2001 Chevrolet
SUBURBANProblems & recalls

On January 11, 2011, ODI opened EA11-001 to investigate allegations of premature brake line corrosion failure in model year (MY) 1999 through 2003 General Motors (GM) full-size pickup trucks and sport utility vehicles sold or registered in the following region of the United States that NHTSA has viewed as salt states for investigations of corrosion related issues:Connecticut, Delaware, District of Columbia, Illinois, Indiana, Iowa, Maine, Maryland, Massachusetts, Michigan, Minnesota, Missouri, New Hampshire, New Jersey, New York, Ohio, Pennsylvania, Rhode Island, Vermont, West Virginia and Wisconsin.The subject vehicles represent the first five MY's of GM's GMT800 platform production, of which approximately 2,038,504 vehicles were sold in salt states (the subject vehicles).The GMT800 platform includes the following vehicles:1999-2007 Chevrolet Silverado and GMC Sierra 1500, 2500 and 3500 series pick-up trucks; 2000-2006 Chevrolet Suburban, Chevrolet Tahoe and GMC Yukon sport utility vehicles; and 2002-2006 Cadillac Escalade and Chevrolet Avalanche sport-utility vehicles.General Motors produced a total of approximately 10,427,062 GMT800 vehicles for sales in the United States, including almost 5 million that were sold in salt states.Although there are over 60 different brake pipe routing configuration used in GMT800 vehicles, with the exception of the rear crossover pipes in MY 200x-2007 vehicles that changed from rear disc to drum brakes, all of the vehicles use brake pipes from the same supplier with a common double-wall, brazed steel pipe design with a combination of hot dip Zinc-Aluminum corrosion protection coating and Aluminum paint outer layer known in the industry as AlGal (ASTM-B750). ODI analysis of field data regarding GMT800 vehicles identified a total of 3,645 complaints of brake pipe corrosion failures, including 107 alleging crashes, and 40 injuries.Though only 20% of total GMT800 production, due to age and region the subject vehicles account for a disproportionate share of the failure experience; with 2,702 of the complaints (75%), 88 of the crashes (82%) and 20 of the injuries (50%) reported in those vehicles.Analysis of the complaints showed strong correlations to vehicle age and region.For vehicles with less than 8 years of service, the complaint rates were minimal for all regions.In the salt states the failure rates begin to climb as the vehicles advance in age, particularly in the Northeast corner of the United States.The complaint rates in the salt states go from less than 0.1 incident per thousand vehicles (IPTV) at 7 years in service to over 1.0 IPTV after the 12th year of service for the subject pickup trucks and utility vehicles.Most of the failures reported to ODI occurred in vehicles with more than 10 years in service.ODI?s investigation did not identify any specific defect conditions that were causing or contributing to the brake pipe failures.Nor did the analysis isolate the problem to any subject vehicle sub-populations when analyzed by vehicle type or production range.The investigation found that vehicles experiencing brake pipe corrosion failures were likely to have general patterns of excessive corrosion on the majority of the brake pipe assembly and appear to be occurring due to expected wear out for the brake pipe coating material used in the subject vehicles and the environmental conditions in severe corrosion states.A safety-related defect has not been identified at this time.Accordingly, this investigation is closed.The closing of this investigation does not constitute a finding by NHTSA that a safety-related defect does not exist.The agency will monitor t

Recorded closure: Apr 8, 2015

The Office of Defects Investigation (ODI) received Defect Petition DP10-003 on March 2, 2010, requesting the investigation of model year (MY) 2003 Chevrolet Silverado 2500HD 4WD pickup trucks for corrosion failures of the vehicle brake lines.DP10-003 was granted and on March 30, 2010, Preliminary Evaluation PE10-010 was opened on more than six million model year 1999 through 2003 light trucks and sport utility vehicles manufactured and sold by General Motors Corporation (GM).On July 2, 2010, ODI received GM's response to an information request, which included GM's assessment of the frequency and safety consequences of the alleged defect. GM stated that:(1) the brake system of the subject vehicles is split front/rear and should a brake pipe suddenly fail for any reason, the affected vehicle would be capable of stopping with the pressure supplied by the remaining circuit; (2) the subject vehicles were designed to meet the hydraulic circuit partial failure requirements of Federal Motor Vehicle Safety Standards 105 and 135, Light Vehicle Brake Systems; and (3) should a brake fluid leak occur for any reason, the brake system malfunction indicator lamp (MIL) would illuminate and warn the driver before the brake fluid level was low enough to cause a loss of line pressure.ODI's and GM's analysis indicates that 85 percent of the complaints occurred on vehicles used primarily in States that use salt on the roads during Winter months (Connecticut, Delaware, District of Columbia, Illinois, Indiana, Iowa, Maine, Maryland, Massachusetts, Michigan, Minnesota, Missouri, New Hampshire, New Jersey, New York, Ohio, Pennsylvania, Rhode Island, Vermont, West Virginia and Wisconsin).Overall the complaint rates per 100,000 vehicles for Salt Belt States is 43.0 and Non-Salt Belt is 3.0.In approximately 25 percent of the complaints the brake pipe failure occurred suddenly, with no warning (i.e., no MIL, Brake Fluid Loss Warning), and resulted in extended stopping distances.In 30 of these the increase in stopping distance that resulted was a factor in the crash and in 10 others the vehicle was intentionally steered off the road or into another lane of travel in order to avoid a crash.This investigation has been upgraded to an Engineering Analysis (EA11-001) for subject vehicles sold or currently registered in Salt Belt States to further assess the scope, frequency and safety risks associated with sudden failures of corroded brake pipes that can result in decreased brake effectiveness. ODI will continue to gather information on subject vehicles outside the Salt Belt as well.

Recorded closure: Jan 5, 2011

THE OFFICE OF DEFECTS INVESTIGATION (ODI) OPENED A PRELIMINARY EVALUATION (PE06-016) ON MAY 4, 2006 BASED ON ELEVEN VEHICLE OWNER QUESTIONNAIRES (VOQS) AND EARLY WARNING (EWR) DATA ALLEGING SUDDEN ENGINE SHUTDOWN WHILE DRIVING AS A RESULT OF CRANK POSITION SENSOR FAILURES IN MY 2001-2002 GENERAL MOTORS C/K PLATFORM VEHICLES EQUIPPED WITH 8.1L ENGINES.IN RESPONSE TO AN INFORMATION REQUEST LETTER SENT BY ODI, GENERAL MOTORS (GM) PROVIDED OWNER COMPLAINT INFORMATION, FIELD REPORTS AND WARRANTY CLAIM DATA BASED ON A POPULATION OF 108,338 VEHICLES. THE DATA WAS CATEGORIZED BY ENGINE STALLS WHILE DRIVING, ENGINE STALLS WITH AN UNKNOWN DRIVING CONDITION, NO START CONDITIONS AND CLAIMS WHERE IT WAS INDETERMINATE IF AN ENGINE STALL OCCURRED WHILE DRIVING.GENERAL MOTOR'S RESPONSE INCLUDED 1,213 OWNER COMPLAINTS AND FIELD REPORTS OF WHICH 289 WERE CATEGORIZED AS ENGINE STALLS WHILE DRIVING ALLEGEDLY CAUSED BY CRANK POSITION SENSOR FAILURES. GENERAL MOTORS ALSO SUBMITTED WARRANTY CLAIMS FROM ITS REGULAR WARRANTY (5 YEARS/50,000 MILES) AND FROM ITS EXTENDED WARRANTY DATABASE. FROM THE REGULAR WARRANTY DATABASE THERE WERE 3,140 CLAIMS OF CRANK POSITION SENSOR REPLACEMENT OF WHICH 147 CLAIMS WERE FROM CONSUMERS ALLEGING ENGINE STALL WHILE DRIVING.GM STATED THAT 2,841 OF THE CLAIMS WERE INDETERMINATE IF AN ENGINE STALL OCCURRED WHILE DRIVING.FROM ITS EXTENDED WARRANTY DATABASE, GM SUBMITTED 1,561 CLAIMS OF CRANK POSITION SENSOR FAILURE THAT IT ALSO STATED WERE INDETERMINATE AS TO WHETHER AN ENGINE STALL OCCURRED WHILE DRIVING.IN TOTAL, GM REPORTS 4,701 CLAIMS OF CRANK POSITION SENSOR FAILURE COMBINING REGULAR WARRANTY AND EXTENDED WARRANTY.SIMILAR TO GM'S STATISTICAL ANALYSIS, ODI'S ANALYSIS SHOWED THAT THE FAILURE RATE FOR WARRANTY CLAIMS OF ENGINE STALL WHILE DRIVING AT THREE YEARS IN SERVICE IS LOW (LESS THAN 1%).HOWEVER, FURTHER ANALYSIS DETERMINED THAT THE MY 2001 VEHICLE BUILD PERIOD FROM MAY 2000 THROUGH OCTOBER 2000 HAD SIGNIFICANTLY HIGHER (MORE THAN FOUR TIMES) CRANK POSITION FAILURE RATES IN BOTH CONSUMER COMPLAINT DATA AND WARRANTY CLAIM DATA THAN IN THE BUILD PERIOD FROM NOVEMBER 2000 THROUGH JULY 2001.ADDING THE CLAIMS OF KNOWN ENGINE STALL WHILE DRIVING AND CLAIMS WHERE ENGINE STALL WAS INDETERMINATE, THE FAILURE RATE AT THREE YEARS IN SERVICE FOR THIS POPULATION IS OVER 6%.AN ENGINEERING ANALYSIS (EA06-016) HAS BEEN OPENED TO FURTHER ASSESS THE FREQUENCY AND POTENTIAL SAFETY CONSEQUENCES ASSOCIATED WITH THE ALLEGED DEFECT IN VEHICLES BUILT FROM MAY 2000 THROUGH OCTOBER 2000.

Recorded closure: Sep 14, 2006

ODI'S REVIEW OF COMPLAINT DATA RECEIVED SINCE THE CLOSE OF EA04-011 REVEALED NO INDICATION THAT THE INVESTIGATION SHOULD BE RE-OPENED.MORE DETAILS CAN BE FOUND IN THE FEDERAL REGISTER NOTICE ENCLOSED IN THE DP05-009 PUBLIC FILE.ODI RESERVES THE RIGHT TO REOPEN THE INVESTIGATION IN THE FUTURE SHOULD CONDITIONS WARRANT.

Recorded closure: May 31, 2006

IN A LETTER DATED AUGUST 29, 2005, GM NOTIFIED ODI THAT IT WAS RECALLING CERTAIN MODEL YEAR 1999 THROUGH 2002 C/K PICKUP TRUCKS AND SPORT UTILITY VEHICLES TO CORRECT A PROBLEM WITH ANTI-LOCK BRAKE SYSTEM (ABS) WHEEL SPEED SENSOR CORROSION THAT MAY RESULT IN UNWANTED ABS ACTIVATION AND EXTENDED STOPPING DISTANCES DURING LOW-SPEED BRAKING (RECALL 05V-379).GM'S RECALL COVERS APPROXIMATELY 804,000 VEHICLES CURRENTLY REGISTERED IN THE FOLLOWING 14 SALT-BELT STATES:CONNECTICUT, ILLINOIS, INDIANA, MASSACHUSETTS, MAINE, MICHIGAN, NEW HAMPSHIRE, NEW JERSEY, NEW YORK, OHIO, PENNSYLVANIA, RHODE ISLAND, VERMONT, AND WEST VIRGINIA.THE RECALL PROCEDURE WILL INVOLVE REMOVING THE SENSOR, CLEANING THE MOUNTING SURFACE, APPLYING A RUST INHIBITOR (ZINC-X) TO THE SURFACE, AND REINSTALLING THE SENSOR.IF NECESSARY, THE SENSOR WILL BE REPLACED. THE POPULATION AND FAILURE REPORT DATA GIVEN IN THIS RESUME ARE FOR THE FULL REGION THAT HAS BEEN CONSIDERED BY ODI AS THE SALT-BELT.THAT INCLUDES DELAWARE, IOWA, MARYLAND, MINNESOTA, MISSOURI, WISCONSIN AND THE DISTRICT OF COLUMBIA IN ADDITION TO THE 14 STATES INCLUDED IN 05V-379.THE STATES COVERED BY GM'S RECALL HAVE THE HIGHEST INCIDENT RATES FOR THE SUBJECT CONDITION, ACCOUNTING FOR 91% OF THE INCIDENTS, BUT ONLY 24% OF SUBJECT VEHICLE SALES IN THE UNITED STATES.ODI'S ANALYSIS DETERMINED THAT 840 OF THE COMPLAINTS, 244 OF THE CRASHES, AND 16 OF THE INJURIES IDENTIFIED IN THIS INVESTIGATION OCCURRED IN THOSE STATES.THE RESULTING INCIDENT AND CRASH RATES ARE 96.2 AND 28.0 PER 100,000 VEHICLES RESPECTIVELY (NOTE:RATES ARE BASED ON VEHICLE SALES, NOT REGISTERED VEHICLES). THE CORRESPONDING NUMBERS IN THE EXCLUDED PORTIONS OF THE SALT-BELT ARE 399,000 VEHICLES, 81 INCIDENTS (20.3 PER 100,000 VEHICLES), 3 CRASHES, AND NO INJURIES.THE STATISTICS IN THE REMAINING 30 STATES ARE 2,406,000 VEHICLES, 168 INCIDENTS (7.0 PER 100,000 VEHICLES), 31 CRASHES, AND ONE INJURY.GM AND ODI ARE CONTINUING TO MONITOR THE PROBLEM EXPERIENCE IN STATES THAT ARE NOT INCLUDED IN THE RECALL.GM WILL PROVIDE ODI WITH UPDATED COMPLAINT, FIELD REPORT, AND WARRANTY DATA IN NOVEMBER 2005.ODI AND GM WILL REVIEW THAT DATA AND ASSESS THE APPROPRIATENESS OF THE CURRENT SCOPE OF THE RECALL AT THAT TIME.

Recorded closure: Sep 13, 2005

Campaign reference in the source: 05V379000

IN A LETTER DATED APRIL 14, 2005, GENERAL MOTORS (GM) NOTIFIED ODI THAT IT HAD IDENTIFIED A DEFECT RELATED TO MOTOR VEHICLE SAFETY IN APPROXIMATELY 316,508 MODEL YEAR (MY) 2000-01 1500 SERIES CHEVROLET SUBURBAN AND GMC YUKON XL VEHICLES (RECALL 05V-155).GM DETERMINED THAT SOME OF THESE VEHICLES WERE EQUIPPED WITH FUEL MODULE RESERVOIR ASSEMBLIES (MRAS) THAT CONTAIN FUEL PUMP WIRES AND/OR CONNECTORS THAT MAY OVERHEAT UNDER CERTAIN OPERATING CONDITIONS.ACCORDING TO GM, FUEL PUMP WIRES THAT OVERHEAT MAY RESULT IN ONE OR MORE CONDITIONS THAT PRESENT RISKS TO MOTOR VEHICLE SAFETY:(1) FUEL LEAKAGE FROM THE MRA PASS-THROUGH CONNECTOR IF THE OVERHEATING PRODUCES A HOLE IN THE PLASTIC CONNECTOR; (2) ENGINE STALL IF WIRING EXPOSED BY THE OVERHEATING SHORTS TO GROUND AND CAUSES THE FUEL PUMP FUSE TO BLOW; OR (3) INACCURATE FUEL LEVEL READINGS IF OVERHEATED WIRING IS SHORTED TO THE FUEL LEVEL SENDER CARD.GM'S ANALYSIS IDENTIFIED THE CAUSE OF THE OVERHEATED WIRING AS A HIGH-RESISTANCE CONDITION IN THE MRA CONNECTOR CONTACTS DUE TO FRETTING CORROSION THAT MAY DEVELOP OVER TIME.GM DETERMINED THAT THE CORROSION IS CAUSED BY MOVEMENT BETWEEN THE CONTACT SURFACES AND THAT SUCH MOVEMENT IS PRIMARILY INFLUENCED BY CHASSIS AND FUEL TANK VIRBRATION CHARACTERISTICS.GM'S TESTING FOUND THAT THE FUEL TANK VIBRATION CHARACTERISTICS OF THE RECALLED MY 2000-01 1500-SERIES VEHICLES WERE SIGNIFICANTLY GREATER THAN IN OTHER GM VEHICLES EQUIPPED WITH THE SAME MRA CONNECTORS.THESE VEHICLES HAD THE HIGHEST RATE OF RELATED FUEL LEAK AND STALL COMPLAINTS; AND A RECENT SURVEY CONDUCTED BY GM FOUND EVIDENCE OF MRA WIRING OVER-HEATING IN ALMOST ONE-THIRD OF THE 1500-SERIES VEHICLES INSPECTED. OTHER VEHICLES EQUIPPED WITH THE SUBJECT MRA CONNECTOR AND EVALUATED DURING THIS INVESTIGATION INCLUDE APPROXIMATELY 33,000 MY 2000-01 2500-SERIES SUBUBRAN AND YUKON XL VEHICLES, WHICH FALL WITHIN THE SCOPE OF EA04-026, AND PEER POPULATIONS OF SHORT WHEELBASE YUKON AND TAHOE UTILITY VEHICLES AND FULL-SIZE SILVERADO AND SIERRA PICKUP TRUCKS. THESE VEHICLES ARE NOT INCLUDED IN RECALL 05V-155 FOR THE FOLLOWING REASONS:(1) THESE VEHICLES ARE EQUIPPED WITH FUEL TANKS WITH SIGNIFICANTLY LESS VIBRATION AT THE MRA INTERFACE THAN THE RECALLED VEHICLES; (2) THE POTENTIAL FOR FUEL LEAKAGE IS SUBSTANTIALLY LOWER IN THE PICKUP TRUCKS AND SHORT-WHEELBASE UTILITY VEHICLES DUE TO DIFFERENCES IN FUEL TANK CONFIGURATION AND NO INCIDENTS OF FUEL LEAKAGE DUE TO OVERHEATED WIRING WERE VERIFIED IN THESE VEHICLES; (3) THERE THERE HAVE BEEN ONLY THREE POTENTIALLY RELATED COMPLAINTS OF FUEL LEAKAGE ASSOCIATED WITH THE OVERHEATED WIRING CONDITION IN THE 2500-SERIES LONG-WHEELBASE UTILITY VEHICLES; AND (4) NO EVIDENCE OF OVERHEATED WIRING WAS FOUND IN THE 2500-SERIES SUBURBAN AND YUKON XL VEHICLES AND PICKUP TRUCKS INSPECTED BY GM IN ITS VEHICLE SURVEY EFFORTS AND THE RATE FOUND IN THE SHORT-WHEELBASE UTILITIES WAS LOWER THAN THE RECALLED VEHICLES BY AN ORDER OF MAGNITUDE. ODI WILL CONTINUE TO MONITOR THE EXPERIENCE IN THE 2500 SERIES MY 2000-01 LONG-WHEELBASE UTILITY VEHICLES.THE CLOSING OF THIS INVESTIGATION DOES NOT CONSTITUTE A FINDING BY NHTSA THAT NO SAFETY-RELATED DEFECT EXISTS FOR THE 2500 SERIES VEHICLES.THE AGENCY RESERVES THE RIGHT TO TAKE FURTHER ACTION IF WARRANTED BY A CHANGE IN CIRCUMSTANCES.

Recorded closure: Aug 2, 2005

Campaign reference in the source: 05V155000

THE FUEL PUMP WIRING AND CONNECTOR MAY OVERHEAT AND MELT A HOLE IN THE TOP OF THE FUEL PUMP MODULE.POSSIBLE CONSEQUENCES INCLUDE FUEL TANK LEAKAGE AND ENGINE STALL WITH NO RESTART.FOURTEEN OF THE 20 COMPLAINTS TO ODI ALLEGE FUEL TANK LEAKAGE, INCLUDING ONE THAT REPORTED THAT A FIRE DEPARTMENT WAS CALLED TO THE SCENE AFTER A POOL OF GASOLINE WAS DISCOVERED BENEATH THE VEHICLE.MOST OF THE ODI COMPLAINTS REPORT INCIDENTS THAT OCCURRED WITHIN THE PAST YEAR. ACCORDING TO GM, FUEL LEAKAGE CAN OCCUR IN THE SUBJECT VEHICLES IF THE HEAT IS SUFFICIENT TO MELT A HOLE IN THE PLASTIC CONNECTOR LARGE ENOUGH FOR LIQUID FUEL TO FLOW THROUGH.ON-BOARD EMISSIONS DIAGNOSTICS MAY DETECT HOLES THAT ARE APPROXIMATELY 0.040 INCHES OR MORE AND SET A SERVICE ENGINE SOON WARNING LIGHT.THE CONNECTOR POSITION IN THE SUBJECT VEHICLES IS BELOW THE FUEL LEVEL WHEN THE TANK IS FULL.WHILE GM DOES NOT KNOW HOW MUCH FUEL COULD LEAK FROM A TANK WITH A MELTED FUEL PUMP CONNECTOR, SEVERAL CONSUMERS HAVE REPORTED SIGNIFICANT LEAK EVENTS.ENGINE STALL CAN OCCUR IF:(1) A SHORT OCCURS IN THE PUMP WIRING (BARE WIRE EXPOSED BY MELTED INSULATION SHORTS AGAINST A GROUND OR GROUND WIRE) AND THE FUEL PUMP RELAY FUSE IS BLOWN; OR (2) THE VEHICLE RUNS OUT OF FUEL DUE TO AN INACCURATE FUEL GAUGE READING RESULTING FROM AN ELECTRICAL SHORT BETWEEN THE FUEL PUMP WIRING AND THE LEVEL SENSOR WIRING. GM'S ANALYSIS OF FIVE ASSEMBLIES RETURNED FROM INCIDENT VEHICLES DETERMINED THAT THE CONDITION IS CAUSED BY ELEVATED RESISTANCE/ ARCING AT THE MRA UNDERCOVER B CAVITY TERMINAL OF THE FOUR-WAY 150 METRI-PAK CONNECTOR.GM ATTRIBUTES THE HIGH RESISTANCE AND ARCING TO A DEPRESSED CONTACT ARM AT THE 150 METRI-PAK B CAVITY FEMALE TERMINAL.GM IS CONTINUING ITS INVESTIGATION TO COMPLETE ITS ROOT CAUSE ANALYSIS. MODULAR RESERVOIR ASSEMBLIES USING THE 150 METRI-PAK CONNECTORS WERE USED BY GM IN SEVERAL MILLION C/K-SERIES SPORT UTILITY VEHICLES AND PICKUP TRUCKS FROM MY 1997 THROUGH 2002, WHEN GM RELEASED A METAL MRA COVER AND A 280 METRI-PAK CONNECTOR IN THE SUBJECT VEHICLES.DURING PE04-042, ODI COLLECTED INFORMATION FROM GM CONCERNING MY 2000-2002 C/K SUV'S AND PICKUP TRUCKS.THE SUBJECT VEHICLES COMPRISE APPROXIMATELY 9 PERCENT OF PRODUCTION FOR THOSE VEHICLES AND ABOUT 39 PERCENT OF COMPLAINTS TO GM. THIS INVESTIGATION HAS BEEN UPGRADED TO AN ENGINEERING ANALYSIS TO FURTHER ASSESS THE SCOPE, FREQUENCY, AND SAFETY CONSEQUENCES OF THE ALLEGED DEFECT IN GM C/K-SERIES VEHICLES.

Recorded closure: Sep 9, 2004

Campaign reference in the source: 05V155000

GM IS CONDUCTING A RECALL ON ALL SUBJECT VEHICLES BUILD BETWEEN MAY 1999 AND OCTOBER 14, 1999.SIGNIFICANT CHANGES WERE INCORPORATED INTO PRODUCTION IN EARLY OCTOBER 1999, AND VEHICLES BUILT AFTER THAT DATE HAVE LOWER WARRANTY FAILURE RATES.THE COMPLAINT AND WARRANTY DATA APPEAR TO SUPPORT THE EFFECTIVENESS OF THESE CHANGES. GM MADE ADDITIONAL CHANGES IN NOVEMBER 1999, FEBRUARY 2000, MAY 2001, AND FEBRUARY 2004.ODI WILL CONTINUE TO MONITOR THIS PROBLEM AND WILL TAKE FURTHER ACTION, IF WARRANTED, IN THE FUTURE.FOR FURTHER TECHNICAL DETAILS SEE THE ATTACHED ENGINEERING ANALYSIS REPORT.

Recorded closure: Feb 28, 2005

Campaign reference in the source: 05V005000

THERE HAVE BEEN LESS THAN 2 COMPLAINTS PER 100,000 SUBJECT VEHICLES RELATED TO THE ALLEGED DEFECT.THE OLDEST VEHICLES (MY 1999) HAVE ONLY 2 COMPLAINTS IN OVER 140 THOUSAND VEHICLES AFTER OVER 4 YEARS IN SERVICE.THE RATE OF WARRANTY CLAIMS POTENTIALLY RELATED TO THE ALLEGED DEFECT IS LESS THAN 0.1%.THERE ARE NO KNOWN INCIDENTS INVOLVING RAPID LOSS OF TIRE PRESSURE OR LOSS OF VEHICLE CONTROL. A DEFECT TREND HAS NOT BEEN IDENTIFIED AT THIS TIME.ACCORDINGLY, THIS INVESTIGATION IS CLOSED.THE CLOSING OF THIS INVESTIGATION DOES NOT CONSTITUTE A FINDING BY NHTSA THAT NO SAFETY-RELATED DEFECT EXISTS.THE AGENCY WILL TAKE FURTHER ACTION IF WARRANTED BY THE CIRCUMSTANCES.

Recorded closure: Nov 3, 2003

THE AUTOMATIC LOCKING RETRACTOR (ALR) IS A FEATURE INCORPORATED IN THE SUBJECT VEHICLE FOR LOCKING THE WEBBING TO PROPERLY SECURE A CHILD SAFETY SEAT INTO A VEHICLE.THIS PE WAS OPENED BASED ON A GM TECHNICAL SERVICE BULLETIN STATING THAT WITH CERTAIN CHILD SAFETY SEATS THE WEBBING MAY NOT REMAIN LOCKED.THERE ARE NO COMPLAINTS IN THE ODI DATABASE AND ONLY TWO COMPLAINTS TO GM.GM'S INSTRUCTIONS STATE FOR THE FINAL STEP IN USING THE WEBBING LOCK FEATURE TO PUSH AND PULL THE CHILD RESTRAINT TO BE SURE IT IS SECURE. IF THE ALR IS NOT LOCKED, THE USER WOULD BE FULLY AWARE OF THIS CONDITION PRIOR TO COMPLETING PROPER INSTALLATION OF THE CHILD SAFETY SEAT IN THIS VEHICLE.THIS INVESTIGATION DID NOT UNCOVER ANY COMPLAINTS OF THE ALR INADVERTENTLY UNLOCKING WHILE THE VEHICLE IS IN MOTION.THE EMERGENCY LOCKING RETRACTOR (ELR) FEATURE REMAINS AVAILABLE TO LOCK THE RETRACTOR IN A CRASH.A SAFETY-RELATED DEFECT HAS NOT BEEN IDENTIFIED AT THIS TIME AND FURTHER USE OF AGENCY RESOURCES DOES NOT APPEAR TO BE WARRANTED.ACCORDINGLY, THIS INVESTIGATION IS CLOSED.THE CLOSING OF THIS INVESTIGATION DOES NOT CONSTITUTE A FINDING BY NHTSA THAT NO SAFETY-RELATED DEFECT EXISTS.THE AGENCY RESERVES THE RIGHT TO TAKE FURTHER ACTION IF WARRANTED BY THE CIRCUMSTANCES.SEE ATTACHED SUMMARY FOR ADDITIONAL INFORMATION.

Recorded closure: Feb 11, 2003

THIS INVESTIGATION INVOLVES THE GENERAL MOTORS CORPORATION (GM)THROTTLE BODY (TB) UTILIZED IN MODEL YEAR (MY) 1999-2002 SILVERADO, SIERRA, TAHOE, SUBURBAN, AVALANCHE AND YUKON (SUBJECT VEHICLE(S)) WITH 4.8L, 5.3L, AND 6.0L ENGINES. THE TB VALVE MAY INTERMITTENTLY STICK IN A CLOSED POSITION.IN SUCH A SITUATION, AN OPERATOR MAY APPLY ADDITIONAL ACCELERATOR PEDAL FORCE TO INCREASE ENGINE SPEED.THE APPLICATION OF ADDITIONAL ACCELERATOR PEDAL FORCE, TO OPEN A STUCK THROTTLE VALVE, MAY OPEN THE THROTTLE VALVE MORE THAN INTENDED AND, IN TURN, ACCELERATE THE ENGINE AND VEHICLE MORE THAN INTENDED AND REASONABLY EXPECTED BY THE DRIVER.ON AUGUST 1, 2002, THE OFFICE OF DEFECTS INVESTIGATION (ODI), OF THE NATIONAL HIGHWAY TRAFFIC SAFETY ADMINISTRATION (NHTSA), OPENED THIS ENGINEERING ANALYSIS.THE INVESTIGATION REVEALED THAT TWO FACTORS MAY CAUSE THE DEFECT: 1) TB MANUFACTURING PROCESS PROBLEMS; AND 2) ACCUMULATION OF DEPOSITS (A PCV SYSTEM BY-PRODUCT) ON OR AROUND THE TB THROTTLE VALVE AND BORE.ODI CONCLUDES THAT THE TB PERFORMS IN A DEFECTIVE MANNER AFTER ANALYZING GM?S DATA SUBMISSIONS, AND TEST DATA COLLECTED BY THE VEHICLE RESEARCH AND TEST CENTER (VRTC).FIFTY-NINE CRASHES ARE ALLEGED TO HAVE OCCURRED AS A RESULT OF GM?S TB DEFECT.THE MAJORITY OF THE CRASHES INVOLVE A SINGLE VEHICLE, ENGAGING IN A CLOSE QUARTER VEHICLE MANEUVER (OR LOW SPEED), AND CAUSING ONLY MINOR PROPERTY DAMAGE.FOUR OUT OF THE FIFTY-NINE CRASHES INVOLVE INJURY, AND THOSE INJURIES WERE MINOR.ALTHOUGH GM?S TB IS DEFECTIVE, BASED ON THE EVIDENCE GATHERED, ODI HAS FOUND THAT THE ACCELERATOR PEDAL FORCE REQUIRED TO OPEN A STUCK THROTTLE VALVE IS NEGLIGIBLE, AND THE THROTTLE VALVE DOES NOT STICK IN THE OPEN POSITION.THEREFORE THIS ENGINEERING ANALYSIS (EA02-015) WILL BE CLOSED AT THIS TIME.THE CLOSING OF THIS INVESTIGATION DOES NOT CONSTITUTE A FINDING BY NHTSA THAT A SAFETY-RELATED DEFECT DOES NOT EXIST.FOR A DETAILED DISCUSSION OF THE TB COMPONENT AND TESTING, PLEASE SEE THE ATTACHED REPORT.

Recorded closure: Jan 12, 2004