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 HVAC control module. The normal state of the engine coolant level switch is closed when in contact with coolant.


Reference Information
Schematic Reference

Engine Cooling Schematics (Electrical Diagrams)
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

* Radiator Surge Tank Replacement (Non-HP2) (Service and Repair)
* Control Module References
* Instrument Cluster Replacement (without RPO SLT)



Repair Verification

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