Perform the Diagnostic System Check - Vehicle , prior to using this diagnostic procedure.
The instrument panel cluster (IPC) displays the engine speed based on information received from the engine control module (ECM). The ECM sends the engine speed information via high speed GMLAN serial data circuit to the body control module (BCM). The BCM then sends the information via low speed GMLAN to the IPC to order to display the engine speed.
Instrument Cluster Schematics .
⇒ | If the tachometer gage does not sweep from its low to high position, replace the instrument panel cluster (IPC). |
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
Control Module References for IPC replacement, setup and programming.