LEVER 9R7678 - Caterpillar

Use this procedure in order to troubleshoot low coolant level or use this procedure if one of the following codes is active. Refer to Troubleshooting, "Event Codes" for information about event codes. Refer to Troubleshooting, "Diagnostic Trouble Codes" for information about diagnostic codes. Access the monitoring system on Caterpillar Electronic Technician (ET) in order to view the current trip points for these codes. For information on the engine monitoring system, refer to Troubleshooting, "Engine Monitoring System".Note: Some of the following codes may not be applicable for certain applications.
Table 1
Diagnostic Trouble Codes
Code Code Description
(code descriptions may vary) System Response
E057(2) Low Engine Coolant Level Derate Engine power is derated. The code is logged.
E059(1) Low Engine Coolant Level Warning The code is logged.
E552(2) Low Aftercooler Coolant Level Derate Engine power is derated. The code is logged.
E552(1) Low Aftercooler Coolant Level Warning The code is logged. Probable Causes
Low Coolant Level and/or Coolant Leakage
Coolant level sensorRecommended Actions
Note: The procedures have been listed in order of probability. Complete the procedures in order.
Table 2
Troubleshooting Test Steps Values Results
1. Low Coolant Level and/or Coolant Leakage
A. Inspect the coolant level.
Coolant level
Result: The engine coolant level is OK.
Proceed to Test Step 2.
Result: The engine coolant level is not OK.
Troubleshoot the cause of the incorrect coolant level.
1. Check for the correct mixture of antifreeze and water. Refer to Operation and Maintenance Manual.
2. Check the cooling system for leaks. Refer to Systems Operation/Testing and Adjusting, "Cooling System - Test" for the correct procedure. Repair any leaks immediately.
3. Check for air in the cooling system. Refer to Systems Operation/Testing and Adjusting, "Testing the Cooling System" for the correct procedure.
2. Faulty Sensor
A. If an electrical problem with the coolant level sensor is suspected, refer to Troubleshooting, "Coolant Level - Test" for information that is related to troubleshooting an electrical problem with the coolant level sensor.
Coolant level sensor
Result: The coolant level sensor is not operating properly.
Replace the coolant level sensor.
Complete the procedure in the order in which the steps are listed. If the procedure did not correct the issue, contact your Cat dealer Technical Communicator (TC). For further assistance, your TC can confer with the Dealer Solutions Network (DSN).