NHTSA Office of Defects Investigation
Engineering Analysis EA09-006: ELECTRONIC STABILITY CONTROL
- Closed
NHTSA's Office of Defects Investigation opened Engineering Analysis EA09-006 on April 8, 2009 and closed it on May 12, 2010. NHTSA's investigations file lists the 2003 Toyota Sequoia for it and links recall 10V-176 to it.
Updated daily from NHTSA's investigations file
Key facts
- NHTSA number
- EA09-006 (also written EA09006)
- 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 May 12, 2010
- Opened
- Closed
- Vehicle or equipment manufacturer
- Toyota Motor Corporation
- Components
- Electronic Stability Control; Traction Control System
- Recall linked by NHTSA
- 10V-176: VEHICLE STABILITY CONTROL SYSTEM, reported
- Vehicles and equipment
- 2003 Toyota Sequoia
NHTSA's summary
As NHTSA's Office of Defects Investigation wrote it for Engineering Analysis EA09-006.
On April 28, 2010, Toyota Motor North America submitted a Defect Information Report (NHTSA Recall No. 10V-176) to NHTSA describing a problem in the Vehicle Stability Control (VSC) system in approximately 50,000 Model Year (MY) 2003 Toyota Sequoia vehicles.
According to the report the centering position of the Steering Angle Sensor (SAS) in the MY 2003 vehicles may not be stored correctly due to a logic problem with the Skid Control Computer programming.
The VSC system uses the information from the SAS to calculate the driver's intended vehicle direction.
This information is cross referenced to sensors that tell the system which direction the vehicle is actually going and the system will, if it determines a variance indicating the vehicle is in a over-steer or under-steer condition, reduce throttle control and apply braking to make a correction in vehicle direction towards what the system believes is the driver's intended path.
Toyota dealers will replace the Skid Control Electronic Control Unit in recalled vehicles.
Toyota has indicated to NHTSA that it does not believe that inappropriate activations of the VSC system present an unreasonable risk to safety because it believes the activations are rare and tend to occur at low speeds when the vehicle is fully controllable and that the activations do not last more than a few seconds.
Based on interviews with complainants ODI believes that the majority of the inappropriate activations of the VSC system occur when turning at low speeds, such as when a driver is pulling into or across the flow of oncoming traffic.
Complainants report the effect produced by the malfunction of the VSC system is to leave the vehicle without the ability to accelerate up to speed, essentially leaving them creeping along exposed to oncoming traffic, because of the brake activation and reduction of throttle control caused by the VSC system.
Complainants report that the events can last up to 10 seconds and some complaints report that oncoming traffic had to unexpectedly swerve or severely brake to avoid colliding with the malfunctioning Sequoia.
During the VSC event the brake lights of the Sequoia are not illuminated such that the following traffic is without indication that braking is occurring, nor would the following traffic expect the driver to be applying brakes in such a situation.
Several near misses were reported.
There were also reports of the VSC system malfunctioning and applying vehicle braking unexpectedly while traveling at highway speeds.
Some complainants reported experiencing malfunction activations of the VSC at both low and higher speeds.
ODI counted 140 incidents of lower speed inappropriate activations of the VSC system (approximately 10 mph or less - similar to an inappropriate traction control system activation) and 43 incidents of higher speed inappropriate activations of the VSC system (some as high as 60 mph).
These numbers include complainants who experienced both types of failures.
This investigation is closed based on Toyota's recall.
Vehicles and equipment listed for this investigation
NHTSA's investigations file lists these vehicles and equipment for Engineering Analysis EA09-006. 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.
Toyota
Toyota Sequoia
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.
Toyota VIN check: decode a VIN to see its year, make and model.
Sources
NHTSA's investigation record for EA09-006
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.