September 22, 2011 by markarndt
A recent Recall by Daimler Trucks of 2006 to 2012 Freightliner Trucks highlights recent concern regarding inadvertent actuation of Electronic Stability Control (ESC) Systems. Potentially 47,000 units are recalled with Meritor Wabco ESC systemmanufactured since September of 2005. According to the recall summary, “Under certain road and driving conditions, vehicle body roll and road inclination characteristics may adversely affect the slip angle calculation of the Eectronic Stability Control (ESC) system. This might cause the ESC to perceive an over steering situation and therefore apply the outer wheel brake on the front axle until the vehicle is perceived to be stable.” The Meritor Wabco technologies include ESC, Roll Stability Control and trailer stability control. Some of these systems are described in the Meritor literature as being available since 2002.
Interesting that the vehicle based risk to motor vehicle safety (the recall) lists the defect’s consequence as, “If the driver is slow to react during this ESC intervention, the vehicle may deviate from the intended line of travel increasing the risk of a crash.” In other words, the manufacture is saying they are responsible for an unexpected and dangerous external disturbance to the vehicle – presumably a disturbance from no driver input – but the increased risk of a crash occurs if the driver is slow to react??
