Theory Of Operation
WARNING: This page is about a different car, the 2009 Dodge Caliber. However, it is still accessible from the selected car via links, so may be relevant.
An estimated turbo rotational speed is calculated based on the throttle inlet pressure and the amount of air flowing through the engine. If the estimated turbo rotational speed is above 170,000 RPM, a pending fault is set. If the fault sets again within 3 key cycles, the MIL is illuminated. If three ignition key cycles are accumulated without an additional failure, the pending fault is cleared.