NHTSA Office of Defects Investigation
Preliminary Evaluation PE12-028: Vehicle Stability Assist Malfunction
- Closed
NHTSA's Office of Defects Investigation opened Preliminary Evaluation PE12-028 on October 9, 2012 and closed it on March 15, 2013. NHTSA's investigations file lists the 2005 Honda Pilot for it.
Updated daily from NHTSA's investigations file
Key facts
- NHTSA number
- PE12-028 (also written PE12028)
- 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 March 15, 2013
- Opened
- Closed
- Vehicle or equipment manufacturer
- Honda (American Honda Motor Co.)
- Components
- Service Brakes, Hydraulic — Antilock/Traction Control/Electronic Limited Slip; Service Brakes, Hydraulic — Antilock/Traction Control/Electronic Limited Slip — Control Unit/Module
- Vehicles and equipment
- 2005 Honda Pilot
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 PE12-028.
The Vehicle Stability Assist (VSA) system in the model year (MY) 2005 Honda Pilot vehicles integrates braking control strategies for anti-lock braking, traction control, electronic stability control and brake assist functions. The system consists of a VSA modulator (an electronic control unit and electronic/hydraulic actuator) that receives data from an integral brake pressure sensor and from wheel speed sensors (four wheels), the steering wheel angle sensor and a combination yaw rate and lateral acceleration sensor.
Allegations of unexpected braking appear to be related to inappropriate activation of the brake assist (BA) function.
The BA system is designed to minimize stopping distances in emergency braking maneuvers by rapidly applying maximum braking force when a panic stop is detected. ODI's analysis of complaints and information provided by Honda in its response to DP12-002 and PE12-028 identified fault conditions that may result in false detection of a panic stop by the BA system, resulting in unexpected, severe brake application. The VSA control algorithm should detect inappropriate BA activation in less than 1 second and turn the system off. However, some complaints allege longer duration incidents of severe braking with no brake pedal application. Honda implemented countermeasures in the control and fault detection algorithm in the MY 2006 Pilot VSA modulators, which are not interchangeable with the MY 2005 parts.
Allegations of steering anomalies appear to be related to inappropriate activation of the VSA stability assist function.
The VSA system uses information from the wheel speed, steering wheel angle, yaw rate and lateral acceleration sensors to calculate the rate of change in vehicle side slip with respect to time. If excessive side slip is calculated, the system modulates brake force pulses to individual or combinations of wheels to maintain stability. ODI has identified 22 VOQs and 18 Honda reports that appear to be incidents caused by a faulty yaw rate sensor. As judged by the complainants these incidents typically last two or less seconds.
Honda identified a problem with faulty yaw rate sensors sending an incorrect yaw rate signal to the VSA modulator.
This may result in inappropriate VSA system activation, which is perceived by the driver as a momentary steering pull.
The VSA control logic is designed to detect the yaw rate sensor faults in less than one second and place the system in fail-safe mode, disabling all VSA functions.
This Preliminary Evaluation has been upgraded to Engineering Analysis (EA13-002) to further assess the scope, frequency, and safety-related consequences of the alleged defect.
The VOQs associated with the opening of this investigation are: Brake Assist: 10158094, 10160741, 10213049, 10247329, 10248833, 10257672, 10257728, 10260943, 10270110, 10279468, 10282189, 10321302, 10334571, 10360371, 10366406, 10367757, 10381501, 10382911, 10399198, 10407070, 10410421, 10427031, 10443505, 10447413, 10448010, 10450564, 10451781, 10453607, 10459818, 10464695, 10466790, 10472620, 10472803, 10479999, 10480852, 10481312, 10481341, 10481372, 10483238, 10486558, 10487248, 10487492, 10487554, 10487784, 10489358, 10492006, 10493019, 10494637.
Yaw Rate Sensor: 10481310, 10492846, 10467571, 10368257, 10491748, 10307606, 10493497, 10194731, 10351927, 10492007, 10485841, 10462811, 10476925, 10482439, 10429988, 10487141, 10482567, 10359591, 10486281, 10486397, 10380979, 10486651.
Vehicles and equipment listed for this investigation
NHTSA's investigations file lists these vehicles and equipment for Preliminary Evaluation PE12-028. 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.
Honda
Honda Pilot
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.
Honda VIN check: decode a VIN to see its year, make and model.
Sources
NHTSA's investigation record for PE12-028
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.