SRX RWD V8-4.6L VIN A (2006)
Tachometer: Description and Operation
TACHOMETER
The instrument panel cluster (IPC) receives a discrete input from the engine control module (ECM) indicating vehicle speed. Each engine revolution is
represents 2 input pulses to the ECM. The instantaneous engine speed is calculated by the ECM using the time difference between the 2 input pulses. The
tachometer will default to 0 RPM if:
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The ignition is in OFF, ACCESSORY, or CRANK.
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The time duration since the last pulse is greater than or equal to 1 second.
