HARNESS AS-ENGINE 3331238 - Caterpillar

Illustration 1 g00529671
System Schematic For Engine Oil Temperature Sensor (EOTS)The EMCP II+ system monitors the engine coolant temperature in order to protect the engine from a coolant temperature problem. The coolant temperature sensor is mounted in the water jacket. The exact location of the engine coolant temperature sensor varies depending on the engine model.The sensor is powered by an 8 volt sensor supply from the GSC+. The coolant temperature signal is a pulse width modulated signal. The base frequency of the signal is 455 Hz (370 to 550 Hz). As temperature changes, the duty cycle of the signal varies from 10 to 95 percent.
-40°C (-40°F) is approximately 10% of the duty cycle, which is approximately 1.0 DCV.
135°C (275°F) is approximately 93% of the duty cycle.Note: The GSC+ is usually programmed to treat an oil temperature sensor problem as an alarm fault. The factory default for P004 is 0. The GSC+ may be programmed to shutdown for an oil temperature sensor fault. P004 is 1 for a shutdown. The operator is not required to press the "Alarm Codes" key in order to view the CID 175 FMI 2. The CID 175 FMI 2 is automatically shown on the upper display.The possible causes of a CID 175 FMI 2 are listed below:
The base frequency of the sensor signal is beyond accepted limits.
The duty cycle of the sensor signal is beyond accepted limits.Begin performing these procedures only when CID 175 FMI 2 is showing and the "DIAG" indicator is FLASHING on the upper display. The GSC+ treats a CID 175 FMI 2 as an alarm fault. Active alarm faults are shown on the display when the "Alarm Codes" key is pressed. The engine control switch (ECS) must be in any position except the OFF/RESET position. For an inactive fault, the problem may be intermittent. In order to troubleshoot an inactive fault, use the preceding system schematic. See Testing And Adjusting, "Electrical Connector - Inspect". Clear the diagnostic code from the fault log after troubleshooting is complete.Note: This procedure can be replaced by troubleshooting the sensor signal with a meter that is capable of measuring frequency and duty cycle. See Testing And Adjusting, "Pulse Width Modulated (PWM) Sensor - Test".Note: If a Sensor Supply fault (CID 269) is active, correct the fault prior to proceeding with this procedure.Test Step 1. CHECK THE GSC+ AND THE HARNESS.
Make sure that CID 175 FMI 2 is showing on the display.
Turn the ECS to the OFF/RESET position.
Disconnect the sensor from the engine harness. The sensor remains fastened to the engine.
Turn the ECS to the STOP position.
Press the "Alarm Codes" key. The "Alarm Codes" key does not need to be pressed for shutdown faults. Check if the CID 175 FMI 2 is not showing. This means that the CID 175 FMI 2 is inactive. Check if the CID 175 FMI 3 is now showing. CID 175 FMI 3 is now active.Expected Result:CID 175 FMI 2 is not