2001 Chevrolet Yukon problems

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 the federal safety agency 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 the federal safety agency that a safety-related defect does not exist.The agency will monitor t

EA11001

In a letter dated november 7, 2007, general motors (gm) reported to the office of defects investigation (odi) that it will conduct a safety recall (07v‑521) to replace the crank position sensor (ckp) in approximately 12,000 model year (my) 2001 chevrolet silverado and gmc sierra vehicles equipped with 8.1 liter engines manufactured on or before november 15, 2000.according to gm, the ckp can fail intermittently or permanently.a permanent ckp failure would result in an engine stall without restart.an intermittent ckp failure could cause the service engine soon light to illuminate, the vehicle to run rough or the engine to stall but allows restart.as a remedy, an improved ckp will be installed in the subject vehicles.the recall campaign will start in december 2007. During the preliminary evaluation (pe06-016), and this ea investigation, gm and odi independently conducted detailed reviews of certain field data to understand the nature and rate of subject vehicle stalling due to ckp failures.gm and odi reviewed gm's warranty claims for the ckp with the objective of ascertaining an estimate of those claims representing an engine stall while driving.the ckp warranty claims without verbatim text were the largest segment of warranty claims.using those claims, gm surveyed vehicle owners to gather additional information to determine if the claim was associated with a stall while driving event.based on the survey, gm estimated that approximately 49% of all warranty repairs for the ckp involved a stall while driving.odi?s review of gm's survey data produced a higher estimate (71%) for stall while driving.gm further estimated the rate of stall while driving for the subject vehicles over time.it estimated stalling while driving rates of 1.6%, 4.6% and 8.9% at 1, 3 and 6 years in service respectively.odi's review of the gm's survey data finds higher estimated stall while driving rates of 2.2%, 6.8% and 13% at 1, 3 and 6 years in service respectively. Odi also conducted a survey of vehicle owners using consumer complaints reported to both odi and gm.the objective was to ascertain the potential safety consequences of an engine stall due to the alleged defect.with respect to the ability to restart the vehicle after a stall, 11% reported immediate restart, 69% reported delayed restart and 20% reported no restart.over half noted at least one engine stall incident at speeds in excess of 40mph. About one-third noted the vehicle was stranded either partially or fully in a lane of traffic after the engine stall.all of the consumers surveyed noted multiple stalling events prior to proper diagnosis and replacement of the ckp.based on gm's decision to conduct a safety recall, this investigation is closed.

EA06016

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.

DP05009

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.

EA04012

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 the federal safety agency that no safety-related defect exists.the agency will take further action if warranted by the circumstances.

PE03026