NHTSA Office of Defects Investigation
Preliminary Evaluation PE11-018: Idle instability
- Closed
NHTSA's Office of Defects Investigation opened Preliminary Evaluation PE11-018 on May 11, 2011 and closed it on February 7, 2013. NHTSA's investigations file lists 3 models from 2 makes for it.
Updated daily from NHTSA's investigations file
Key facts
- NHTSA number
- PE11-018 (also written PE11018)
- Investigation type
- Preliminary Evaluation The first stage of most defect investigations: NHTSA's Office of Defects Investigation gathers basic information about a possible safety defect, including from the manufacturer.
- Status
- Closed February 7, 2013
- Opened
- Closed
- Vehicle or equipment manufacturer
- Ford Motor Company
- Component
- Vehicle Speed Control
- Vehicles and equipment
- 3 models from 2 makes, including the Ford Five Hundred and Ford Freestyle
A recall appears here only when NHTSA's investigations file links one to the investigation; NHTSA's summary or record can name others.
NHTSA's summary
As NHTSA's Office of Defects Investigation wrote it for Preliminary Evaluation PE11-018.
On November 29, 2012, Ford Motor Company (Ford) initiated Customer Satisfaction Program 12N03 to extend warranty coverage terms for repair of engine idle RPM surge caused by throttle body deposits in all model year (MY) 2005 through 2007 Ford Freestyle, Five Hundred and Mercury Montego vehicles.
The program extends the coverage for up to 10 years of service or 150,000 miles from the warranty start date of the vehicle (all vehicles are eligible for the program through May 31, 2013, regardless of mileage).
Dealers will repair vehicles exhibiting the condition by removing and cleaning the throttle body and reprogramming the PCM with software containing an updated idle speed control strategy.
According to Ford, some of the affected vehicles may experience momentary, intermittent engine idle RPM surge (idle flare) when stopped or during low speed driving maneuvers such as in a parking lot or driveway.
Unstable idle speed control (dips and flares) around the target engine speed (700 rpm) can occur in vehicles with deposit build-up in the throttle body when the system adjusts engine speed in response to changes in engine load, typically from power steering application or air-conditioner compressor cycling.
Idle speed control logic is only active at vehicle speeds below 3.5 mph and when the accelerator pedal is not applied.
Ford testing of a vehicle with a worst case throttle body measured a maximum idle flare of 1360 RPM lasting approximately 1 second, which Ford indicated was consistent with system design to limit vehicle speed and acceleration in idle control mode.
Ford indicated that the test vehicle was held in place with normal brake effort and that vehicle speed remained under 4 mph without the brake pedal applied.
In addition to throttle body deposit accumulation, symptoms associated with the condition may include Check Engine lamp illumination and diagnostic trouble codes (DTCs) P0505, P0506 or P061B.Ford attributed the surge condition to changes in idle air flow resulting from the progressive buildup of deposits in the throttle body from normal Positive Crankcase Ventilation (PCV) system operation.
This condition was not adequately compensated for in the original Powertrain Control Module (PCM) calibration.
Ford issued a technical service bulletin on August 15, 2011 (TSB 11-8-5), releasing an updated powertrain control calibration for vehicles with CVT transmissions.
On October 19, 2011, Ford issued a second bulletin (TSB 11-10-21) superseding TSB 11-8-5 and including updated powertrain control calibration for vehicles with 6-speed transmissions.
Prior to Ford issuing the TSB?s, owner?s experiencing the alleged defect either received no repairs, if dealers could not duplicate the condition, or had the throttle body cleaned or replaced, which only provided temporary correction until the throttle deposit build-up returned.
Ford?s revised powertrain calibrations appear to be effective remedies for the idle instability caused by build-up of throttle body deposits.
However, even after the TSB?s were released, many owners experiencing the condition continued to have difficulty with proper diagnosis and repair as dealers were often either unable to duplicate the condition or were unfamiliar with the new repair procedures.
Ford's new program addresses those concerns.
NHTSA's testing and complaint analysis indicate that the idle speed control issue in the subject vehicles can only occur at very low speeds, are very brief events, are easily controlled by moderate brake pedal forces and result in minor increases in vehicle speed even with no braking.
This investigation is closed.
The closing of this in
Vehicles and equipment listed for this investigation
NHTSA's investigations file lists these vehicles and equipment for Preliminary Evaluation PE11-018. A listed model year means only that an investigation names it; it says nothing about any particular vehicle. Model years with a try.vin recall page link to that page's NHTSA investigations section.
What an NHTSA investigation is
NHTSA's Office of Defects Investigation (ODI) looks into possible safety defects in vehicles and equipment, often after owner complaints. An investigation usually starts as a Preliminary Evaluation, or as a Recall Query when it concerns whether an existing recall covers the right vehicles or fixes the problem, and ODI can upgrade it to a more detailed Engineering Analysis. A Defect Petition asks NHTSA to open an investigation, and Audit and Equipment Queries are administrative investigations into whether companies complied with federal vehicle safety requirements, such as reporting, recall and certification rules.
An open investigation is not a finding that a safety defect exists, and NHTSA can close one without a recall.
To see whether a specific vehicle has an open recall, enter its VIN at nhtsa.gov/recalls.
Free VIN check: decode a VIN to see its year, make and model.
Sources
NHTSA's investigation record for PE11-018
Investigation details come from NHTSA's investigations file, which try.vin imports once a day. The investigation types are described from the U.S. Department of Transportation Inspector General's May 2023 report on NHTSA's Office of Defects Investigation, NHTSA's petition rules (49 CFR Parts 552 and 557) and NHTSA's Office of Defects Investigation procedures. How try.vin reads NHTSA investigations.