PE12028 · PE
SERVICE BRAKES, HYDRAULIC:ANTILOCK/TRACTION CONTROL/ELECTRONIC LIMITED SLIP:CONTROL UNIT/MODULE Investigation
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.
DP12002 · DP
ELECTRONIC STABILITY CONTROL Investigation
In a letter dated April 9, 2012, a consumer petitioned the National Highway Traffic Safety Administration (NHTSA) to initiate a defect investigation of alleged stability control failures in model year (MY) 2005 Honda Pilot vehicles. The petitioner alleged that, in the malfunctioning of these systems, steering failures occur and the brakes apply involuntarily. On June 4, 2012 the Office of Defects Investigation (ODI) opened Defect Petition DP12-002 to evaluate whether to grant or deny the petition. The petition is hereby granted. The Vehicle Stability Assist (VSA) system in the 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 the DP12-002 information request letter have identified fault conditions that may result in false detection of a panic stop by the BA system, resulting in unexpected, severe brake application. ODI's analysis of consumer complaints has identified 185 incidents of unexpected braking of varying duration, including several allegations of rapid decelerations from highway speeds to near stops in highway travel lanes (VOQs 10450564, 10467571, 10427031, 10257672, 10453607). 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.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 failsafe mode, disabling all VSA functions. ODI has identified a total of 20 complaints that appear to be related to inappropriate VSA activation.The petition is granted.Preliminary Evaluation PE12-028 has been opened to assess the scope, frequency, and safety-related consequences of the alleged defect.
EA11012 · EA
EXTERIOR LIGHTING:HEADLIGHTS:SWITCH Investigation
This investigation was prompted by Preliminary Evaluation (PE) 11-017, and was based on reports from consumers alleging that both low beam headlights stopped illuminating simultaneously.Some complainants also reported that the combination switch (switch) that controls the headlights and turn signals, and/or its electrical wiring harness connector were damaged by overheating.ODI's PE information request letter asked Honda for certain data on model years (MY) 2002-2006 CR-V, 2003-2008 Pilot, 2003-2008 Element, 2001-2005 Civic, and 2000-2001 S 2000 vehicles.Analysis of complaint and Honda data show that a complete low beam headlight circuit failure occurs in models with 2-bulb headlight systems (i.e., a single bulb on each side for high and low beam).Models with 2-bulb systems include MY 2002-2004 CR-V, 2003-2005 Pilot, 2001-2003 Civic, and 2003-2008 Element.Models with 4-bulb headlight systems (i.e., two bulbs on each side, one for high and one for low beam) have different electrical circuits for the headlights and do not experience the same failure mechanism as the 2-bulb system.MY 2000-2001 S 2000 models with 2-bulb high intensity discharge headlights also have different electrical circuits for the headlights and do not experience the same failure mechanism.Honda introduced the 4-bulb headlight system in CR-V in MY 2005, in Pilot in MY 2006, and in Civic in MY 2004.On March 29, 2012 Honda submitted a defect information report (DIR) to recall 554,428 vehicles, including MY 2002-2004 CR-V and MY 2003 Pilot.In the DIR, Honda stated that tension from the combination switch wiring harness to the electrical terminal for the low beam headlight circuit could cause a small amount of motion as the combination switch was operated.This motion, over time, can wear the surface of the terminal creating copper oxide, increasing electrical resistance, which may cause the terminal to melt within the harness connector.ODI continued its investigation, and on August 31, 2012 Honda submitted another DIR to recall an additional 820,789 vehicles.This report included the MY 2002 Civic vehicles which were not subject to a prior safety recall (04V-086) for headlights, all of MY 2003 Civic, and MY 2004-2005 Pilot.Honda's DIR advised that operation of the turn signal switch lever at high speed and/or with heavy force can cause movement between the combination switch body and the sub-harness wiring connector.This can cause wear and continued movement can create copper oxide, increasing electrical resistance, and potentially causing the terminal to melt within the harness connector. Please see both DIRs at http://www-odi.nhtsa.dot.gov/recalls/ under safety recall 12V-136 for complete details.Honda also provided additional information on the Element model, stating that it was not recalled due to it's very low failure rate.Honda sold 301,497 Element vehicles in the United States and received 17 reports, while ODI received one report (see VOQ 10395219).Honda's technical explanation for the low rate, which was submitted under request for confidentiality, is that the headlight switch, as installed in the Element, reacts differently to the forces applied to it as compared to the recalled models.See attachment for additional information.