BRAKE LIGHT SWITCH FAILURE

ON JUNE 16, 2005, THE OFFICE OF DEFECTS INVESTIGATION (ODI) OPENED A PRELIMINARY EVALUATION TO INVESTIGATE ALLEGED STOP LAMP (BRAKE) SWITCH FAILURES IN CERTAIN MODEL YEAR (MY) 2004 LAND ROVER DISCOVERY SERIES II VEHICLES. ODI SENT A LETTER TO THE MANUFACTURER ON JUNE 24, 2005 REQUESTING INFORMATION ABOUT THESE AND OTHER LAND ROVER VEHICLES. ANALYSIS OF MANUFACTURER DATA SHOWS A HIGH FAILURE FREQUENCY FOR STOP LAMP SWITCHES ON SUBJECT VEHICLES MANUFACTURED FROM APPROXIMATELY DECEMBER 2, 2003 THROUGH MAY 13, 2004. ALL 8,763 SUBJECT VEHICLES BUILT DURING THIS PERIOD WERE EQUIPPED WITH A SELF-ADJUSTING STOP LAMP SWITCH SUPPLIED BY METHODE ELECTRONICS MALTA, LTD. (METHODE). IN SEPTEMBER 2003, METHODE MOVED THE PRODUCTION OF AN INTERNAL SWITCH COMPONENT, KNOWN AS THE SLIDER MECHANISM, FROM A VALIDATED PLASTIC INJECTION MOLDING TOOL (¿CAVITY 1¿) TO ANOTHER TOOL (¿CAVITY 2¿) THAT HAD NOT BEEN USED BEFORE TO PRODUCE PARTS FOR LAND ROVER. SLIDERS FROM CAVITY 2 MAY BE CHARACTERIZED BY POOR FILL AND LACK OF DEFINITION IN THE SLIDER TEETH. CONSEQUENTLY, THE SLIDER IS UNABLE TO RESTRAIN IMPROPER MOVEMENT OF THE PLUNGER DURING NORMAL BRAKE PEDAL OPERATION. THIS CAUSES THE SWITCH TO FALL OUT OF ADJUSTMENT, THUS SIGNIFICANTLY REDUCING THE EFFORT REQUIRED TO ENERGIZE THE SWITCH AND ILLUMINATE THE STOP LAMPS. THE MOST COMMON SYMPTOM DESCRIBED BY COMPLAINANTS AND DOCUMENTED IN WARRANTY CLAIM RECORDS IS STOP LAMPS THAT REMAIN CONSTANTLY ILLUMINATED. DOCUMENTS PROVIDED BY THE MANUFACTURER INDICATE THAT CERTAIN MY 2002 THROUGH 2005 LAND ROVER FREELANDER VEHICLES USE A SUBSTANTIALLY SIMILAR STOP LAMP SWITCH THAT ALSO SUFFERS FROM A HIGH FAILURE FREQUENCY. THIS INVESTIGATION HAS BEEN UPGRADED TO AN ENGINEERING ANALYSIS (EA05-016) TO FURTHER STUDY THE FREQUENCY, SCOPE AND SAFETY CONSEQUENCES OF THE ALLEGED DEFECT.