While semi-active suspension systems have been shown to be effective in the real-time optimization of vehicle ride and handling, these systems also present a means for system interrogation and damage detection. This research demonstrates the ability to monitor the condition of a ground vehicle by utilizing a passively tunable suspension system to systematically alter the suspension parameters in order to probe the system response. By modulating the suspension parameters at a particular corner of the vehicle, or combinations of corners, selected operational modes of the sprung and unsprung masses can be probed providing an increased ability to detect and locate damage in certain vehicle components. The experimental data presented demonstrates that the ability to detect damage was increased by 16.3% and 22.5% for the two simulated damage conditions using the suspension probing technique. A major benefit of the active probing method described in this paper is that the associated damage index is based only on one specific vehicle's response over time. A massive database of historical data from similar vehicles is not required. The active probing method also benefits from transducers already integrated for the control of a typical semi-active suspension system. The benefits of an on-board health monitoring system can be realized with minimal added cost, by adding only a small number of additional sensors. The ability to detect vehicle damage during operation can be extremely advantageous in terms of safety and condition-based maintenance.© (2011) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.