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NHTSA Office of Defects Investigation

Engineering Analysis EA02-015: THROTTLE STICKING CLOSED

  • Closed

NHTSA's Office of Defects Investigation opened Engineering Analysis EA02-015 on August 1, 2002 and closed it on January 12, 2004. NHTSA's investigations file lists 8 models from 3 makes for it.

Updated daily from NHTSA's investigations file

Key facts

NHTSA number
EA02-015 (also written EA02015)
Investigation type
Engineering Analysis A more detailed stage of a defect investigation, opened when NHTSA's Office of Defects Investigation decides an issue merits further review, often after a Preliminary Evaluation or a Recall Query; it can include vehicle testing, surveys and further information requests.
Status
Closed January 12, 2004
Opened
Closed
Vehicle or equipment manufacturer
General Motors, LLC
Component
Vehicle Speed Control — Linkages
Vehicles and equipment
8 models from 3 makes, including the Cadillac Escalade and Chevrolet Avalanche

A recall appears here only when NHTSA's investigations file links one to the investigation; NHTSA's summary or record can name others.

NHTSA's summary

As NHTSA's Office of Defects Investigation wrote it for Engineering Analysis EA02-015.

try.vin does not copy NHTSA's investigation documents; NHTSA's investigation record lists the ones NHTSA has published.

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.

Vehicles and equipment listed for this investigation

NHTSA's investigations file lists these vehicles and equipment for Engineering Analysis EA02-015. A listed model year means only that an investigation names it; it says nothing about any particular vehicle. Model years with a try.vin recall page link to that page's NHTSA investigations section.

Cadillac

All Cadillac recalls

Chevrolet

All Chevrolet recalls

GMC

All GMC recalls

What an NHTSA investigation is

NHTSA's Office of Defects Investigation (ODI) looks into possible safety defects in vehicles and equipment, often after owner complaints. An investigation usually starts as a Preliminary Evaluation, or as a Recall Query when it concerns whether an existing recall covers the right vehicles or fixes the problem, and ODI can upgrade it to a more detailed Engineering Analysis. A Defect Petition asks NHTSA to open an investigation, and Audit and Equipment Queries are administrative investigations into whether companies complied with federal vehicle safety requirements, such as reporting, recall and certification rules.

An open investigation is not a finding that a safety defect exists, and NHTSA can close one without a recall.

To see whether a specific vehicle has an open recall, enter its VIN at nhtsa.gov/recalls.

Free VIN check: decode a VIN to see its year, make and model.

Sources

NHTSA's investigation record for EA02-015

Investigation details come from NHTSA's investigations file, which try.vin imports once a day. The investigation types are described from the U.S. Department of Transportation Inspector General's May 2023 report on NHTSA's Office of Defects Investigation, NHTSA's petition rules (49 CFR Parts 552 and 557) and NHTSA's Office of Defects Investigation procedures. How try.vin reads NHTSA investigations.