Tachometer Inaccurate or Inoperative. Chevrolet Cobalt 2007

For 1990-2009 cars only

Makes 🢒 Chevrolet 🢒 2007 🢒 Cobalt 🢒 Diagnostic Navigation 🢒 Vehicle Diagnostic Information 🢒 Tachometer Inaccurate or Inoperative

Diagnostic Instructions

•	Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure

•	Review Strategy Based Diagnosis for an overview of the diagnostic approach

•	Diagnostic Procedure Instructions provides an overview of each diagnostic category

The instrument panel cluster (IPC) displays the engine speed based on the engine speed data from the body control module (BCM). The ECM sends the engine speed signal information via the serial data circuit to the BCM. The BCM sends a serial data message to the IPC indicating the engine speed. The IPC displays the engine speed based on the serial data message from the BCM.

Reference Information

Schematic Reference

•	Instrument Cluster Schematics

•	Engine Controls Schematics for the 2.0L engine

•	Engine Controls Schematics for the 2.2L engine

•	Engine Controls Schematics for the 2.4L engine

Connector End View Reference

•	Displays and Gages Connector End Views

•	Powertrain Control Module Connector End Views for the 2.0L engine

•	Engine Control Module Connector End Views for the 2.2L engine

•	Engine Control Module Connector End Views for the 2.4L engine

Electrical Information Reference

•	Circuit Testing

•	Connector Repairs

•	Testing for Intermittent Conditions and Poor Connections

•	Wiring Repairs

Scan Tool Reference

Scan Tool Data List

Circuit/System Testing

Ignition ON, with the scan tool, perform the IPC Gage Sweep Test in the IPC Output Controls. Verify that all gage dials move from minimum to the maximum value and back to the gage minimum value.

⇒	If the tachometer does not perform the IPC Gage Sweep Test, replace the IPC.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Control Module References for IPC replacement, setup, and programming