Hybrid Electronic Cluster Self-Diagnostics Modes: "tAc"
WARNING: This page is about a different car, the 2002 Ford Pickup. However, it is still accessible from the selected car via links, so may be relevant.
Displays tachometer value input to instrument cluster. Tachometer will indicate present engine speed. Display will indicate zero if input is not received, if input is invalid for more than one second or if actual engine speed is zero.