehicles, encompassing at least 97 percent of thecomplaint and warranty claims population.vehicles outside thecsc 04050A population contain a newly designed torque andposition sensor and have experienced a relatively low complaintrate.this customer satisfaction campaign presently has acompletion rate of 52%. - the impact on the driver¿S ability to control these relativelysmall and light vehicles was limited.VRTC test engineers wereunable to induce a failure mode that would cause the eps tosubstantially limit the driver¿S ability to turn the vehicle in aparticular direction or to provide the driver with unintendedpower assistance.- there is no risk of fire.accordingly, this investigation is closed.the closing of this investigation does not constitute a finding by NHTSA that a safety-related defect does not exist.the Agency will continue to monitor complaints and other information relating to the alleged defect in the subject vehicles and take further action in the future if warranted by the circumstances.(for further details see attached engineering analysis (EA04-018)closing report.) Investigation was initiated on July 01 2004. Closed on May 10 2005. For detailed information & supporting documents, see the official NHTSA page concerning investigation #EA04018 »

NHTSA Defect Investigation #PE04031

LOSS OF ELECTRIC POWER STEERING: Steering:Electric Power Assist System**

CLOSED

no recall issued

** This defect investigation is filed under 2 related vehicle components.
2004 CHEVROLET MALIBU -- ODI opened PE04-031 based on eight reports of alleged power steering failure in the subject vehicles.the complaints allege that the driver suddenly lost all electric power steering assistance without warning making the vehicle difficult to steer. The subject vehicle utilizes an electric power steering assist system (eps) that provides variable steering assistance based on steering wheel torque, steering wheel postion, and vehicle speed.General Motors documents identified the following two factors that contributed to the alleged defect in the subject vehicles: A.contamination of the torque and position sensor from theseparation of grease applied to the steering column assembly. B.electrical noise generated on the power and ground slip ring surfaces of the torque and position sensor.the noise is generated as the sensor contact brushes move along the slip ring surfaces when the steering wheel is rotated.ODI's analysis showed failurerates that are of concern to ODI and indicated that the alleged defect is continuing to occur in the subject vehicles. This preliminary evaluation has been upgraded to an engineering analysis to further investigate this concern, to assess the potential safety-related consequences, and to determine the scope of the affected population. Investigation was initiated on March 30 2004. Closed on July 01 2004. For detailed information & supporting documents, see the official NHTSA page concerning investigation #PE04031 »