DeVille V8-4.6L VIN Y (1998)
Driver/Vehicle Information Display: Description and Operation
ENGINE RPM (Digital)
The engine RPM parameter is displayed by pressing the INFORMATION (digital) button until the ENGINE RPM message is displayed. The IPC
contains the engine RPM data via CKT 121 (WHT) from the PCM. The engine speed (RPM) parameter is calculated from the time difference between
two consecutive tachometer pulses. This message may be suppressed by using the override option E. Refer to A Diagnostic System Check - Instrument
Cluster. The engine RPM parameter displays dashes if a malfunction occurs in the serial data communications from the IPC to the PCM. Diagnose this
symptom by retrieving and diagnosing the IPC or PCM serial data communication DTCs.