SEAL-RING 9P1331 - Caterpillar

System Operation Description:Use this procedure to troubleshoot any suspect problems with the circuit for the coolant level sensor.The coolant level sensor monitors the engine coolant level in order to warn the operator when the coolant level is low.
Illustration 1 g01150024
Components of the coolant level sensor
(1) Sensor
(2) Sensor probe (brass dowel)
(3) Outer coating When the probe is not immersed in coolant, approximately +5 VDC is sourced to the sensor signal wire. When this condition is detected by the Electronic Control Module (ECM), an event code is activated.Prior to troubleshooting any problems with the coolant level sensor, use Caterpillar Electronic Technician (ET) to check the installation status for the sensor. The coolant level sensors configuration parameter must be set to "Installed" in order for the ECM to monitor the signal from the sensor.The activation of an event code and/or a warning lamp is probably caused by a low coolant level. The next likely cause is a problem with the wiring harness, a connector, or the sensor.
Illustration 2 g02155949Test 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.
Remove electrical power from the ECM. Note: Allow the engine to cool prior to removal of the cooling system pressure cap.
Check the coolant level. Refer to the Operation and Maintenance Manual for the proper procedure to check the coolant level. Results:
OK - The coolant is at the proper level. Proceed to Test Step 2.
Not OK - The coolant level is low.Repair: Add coolant according to the procedure in the Operation and Maintenance Manual.There may be a leak in the cooling system. Identify the source of the coolant leak. Repair the leak. Refer to Systems Operation/Testing and Adjusting, "Cooling System" for additional information.STOPTest Step 2. Verify that the "Coolant Level Sensor" Parameter is Programmed Correctly
Connect Cat ET to the service tool connector.
Establish communication with the ECM.
Verify that the "Coolant Level Sensor" parameter is programmed to "Installed".
Remove electrical power from the ECM. Results:
The "Coolant Level Sensor" parameter is programmed correctly. - Proceed to Test Step 3.
The "Coolant Level Sensor" parameter is not programmed correctly. - Repair: Program the "Coolant Level Sensor" parameter to "Installed".Verify that the repair eliminates the problem.STOPTest Step 3. Check the Supply Voltage at the Sensor Connector