The Bradley Combat Vehicle Motor Chatter case study focuses on one aspect of a combat vehicle program, specifically, responding to a vehicle production situation where combat vehicles produced with in-spec components and subsystems exhibit out-of-spec and failing system behavior. This typically results in an extended production line-down or line-degraded situation lasting for several quarters until the problem can be diagnosed, fixed, validated and verified. Subsequently, adequate quantities of the modified or replaced sub-systems must be put back into the production flow. The direct and indirect costs of an occurrence like this in peace-time are measured in the 10’s to 100’s of Millions of dollars. The schedule, program and perception impact to the vehicle platform can be potentially devastating. In war-time all of these impacts are magnified greatly by the added risk to soldiers’ lives. This paper describes the Bradley Combat Vehicle Motor Chatter case study and the revolutionary tools and systems engineering approach utilized by CPU Tech and BAE Systems that determined the root cause, verified and validated the fix, and implemented the fix without impact to the Bradley Combat Vehicle production. CPU Tech utilized a unique real-time nonintrusive (RTNI) diagnostics and configuration port built into the TDCUII LRU and a full vehicle, real-time Bradley Model developed for the SystemLab PS® Virtual Systems Integration Lab (VSIL) to diagnose, replicate and fix the problem on the production Bradley Combat Vehicles in York, PA and work with BAE Systems and the Army to validate and verify the solution in Yuma, AZ. CPU Tech and BAE Systems were able to upgrade 150 production Bradley Combat Vehicles in 4 days using the RTNI port, an Ethernet cable and a laptop without removing a single LRU.