Engine Coolant Temperature Indicator Always On

Engine Coolant Temperature Indicator Always On

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. Initial Inspection and Diagnostic Overview
* Review Strategy Based Diagnosis for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions provides an overview of each diagnostic category.

Circuit/System Description

The instrument panel cluster (IPC) illuminates the TEMP indicator when the engine control module (ECM) determines that the coolant temperature is more than 128°C (262°F). The IPC receives a discrete input from the ECM requesting illumination.

The IPC illuminates the TEMP indicator during the display test at the start of each ignition cycle.

Circuit/System Testing

With the engine running within the normal operating temperature range, the engine coolant temperature (ECT) indicator should not be illuminated.

If the engine coolant is not within the normal operating range, repair the overheating condition.
If the engine coolant is within the normal operating range, replace the IPC.

Repair Instructions

* Engine Overheating
* Instrument Cluster Replacement (Impala) Instrument Cluster Replacement (Monte Carlo)

Repair Verification

Verify that the ECT indicator is OFF while the engine is operating.