Preliminary Evaluation · THROTTLE CONTROL SYSTEM · Opened 2004-03-03 · Closed 2004-07-22
Investigation
Action number
PE04021
Type
Preliminary Evaluation
Open date
2004-03-03
Close date
2004-07-22
Manufacturer
Toyota Motor Corporation
Affected makes
LEXUS; TOYOTA
Affected components
VEHICLE SPEED CONTROL
Affected model years
2002, 2003
Affected (make, year) variants
6
Summary
THE LEXUS MODELS WERE THE SUBJECT OF DEFECT PETITION (DP) 04-003.TWELVE ODI COMPLAINTS ARE DUPLICATIVE TO TOYOTA REPORTS, INCLUDING THE TWO MINOR CRASHES.THE V6 EQUIPPED SOLARA MODELS HAVE BEEN EXCLUDED BECAUSE THEY DO NOT CONTAIN THE SUBJECT THROTTLE CONTROL SYSTEM.TOYOTA INTRODUCED ELECTRONIC THROTTLE CONTROL (ETC) ON THE SUBJECT VEHICLES BEGINNING IN MODEL YEAR (MY) 2002.ODI OPENED THE INVESTIGATION TO DETERMINE IF THE SYSTEM COULD BE THE CAUSE OF COMPLAINTS ALLEGING THE ENGINE SPEED INCREASED, OR FAILED TO DECREASE, (FOR A SHORT DURATION) WHEN THE ACCELERATOR PEDAL WAS NOT DEPRESSED (THE ALLEGED DEFECT).DURING THE COURSE OF THE INVESTIGATION, ODI ANALYZED AGENCY DATA AND REVIEWED VEHICLE OWNER QUESTIONNAIRE (VOQ) REPORTS, CONDUCTED INTERVIEWS INVOLVING 113 VOQ AND 36 TOYOTA REPORTS, INSPECTED TWO COMPLAINANT VEHICLES, REVIEWED RELEVANT TOYOTA SERVICE AND NEW CAR FEATURE DOCUMENTATION, REVIEWED AND ANALYZED TOYOTA?S RESPONSES TO ODI?S INFORMATION REQUEST LETTER, CONDUCTED A LIMITED CONTROL PEDAL ASSESSMENT, AND ATTENDED A TOYOTA TECHNICAL PRESENTATION THAT INCLUDED THE ASSESSMENT OF TWO DEMONSTRATION VEHICLES.THROUGH INTERVIEWS, ODI IDENTIFIED 14 VOQ AND 6 TOYOTA REPORTS (20 UNIQUE VEHICLES) WHERE COMPLAINANTS REPORT MULTIPLE OCCURRENCES OF THE ALLEGED DEFECT.IN SOME CASES THE CONDITION WAS EXPERIENCED BY DIFFERENT VEHICLE OPERATORS OR WAS WITNESSED BY OTHER OCCUPANTS.ODI WAS UNABLE TO MAKE A DETERMINATION AS TO THE CAUSE OF 9 TOYOTA AND AN ADDITIONAL 37 VOQ REPORTS (WHICH DESCRIBE 28 UNIQUE INCIDENTS) DUE TO INSUFFICIENT INFORMATION.THE REMAINING COMPLAINANTS INTERVIEWED (62 VOQ, 21 TOYOTA) DESCRIBED CONDITIONS NOT CAUSED BY A FAILURE OF THE THROTTLE CONTROL SYSTEM AND WERE THUS CONSIDERED UNRELATED TO THE INVESTIGATION.NONE OF THE COMPLAINANTS INTERVIEWED REPORTED A COMPONENT FAILURE (OR OTHER INDICATOR OF A SYSTEM FAILURE) AS THE POTENTIAL CAUSE OF INCIDENTS RELEVANT TO THIS INVESTIGATION.IN MANY CASES, THE COMPLAINT VEHICLES WERE SUBSEQUENTLY INSPECTED BY DEA