Engineering Analysis · Closed
Loss of power steering assist
Manufacturer: BMW of North America, LLC
This investigation led to a recall
NHTSA links this probe to recall campaign 15V660000.
Read the recall: what is defective and the free fix →What NHTSA is examining
The Office of Defects Investigation (ODI) originally opened the investigation of loss of power steering assist in model year (MY) 2004 and 2005 Mini Cooper as Preliminary Evaluation PE10-038.The investigation was upgraded to Engineering Analysis EA11-005 in May, 2011.During EA11-005 the scope was expanded to include MY 2002 and 2003 vehicles that use the same steering system.The subject vehicles now include MY 2002, the first year BMW sold MINI in the U.S., through mid-MY 2005 covering approximately 109,000 vehicles.The subject vehicles use an electrically driven pump to provide hydraulic pressure to a conventional rack-and-pinion steering gear.A pump, the electric motor, and an electronic control unit (ECU) are housed in a single component BMW calls a Power Pack.The investigation focused on contaminant-induced failure of the ECU resulting in a loss of assist without warning.When assist is lost mechanical steering is retained however increased steering effort is required to keep the vehicle on an intended path.Some consumers reported that restarting the vehicle (cycling the ignition switch) would often reinstate the steering assist.Additionally, and by design, assist can also reinstate during the drive cycle in limited circumstances.The unexpected loss of assist, and/or possibly the reinstatement of assist while driving, may contribute to a loss of vehicle control in certain driving situations.During MY 2005 production BMW introduced a revised Power Pack design (the ECU…
Vehicles under investigation
Source: NHTSA Office of Defects Investigation records, updated daily. An investigation is not a determination that a defect exists; many probes close without a recall.