SPRING-VALVE 7W2109 - Caterpillar

Illustration 1 g00527487
System Schematic For Engine Coolant Loss Sensor(ECLS)The EMCP II+ monitors engine coolant for loss of coolant in order to protect the engine in case of a coolant temperature problem. The engine coolant loss function is optional. The engine coolant loss 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 (approximately +5 DCV) is sent to the GSC+. When coolant is present at the sensor, a low signal (battery negative) is sent to the GSC+.Note: The GSC+ is usually programmed to treat a coolant loss sensor fault as an alarm fault. P004 is equal to 0. If the GSC+ is programmed to shutdown, P004 is equal to 1. The operator is not required to press the "Alarm Codes" key in order to view the CID 111 FMI 3. The CID 111 FMI 3 is automatically shown on the upper display.Note: Faults are created when the harness connector is disconnected from the GSC+ during these troubleshooting procedures. Clear the created faults after the particular fault is corrected and after the particular fault is cleared. In a system that is operating properly, when the harness connector is removed from the GSC+, the following diagnostic fault 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 175 FMI 3 - Temperature Sensor (Engine Oil)CID 190 FMI 3 - Speed Sensor (Engine)CID 336 FMI 2 - Switch (Engine Control)CID 590 FMI 9 - Engine (ECM)The possible causes of a CID 111 FMI 3 fault are listed below.
A short circuit to battery positive of the sensor signal.
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 flashing indicator means that the fault is active. The GSC+ treats a CID 111 FMI 3 fault as an alarm fault. Active alarm faults are shown on the display when the alarm codes key is pressed and the engine control switch (ECS) is in any position except the OFF/RESET position. For an inactive fault, the problem may be intermittent. See Testing And Adjusting, "Electrical Connector - Inspect" in order to troubleshoot an inactive fault. Also use the preceding system schematic. Clear the fault from the fault log after troubleshooting is complete.Note: If a sensor supply fault (CID 269) is active, correct the sensor supply fault prior to proceeding with this procedure.
Check the Sensor Voltage Supply Circuit.
Turn the ECS to OFF/RESET. Then, turn the ECS to the STOP position.
Disconnect the sensor from the engine harness. The sensor remains fastened to the engine.
At the engine harness side of the sensor connector, measure the voltage (DCV) that is between contact "A" and contact "B". Contact