Overspeed Detection Mode
WARNING: This page is about a different car, the 2006 Dodge Sprinter. However, it is still accessible from the selected car via links, so may be relevant.
If the ECM detects engine RPM that exceeds 5200 RPM, the ECM will set a DTC in memory, limit engine RPM to no more than 2500 RPM, and illuminate the MIL until the DTC is cleared.