Investigations
VACUUM BRAKE BOOSTER FAILURE
NHTSA Preliminary Evaluation PE05009 - closed, opened 2005-02-10 and involving the TOYOTA TOYOTA.
NHTSA investigation PE05009 is a Preliminary Evaluation opened on 2005-02-10 and currently closed. The subject of record is TOYOTA TOYOTA, which places this file inside the Office of Defects Investigation queue for TOYOTA. Latest activity on this investigation was logged on 2005-06-15 - NHTSA updates that field whenever an Information Request goes out, a supplement is filed, or a status change is recorded in the public docket.
A Preliminary Evaluation like PE05009 is the entry point of the federal defect-investigation process. NHTSA engineers scan complaint databases, field reports, and manufacturer data to decide whether an Engineering Analysis is warranted, whether a voluntary recall is already sufficient, or whether the pattern does not rise to a defect finding.
Investigators summarized the matter as follows: "ON FEBRUARY 10, 2005, THE OFFICE OF DEFECTS INVESTIGATION (ODI) OPENED A PRELIMINARY EVALUATION TO INVESTIGATE ALLEGED LOSS OF BRAKE POWER-ASSIST IN CERTAIN 2004 MODEL YEAR (MY) LEXUS RX330 VEHICLES BUILT THROUGH APPROXI..." Investigations are the early-warning layer of the federal auto-safety system, sitting upstream of formal recalls and defect orders. Whether this one closes without action or escalates into an Engineering Analysis, the full history stays in the ODI archive so researchers, litigators, and buyers can pull the paper trail at any time. Related TOYOTA files, listed below, give context on whether this is an isolated concern or part of a broader pattern across the brand.
Investigation Summary
ON FEBRUARY 10, 2005, THE OFFICE OF DEFECTS INVESTIGATION (ODI) OPENED A PRELIMINARY EVALUATION TO INVESTIGATE ALLEGED LOSS OF BRAKE POWER-ASSIST IN CERTAIN 2004 MODEL YEAR (MY) LEXUS RX330 VEHICLES BUILT THROUGH APPROXIMATELY JUNE 30, 2004. THE SUBJECT VEHICLES WERE MANUFACTURED AT TOYOTA MOTOR MANUFACTURING CANADA, INC.¿S CAMBRIDGE, ONTARIO ASSEMBLY PLANT AND WERE EQUIPPED WITH VACUUM BRAKE BOOSTER ASSEMBLIES SOURCED FROM AISIN SEIKI CO., LTD (AISIN) SUBSIDIARY ADVICS NORTH AMERICA, INC. (ADVICS-NA). TO DATE, ODI IS AWARE OF 146 NON-DUPLICATIVE REPORTS THAT ALLEGE LOSS OF BRAKE POWER-ASSIST AND 6 CRASHES ALLEGEDLY CAUSED BY LOSS OF BRAKE POWER-ASSIST (RESULTING IN 1 MINOR INJURY) ON THE SUBJECT VEHICLES. THE SUBJECT VEHICLES USE A CONVENTIONAL BRAKE BOOSTER ASSEMBLY THAT CONTAINS A RUBBER DIAPHRAGM TO SEPARATE THE FORE AND AFT PRESSURE CHAMBERS. THE OUTER EDGE OF THE RUBBER DIAPHRAGM IS HELD IN PLACE VIA A RETAINING GROOVE ON THE BRAKE BOOSTER BODY. IF THE BOOSTER LOSES VACUUM (E.G., OPERATOR DEPLETES THE VACUUM BY PRESSING THE BRAKE PEDAL SEVERAL TIMES WHILE THE ENGINE IS OFF), IT MAY CAUSE THE DIAPHRAGM TO DEFORM IN THE AREA OF THE RETAINING GROOVE TO THE POINT THAT INSUFFICIENT SEAL EXISTS BETWEEN DIAPHRAGM AND BOOSTER BODY, THUS CAUSING A MOMENTARY LOSS OF BRAKE POWER-ASSIST. THE ADVICS-NA SUPPLIED DIAPHRAGM HAS SLIGHTLY DIFFERENT MATERIAL PROPERTIES COMPARED TO THE DIAPHRAGM INSIDE BRAKE BOOSTERS SUPPLIED BY ADVICS JAPAN, CORP. (ADVICS-J) AND USED ON 2004MY LEXUS RX330 VEHICLES MANUFACTURED AT TOYOTA MOTOR KYUSHU, INC.¿S ASSEMBLY PLANT. THE SOFTER RUBBER USED IN THE ADVICS-NA DIAPHRAGM ALLOWS GREATER DEFORMATION AND IS LESS RESILIENT WHEN COMPARED TO THE ADVICS-J DIAPHRAGM. LOSS OF BRAKE POWER-ASSIST MOST OFTEN OCCURS AT VEHICLE START-UP AND APPEARS TO BE MORE PREVALENT IN COLDER TEMPERATURES. MOST OWNERS REPORT THAT BRAKE SYSTEM OPERATION RETURNS TO NORMAL WITHIN A FEW SECONDS AFTER VEHICLE START-UP. TESTING CONDUCTED BY THE MANUFACTURER INDICATES THAT THE A
About This Investigation Type
A Preliminary Evaluation (PE) is the first phase of NHTSA's investigation process. It is opened when the agency identifies a potential safety defect pattern, usually triggered by consumer complaints, manufacturer reports, or field monitoring. During a PE, NHTSA gathers information to determine whether a formal engineering analysis is warranted.
Other TOYOTA Investigations
Brake Actuator Valve Wear
Electrical problems / No-start
Joyson Passenger Side Air Bag Cushion
Battery Hold Down Bracket Thermal Events
Brake Actuator Valve Wear
Data from NHTSA Office of Defects Investigation. Cross-references: NHTSA recall campaign API and NHTSA FARS where fatality records overlap. PlainCars does not rate or recommend vehicles. about how PlainCars sources NHTSA data.
Read our methodology - how this data is sourced, computed, and verified.