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Home >> Lincoln >> 2011 >> MKS EcoBoost >> Repair and Diagnosis (Single Page) >> Electrical >> Gauges >> Information Center - Instrumentation, Message Center, And Warning Chimes >> Diagnosis And Testing >> Instrumentation, Message Center and Warning Chimes >> Pinpoint Tests >> Pinpoint Test I: The Tachometer Is Inoperative >> Normal Operation

Normal Operation

The PCM uses the Crankshaft Position (CKP) sensor to measure the engine rpm. The PCM sends the Instrument Panel Cluster (IPC) the data over the High Speed Controller Area Network (HS-CAN) communication bus to command the tachometer gauge according to the data.

If the engine rpm data is invalid for 5 seconds or less or if the IPC does not receive the engine rpm data for 5 seconds or less, the IPC defaults the tachometer to the last setting, based upon the last known good rpm message. If the IPC does not receive the engine rpm data from the PCM for more than 5 seconds, the IPC sets DTC U0100:00 in continuous memory and defaults the tachometer to 0 rpm. If the engine rpm data is deemed invalid for 5 seconds or more, the IPC sets DTC U0140:68 and defaults the tachometer to 0 rpm.

NOTE: If DTC U0100:00 is set in the IPC, other observable symptoms may be an inoperative speedometer, temperature gauge or odometer.

This pinpoint test is intended to diagnose the following: 

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