Citation

Nagel A. Collision 2008; 3(2): 22-35.

Copyright

(Copyright © 2008, Collision Publishing)

DOI

unavailable

PMID

unavailable

Abstract

The accuracy of precrash vehicle speed values recorded by event data recorders (EDRs) depends on having the correct internal vehicle speed sensor calibration settings within the powertrain control module (PCM). The values are accurately calibrated if variables such as tire size and axle ratios are unchanged from when the vehicle was produced at the factory. However, aftermarket products and reprogramming tools make it possible for the end user to alter the vehicle speed calibration within the PCM. This article provides a suggested protocol to identify and compensate for these potential errors in the recorded precrash vehicle speeds as stored in the EDR event file. Recognizing and adjusting for this phenomenon will allow accident investigators to continue to rely on the accuracy of EDR data.