Tachometer Inaccurate or Inoperative

Tachometer Inaccurate or Inoperative

Diagnostic Fault Information

Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. Initial Inspection and Diagnostic Overview


Circuit/System Description

The instrument panel cluster (IPC) displays the engine speed based on the information from the engine control module (ECM). The ECM converts the data from the engine speed sensor to a 2 pulses/engine revolution signal. The ECM sends the engine speed information via class 2 serial data circuit to the IPC in order to display the engine speed.

Circuit/System Testing

Ignition ON, perform the tachometer gage sweep test with the scan tool.

If the tachometer gage does not sweep from its low to high position, replace the IPC.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure. Verification Tests

Programming and Relearning for IPC setup, and programming. Programming and Relearning