Low Engine Coolant Indicator Always On

Low Engine Coolant Indicator Always On

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.



Diagnostic Fault Information






Circuit/System Description

The low engine coolant level indicator is controlled by the engine control module (ECM). The normal state of the engine coolant level switch is closed when in contact with coolant.


Diagnostic Aids

When the low coolant indicator comes on, the engine shutdown warning light and audio alarm will also come on. When the engine shutdown warning light comes on with the audio alarm, the engine will shut down in approximately 30 seconds. Once the ignition key has been cycled, the engine will restart and run for 30 seconds. This will continue to happen until the low coolant indicator issue is resolved.


Reference Information
Schematic Reference

Engine Cooling Schematics ()
Connector End View Reference

Component Connector End Views
Description and Operation

Cooling System Description and Operation (Description and Operation)
Electrical Information Reference

* Circuit Testing
* Connector Repairs
* Testing for Intermittent Conditions and Poor Connections
* Wiring Repairs



Circuit/System Verification

The low coolant indicator should be OFF with the engine coolant at the proper level.


Circuit/System Testing

Important: Circuit/System Verification must be performed before performing the Circuit/System Testing.



1. Ignition OFF, disconnect the harness connector at the coolant level switch.
2. Install a 3A fused jumper wire between the signal circuit terminal and ground.
3. Engine running, verify the low coolant indicator turns OFF.

• If the indicator does not turn OFF, test the signal circuit for an open/high resistance.
• If the indicator turns OFF, test the ground circuit for an open/high resistance.

4. If all circuits test normal, replace the coolant level switch.



Repair Instructions

* Instrument Cluster Replacement
* Radiator Surge Tank Replacement (Service and Repair)
* Control Module References for ECM replacement, setup, and programming



Repair Verification

Verify that the low coolant indicator is OFF with the engine coolant at the proper level.