GUARD AS 7T6246 - Caterpillar

Illustration 1 g01139153
Schematic of the Hydraulic Oil Temperature SenderThis diagnostic code is recorded when the signal voltage of the hydraulic oil temperature sender and the voltage is too low. The Hydraulic Pump ECM records this diagnostic code from information received from the monitoring system through the Cat Data Link.The possible causes of this diagnostic code are listed below:
The sender has failed.
The signal circuit in the machine harness is shorted to ground.
The ECM has failed. This is unlikely. The diagnostic code of CID 0600 FMI 04 will be logged in the internal memory of the ECM.Note: Before performing this procedure, inspect the harness connectors that are involved in the circuit. Poor connections can often be the cause of a problem in an electrical circuit. Verify that all connections in the circuit are clean, that all connections are secure and that all connections are in good condition. If a problem with a connection is found, correct the problem and verify that this diagnostic code is active before performing this procedure. Note: The following test procedure may create other diagnostic codes. Ignore these created diagnostic codes and clear the diagnostic codes when the problem has been corrected.Test Step 1. CHECK THE SENDER.
Turn the disconnect switch and the key start switch to the ON position.
Disconnect the machine harness from the sender.Expected Result:The diagnostic code CID 0600 FMI 04 is no longer present.Results:
OK - The diagnostic code CID 0600 FMI 04 is no longer present. This indicates that the failure is no longer present. The sender has failed. Repair: Replace the sender.STOP
NOT OK - The diagnostic code remains. The failure remains present. The sender is not causing the failure. Proceed to test step 2.Test Step 2. CHECK THE HARNESS.
The sender remains disconnected from the machine harness.
Turn the disconnect switch and the key start switch to the OFF position.
Disconnect the CN-2 machine harness connector from the Monitoring System.
At the machine harness connector for the sender, measure the resistance between the signal contact (wire 491-PK) and frame ground.Expected Result:The resistance is greater than 5000 ohms.Results:
OK - The resistance is greater than 5000 ohms. The harness circuit resistance is correct. The Hydraulic Pump ECM may have failed.Repair: It is unlikely that the Hydraulic Pump ECM has failed. Exit this procedure, and perform this procedure again. If the failure is not found, replace the Hydraulic Pump ECM. See Testing and Adjusting, "Electronic Control Module (ECM) - Replace".STOP
NOT OK - The resistance is less than 5000 ohms. The machine harness has failed. There is a short between frame ground and the signal circuit in the machine harness. Repair: Repair the machine harness or replace the machine harness.STOPTest Step 3. CHECK THE STATUS OF THE DIAGNOSTIC CODE
Inspect the harness connectors and clean the contacts of the harness connectors. Check the wires for damage to the insulation that is caused by excessive heat, battery acid, or chafing.
Perform a 45 N (10 lb) pull test on each of the wires that are associated with the sensor circuit.
Reconnect all harness connectors. Make sure