Preliminary Evaluation PE08-027: ENGINE STALLING - FUEL PUMP FAILURE

IN RESPONSE TO ODI'S INFORMATION REQUEST FOR PE08-027, VOLKSWAGEN AG (VW) STATED THAT IT BELIEVES THAT THE POSSIBLE CAUSAL OR CONTRIBUTORY FACTORS OF THE ALLEGED DEFECT IN THE SUBJECT VEHICLES COULD RESULT FROM EXCESSIVE ACCUMULATION OF FOREIGN MATERIALS IN THE FUEL FILTER.IN RARE CASES, THE FUEL FILTER COULD BECOME CLOGGED, WHICH CAN CAUSE INCREASED PRESSURE ON THE PUMP.VW INDICATED THAT ENGINE STALLS RESULTING FROM THIS CONDITION ARE RARE AND WOULD BE PRECEDED BY SYMPTOMS SUCH AS REDUCED ENGINE POWER, NOISE OR HESITATION.ODI'S ANALYSIS OF COMPLAINT AND WARRANTY DATA DETERMINED THAT THE RATE OF ENGINE STALL INCIDENTS RESULTING FROM FUEL PUMP FAILURE IS LOW AT APPROXIMATELY 0.2 PERCENT AFTER THREE YEARS IN SERVICE. ON JANUARY 17, 2006, VW SUBMITTED A DEFECT INFORMATION REPORT TO ODI CONCERNING A SAFETY RECALL TO ADDRESS A DEFECT IN THE FUEL PUMPS OF APPROXIMATELY 74,000 MODEL YEAR (MY) 2003 VOLKSWAGEN PASSAT (47,000), AUDI A4 (20,000) AND AUDI A6 (7,000) VEHICLES BUILT FROM SEPTEMBER 2002 THROUGH MARCH 2003 (NHTSA RECALL NO. 06V-017, VW RECALL NOS. M7 FOR PASSAT AND JL FOR AUDI A4 AND A6).

ACCORDING TO VW, A SUB-SUPPLIER EXPERIENCED AN UNKNOWN CHANGE IN THE MATERIAL COMPOSITION OF THE CARBON-BRUSH SET USED IN THE ELECTRIC MOTOR IN THE FUEL PUMP, WHICH COULD LEAD TO INCREASED WEAR OF THE CARBON-BRUSH SETS, WHICH IN TURN CAN LEAD TO AN INOPERATIVE FUEL PUMP AND, ULTIMATELY, STOPPAGE OF FUEL SUPPLY TO THE ENGINE.ON JULY 23, 2007, VW EXPANDED THE SCOPE OF THE RECALL TO INCLUDE VEHICLES MANUFACTURED FROM AUGUST 2002 THROUGH APRIL 2003, ADDING ANOTHER 34,358 VEHICLES TO THE ORIGINAL RECALL (24,801 VOLKSWAGEN PASSAT, 7,436 AUDI A4 AND 2,121 AUDI A6 VEHICLES).

ODI ASSIGNED RECALL NO. 07V-375 TO THE AMENDED RECALL REPORT. THE MY 2004 AUDI A4 VEHICLES THAT ARE THE SUBJECT OF PE08-027 ARE NOT AFFECTED BY THE SUB-SUPPLIER ISSUE THAT PROMPTED 06V-017 AND 07V-375.

PRODUCTION OF THE MY 2004 VEHICLES BEGAN FOUR MONTHS AFTER THE AMENDED PRODUCTION RANGE IDENTIFIED IN 07V-375.

THE FUEL PUMP FAILURES IN THE MY 2004 VEHICLES HAVE DIFFERENT CAUSES THAN THE DEFECT IDENTIFIED IN THE PRIOR RECALL POPULATIONS AND HAVE OCCURRED AT MUCH LOWER FREQUENCIES. FURTHER INVESTIGATION OF THIS MATTER WOULD NOT BE AN EFFICIENT ALLOCATION OF AGENCY RESOURCES.ACCORDINGLY, THIS INVESTIGATION IS CLOSED.THE CLOSING OF THIS INVESTIGATION DOES NOT CONSTITUTE A FIND BY NHTSA THAT A SAFETY-RELATED DEFECT DOES NOT EXIST.THE AGENCY WILL CONTINUE TO MONITOR COMPLAINTS AND OTHER INFORMATION RELATING TO THE ALLEGED DEFECT IN THE SUBJECT VEHICLES AND TAKE FURTHER ACTION IN THE FUTURE IF WARRANTED.