SEAL-SHAFT 4858328 - Caterpillar

Illustration 1 g00483875
System Schematic For Engine Coolant Loss Sensor (ECLS)The EMCP II monitors the engine coolant for loss of coolant in order to protect the engine in case of a problem with the coolant temperature. This function is an option and the function requires the presence of the optional coolant loss sensor. The coolant loss sensor is usually mounted near the top of the radiator.The sensor is powered by an 8 volt sensor supply from the GSC. When coolant is NOT present at the sensor, a high signal (+5 DCV) is sent to the GSC. When coolant is present at the sensor, a low signal (B-) is sent to the GSC.Note: The GSC is usually programmed to treat a fault with the coolant loss sensor as an alarm fault (P04 = 0). The GSC is usually programmed to treat a fault with the coolant loss sensor as an shutdown fault (P04 = 1). The diagnostic codes are automatically shown on the upper display.Note: Faults are created when the harness connector (40 contact) is disconnected from the GSC during these troubleshooting procedures. Clear these created faults after the particular fault is corrected. In a properly operating system, when the harness connector is removed from the GSC, the following diagnostic codes are recorded.
CID 100 FMI 2 pressure sensor (engine oil)
CID 110 FMI 2 temperature sensor (engine coolant)
CID 111 FMI 3 fluid level sensor (engine coolant)
CID 190 FMI 3 speed sensor (engine)
CID 336 FMI 2 switch (engine control)
CID 590 FMI 9 engine ECMProcedureThis diagnostic code can be caused by a short to the + battery of the sensor signal. Another possible cause is an open circuit of the sensor signal.Begin performing these procedures only when CID 111 FMI 3 is showing and the "DIAG" indicator is FLASHING on the upper display. The GSC treats a CID 111 FMI 3 as an alarm fault. Active alarm faults are shown on the display when the alarm codes key is pressed and the ECS is in any position except the OFF/RESET position. For an inactive fault, the problem may be intermittent. To troubleshoot an inactive fault, use the preceding system schematic and see Testing And Adjusting, "Electrical Connector - Inspect". Clear the diagnostic code from the fault log after troubleshooting is complete.Note: If CID 269 is active, then correct the diagnostic code prior to proceeding with this procedure.
Check the circuit for the supply.
Turn the ECS to OFF/RESET and then turn the ECS to the STOP position.
Disconnect the sensor from the engine harness. The sensor remains fastened to the engine.
At the side of the engine harness on the sensor connector, measure the voltage (DCV) between contact "A" (supply) and contact "B" (sensor ground). Expected Result: The voltage should be 8.0 0.5 DCV. Results:
OK - The supply circuit functions properly. Proceed to 2.
NOT OK - The supply circuit is faulty. Check the upper display for a CID 269. If necessary, correct the fault. If a CID 269 is not showing on the upper display, then the