The Electronic Control Module (ECM) detects the following condition:
- Coolant level is low.
- The engine has been running for more than 30 seconds. This 30 second delay begins once the engine speed is greater than zero rpm.
- The parameter for "Coolant Level Sensor" is programmed to "Installed".
- The monitoring system parameter for "Low Coolant Level Derate" is enabled.
System Response:
The ECM will log the derate. The warning lamp will flash and the derate will be transmitted to the display. The ECM will derate the engine power at a rate of 1.67 percent per second while the event remains active. The ECM can derate the engine power as much as 100 percent of the available derate. The ECM will restore full engine power when there is a proper coolant level for 30 seconds.
- Low power
- The coolant level is most likely low.
- There may be a problem with the coolant level sensor.
Test Step 1. Check the Coolant Level
- Stop the engine.
Pressurized System: Hot coolant can cause serious burns. To open the cooling system filler cap, stop the engine and wait until the cooling system components are cool. Loosen the cooling system pressure cap slowly in order to relieve the pressure. |
- After allowing the engine to cool, check the coolant level. Refer to the Operation and Maintenance Manual for the proper procedure.
Note: The coolant level sensor should be completely immersed in coolant.
Expected Result:
The coolant level is low.
Results:
- OK - The coolant level was low.
Repair: Check the cooling system for leaks. Repair any problems that are found. Refill the cooling system to the proper level.
Stop.
- Not OK - The coolant level is not low.
Repair: There may be a problem with the coolant level sensor. Refer to the diagnostic functional test Troubleshooting, "Coolant Level Sensor Circuit - Test" in order to verify that the coolant level sensor is operating correctly.There may be an intermittent problem. Monitor the operation of the engine and repair any problems.Ensure that any repairs eliminate the problem.
Stop.