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 | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance |
|---|---|---|---|---|
Coolant Level Switch Signal | Indicator OFF | Indicator ON | -- | -- |
Ground | -- | Indicator ON | -- | -- |
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
Connector End View Reference
Description and Operation
Cooling System Description and Operation
Electrical Information Reference
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.
- Ignition OFF, disconnect the harness connector at the coolant level switch.
- Install a 3A fused jumper wire between the signal circuit terminal and ground.
- Engine running, verify the low coolant indicator turns OFF.
- If all circuits test normal, replace the coolant level switch.
| ⇒ | 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. |
Repair Instructions
| • | 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.
