System Operation: Gauges: Tachometer
WARNING: This page is about a different car, the 2018 Lincoln MKC. However, it is still accessible from the selected car via links, so may be relevant.
The tachometer is a virtual gauge. The IPC receives the engine rpm data message from the GWM over the HS-CAN3. The GWM receives the engine rpm data message from the PCM over the HS-CAN1.