Tachometer

The tachometer displays engine RPM (speed), between 0 and 7000 RPM, anytime the power mode is RUN. The engine RPM is calculated by a discrete signal sent to the IPC from the PCM. The engine speed signal is active low, with a pull-up resistor located in the IPC and connected to switched battery voltage. The signal is a square wave with a 25 to 75 percent duty cycle. Each engine revolution is represented by two input pulses. Engine speed is calculated using the time difference between the two consecutive pulses. Accuracy of the final calculations are within 25 RPM.

The tachometer for the analog (UY9) instrument cluster is a gauge. The tachometer for the digital (U02) instrument cluster is part of the Driver Information Center (DIC) and is displays as one of the vehicle display parameters.

For a description of the RPO Code(s) shown in this image/article refer to the RPO Code List found at Vehicle/Application ID RPO Codes