The Office of Defects Investigations (ODI) is an office within the NHTSA which investigates serious safety problems in the design, construction or performance of vehicles. The NHTSA is authorized to order manufacturers to recall and repair vehicles, if the ODI finds a safety issue. NHTSA investigations for the 2008 Mercury Mariner, both ongoing and closed, are listed below:

  1. INVESTIGATION: Loss of power steering while driving

    NHTSA Defect Investigation #DP15001

    • Status:
      CLOSED
    • Date Opened: April 01, 2015
    • Date Closed: June 14, 2018
    • Recall: No recall issued

    Component(s): Steering:Electric Power Assist System

    Summary: On May 27, 2014, amended June 2, 2014, Ford Motor Company (Ford) submitted a Defect Information Report (DIR) to NHTSA describing a safety defect that may result in a sudden loss of power steering assist while driving in approximately 746,067 model year (MY) 2008 through 2011 Ford Escape vehicles equipped with electric power assisted steering (NHTSA 14V-284, Ford 14S05). Ford's DIR described the defect condition as "a poor signal to noise ratio [SNR] in the torque sensor" within the Electric Power Assisted Steering (EPAS) system [which] "does not allow the PSCM to determine the driver's steering input." When the system detects this fault condition, it transitions the EPAS system to the fail-safe/manual steering mode.Ford's DIR indicates that loss of power steering assist while driving would require higher steering effort at lower vehicle speeds, which may result in an increased risk of a crash.Ford's remedy instructs dealers to check the Power Steering Control Module (PSCM) for Diagnostic Trouble Codes (DTCs) to determine the proper repair procedure. If no DTCs are present, dealers are to update the PSCM and instrument cluster module software. The updated PSCM software changes the torque sensor fault strategy so that the SNR condition does not result in a loss of power steering assist while driving.In addition, audible and visual warnings are provided for torque sensor faults.If DTCs indicating faults in the torque sensor, PSCM or Power Steering Motor (motor) are present in the initial recall inspection, the dealer performs the following repairs: 1) replaces the torque sensor for torque sensor faults (DTC B2278); or 2) replaces the steering column for faults related to the PSCM (DTC B1342) or motor (DTC B2277).Continued in attachment pages

  2. INVESTIGATION: TIRE VALVE CRACKING

    NHTSA Preliminary Evaluation #PE08060

    • Status:
      CLOSED
    • Date Opened: October 14, 2008
    • Date Closed: April 09, 2009
    • Recall: No recall issued

    Component(s): Tires:Valve

    Summary: On October 14, 2008, ODI opened PE08-060 to investigate allegations of cracked and leaking snap-in tire valves in model year (MY) 2007 vehicles manufactured by Ford Motor Company.the valves were supplied to Ford by topseal auto-parts, a subsidiary of the shanghai baolong automotive corporation in china.valves made by topseal for aftermarket sale were the subject of two recent safety recalls by tech international (08T-018) and dill air controls (08T-028), the latter of which was investigated by ODI in PE08-036 and EA08-022.the defect conditions addressed by the aftermarket tire valve recalls both involved inadequate resistance to ozone cracking due to issues with the supply of anti-ozonant chemicals to topseal for a period from July to mid-November 2006.the aftermarket valves were compounded with a blend of epdm and natural rubber, using a relatively low percentage of epdm (epdm provides inherent resistance to ozone cracking).hence, the need for anti-ozonant chemicals and the problems with cracking when those chemicals were missing or out of specification in some lots of valves.both recall campaigns involved inspection programs to identify and replace valves with visible surface cracking.although the topseal valves supplied to Ford also appear to have been affected by the anti-ozonant supply issues in mid to late-2006, Ford indicated that its valves were made at a different topseal production line and were compounded with a higher percentage of epdm rubber to meet more stringent specifications from Ford.ODI's analysis of complaint and warranty data provided by Ford showed that problems with cracked tire valves were significantly higher for MY 2007 vehicles produced from December 2006 through March 2007.Ford responded by implementing changes in its material specifications for snap-in rubber tire valves and also increasing the quality and acceptance standards for valves imported for use in its vehicles.while the complaint and warranty claim rates are elevated for subject vehicles produced from December 2006 through March 2007, the rates of leaking valves are well below one percent of production for each of the peak months for all of the affected models.a substantial majority of the subject vehicles are equipped with tire pressure monitoring systems (TPMS) which warn the driver when any tire pressures drops below 25 percent of recommended inflation pressure. As outlined in a letter to ODI dated April 6, 2009, Ford has agreed to send letters to owners of certain MY 2007 and 2008 Ford, Lincoln and Mercury vehicles to provide information about the cracking concern. Letters will be sent to owners of vehicles built from November 2006 through May 2007.owners can opt for a free dealer inspection.valves exhibiting surface cracks or air leakage related to ozone attack will be replaced by Ford under its normal warranty terms.Ford expects to send the letter by approximately mid-May 2009. Based on the use of TPMS in the majority of subject vehicles and the relatively low rates of repairs associated with leaking valves and resultant tire damage, ODI believes that the actions Ford has agreed to take will provide effective and expeditious resolution for vehicles that were built during the period when valves with inadequate resistance to ozone cracking were most likely to have been used in vehicle production.further investigation of this matter would not be an efficient allocation of Agency resources.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.