TANK GP-HYDRAULIC 3454581 - Caterpillar

Illustration 1 g01447774
Schematic of the sensor for the Autolube Grease LevelThis diagnostic code is associated with the sensor for the Autolube Grease Level. The FMI 03 indicates that the ECM for the power train has detected that the voltage of the sensor circuit is above the threshold. In addition to monitoring the voltage of the sensor signal, the ECM monitors the resistance of the sensor signal. The ECM associates the resistance value of the sensor circuit with a specific amount of lube in the lube tank.When the lube tank is nearly empty, the resistance in the sensor circuit is approximately 243 2.43 ohms. When the lube tank is full, the resistance of the sensor is approximately 33 .33 ohms.Some of the conditions that can cause the diagnostic code are listed below.
The sensor has failed.
The ground circuit for the sensor is open in the machine harness.
The signal circuit in the machine harness is open or the sensor is disconnected.
The ECM has failed. This is unlikely.Test Step 1. CHECK THE RESISTANCE OF THE SENSOR
Turn the disconnect switch and the key start switch to the OFF position.
Disconnect the machine harness connector from the sensor for the Autolube Grease Level.
At the connector for the sensor, measure the resistance between the contact 1 and the contact 2. Expected Result:The resistance measurement should approximately be a range of 243 ohms to 33 ohms.Results:
OK - The resistance measurement is in the correct range. The sensor is OK. Proceed to Test Step 3.
NOT OK - The resistance measurement is not in the correct range. The fuel level sender has failed.Repair: Replace the fuel level sender. Ensure that the new sensor corrects the problem.STOPTest Step 2. CHECK THE GROUND CIRCUIT OF THE HARNESS The sensor remains disconnected from the machine harness. The disconnect switch and the key start switch remain in the OFF position.
Disconnect the J1 machine harness connector from the ECM.
Measure the resistance from contact 2 (wire 202-BK) at the harness connector for the sensor to frame ground.Expected Result:The resistance measurement is less than 5 ohms.Results:
OK - The resistance measurement is less than 5.0 ohms. The ground circuit is correct. Proceed to Test Step 3.
NOT OK - The resistance measurement is greater than 5.0 ohms. There is an open circuit or a bad connection in the ground circuit for the sensor.Repair: A resistance measurement that is greater than 5000 ohms could indicate that a wire is either not connected or is open. A resistance measurement that is greater than 5 ohms but less than 5000 ohms could indicate that one of the connection points or a splice connection in the circuit is not open but is not a good connection.Refer to the complete machine Electrical System Schematic. Ensure that all connections and splices in the ground circuit for the sensor are clean, secure and in good condition.Start at the component connector for the suspect circuit. While checking the wire for an open or a bad connection point, work your way through the circuit in order