RING-BACKUP 0875397 - Caterpillar

System Operation Description:Use this procedure to troubleshoot any suspect problems with the engine coolant level sensor.The engine coolant level sensor provides a means of monitoring the engine coolant level in order to warn the operator in the event that the coolant level is low. The engine coolant level sensor is usually located in the top tank of the radiator. The sensor should be immersed in coolant at all times.When the sensor is immersed in coolant, an internal switch is closed. When the internal switch closes, the signal for the engine coolant level is grounded through the sensor return. The Electronic Control Module (ECM) detects the grounded signal on the input for the engine coolant level. If the signal is not present, an event code is generated.Verify that the coolant level has been programmed to "Installed" on the configuration screen on the Caterpillar Electronic Technician (ET). If the coolant level is not programmed, Cat ET will display "Not Installed" for the parameter.
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Schematic for coolant level sensor
The connection of any electrical equipment and the disconnection of any electrical equipment may cause an explosion hazard which may result in injury or death. Do not connect any electrical equipment or disconnect any electrical equipment in an explosive atmosphere.
Test Step 1. Check the Coolant Level
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.
Stop the engine. Allow the engine to cool.
Check the coolant level. Refer to the engine's Operation and Maintenance Manual for the proper procedure.Expected Result:The coolant level is low.Results:
OK - The coolant level is low.Repair: Add coolant according to the procedure in the Operation and Maintenance Manual. Identify the source of the coolant leak and fix the problem. Verify that the original problem is resolved.STOP
Not OK - The coolant is at the proper level. Proceed to Test Step 2.Test Step 2. Inspect the Electrical Connectors and the Wiring
Turn the keyswitch to the OFF position.
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Left side engine view (typical example) (1) J1/P1 ECM connector
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Left side engine view (typical example) (2) P61 Customer connector
Thoroughly inspect connectors (1) and (2). Inspect the J800/P800 connectors for the engine coolant level sensor. Refer to Troubleshooting, "Electrical Connectors - Inspect".
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P1 terminals that are associated with the engine coolant level sensor (P1-3) Digital return (P1-4) +8 V Digital supply (P1-46) Engine coolant level
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J61 and P61 terminals that are associated with the engine coolant level sensor (8) +8 V Digital supply (15) Digital return (36) Engine coolant level
Perform a 45 N (10 lb) pull test on each of the wires in the ECM connector, the customer connector, and the sensor connector that is associated with the circuit for the engine coolant level sensor.
Check the allen head screw on the ECM connector and the customer connector for the proper torque. Refer to Troubleshooting, "Electrical Connectors - Inspect" for the correct torque.Expected Result:All connectors, pins, and