COVER ASSEM. 2S7852 - Caterpillar

Table 1
ECM Pin Number Expected Voltage Range
J2-56 0.5V to 4.5V
J2-57 0V
J2-64 0.5V to 4.5V
J2-65 0.5V to 4.5V
J2-66 0V
J2-67 0.5V to 4.5V
J2-68 0.5V to 4.5V
J2-69 0V
J2-70 0.5V to 4.5V Expected Result:The shield wire does not have a voltage. A voltage on the shield wire means that there is a short to the battery. The voltage of the wires for the Cat® Data Link is correct.Results:
OK - The voltages of the wires for the Data Links are correct. Proceed to Test Step 7
NOT OK - The voltage is greater than 4.5 V.Repair: Repair the machine harness or replace the harness.Proceed to Test Step9
NOT OK - The voltage is less than 0.5 V. Proceed to Test Step 5.Test Step 5. CHECK FOR A SHORT TO GROUND
Turn the keyswitch and the disconnect switch to the OFF position.
Disconnect the J2 harness connector for the Implement ECM.Disconnect the harness connector for the Fluid Level Monitoring Keypad.
Measure the resistance of wire K960-YL(Yellow)to an unpainted frame ground. Measure the resistance of wire K961-GN(Green)to an unpainted frame ground.Expected Result:The resistance measurement is greater than 5000 ohms.Results:
OK - The resistance measurement is correct. Proceed to Test Step 6
NOT OK - The resistance measurement is not correct. The wire with the low resistance measurement is shorted to ground.Repair: Repair the machine harness or replace the machine harness.Proceed to Test Step 9Test Step 6. CHECK FOR A SHORT IN THE WIRES FOR THE DATA LINK.
The keyswitch and the disconnect switch remain in the OFF position.
Measure the continuity between the data link wires.Expected Result:The resistance measurement is greater than 5000 ohms.Results:
OK - The resistance measurement is correct. Proceed to Test Step 7
NOT OK - The resistance measurement is not correct. The wires for the data link are connected.Repair: Repair the machine harness or replace the machine harness.Proceed to Test Step 9Test Step 7. CHECK THE TERMINATING RESISTORS
The keyswitch and the disconnect switch remain in the OFF position.
The terminating resistors remain disconnected.
Check the terminating resistor connectors for the following:
Moisture
Corrosion
Damaged terminals
Loose connections
Measure the resistance between terminal A and B of each terminating resistor that was removed from the CAN circuit.Expected Result:The resistance measurement is approximately 120 ohms.Results:
OK - Both resistance measurements are approximately 120 ohms. The terminating resistors have not failed. Reinstall the terminating resistors. Proceed to Test Step 8.
NOT OK - The resistance measurement is not approximately 120 ohms. One of the resistors is not functioning properly.Repair: Replace the terminating resistor that has failed.Proceed to Test Step 9Test Step 8. CHECK THE HARNESS.Note: Two 120 Ohm resistors should be located on the CAN Data Link. A resistance of 60 ohms should be found at any point on the data link.
The keyswitch and the disconnect switch remain in the OFF position.
Use an electrical spoon to connect to the back of the harness connector for each ECM that has communication issues.
Measure the resistance across the CAN line at each connector in order to find the open wire. If the resistance measurement is 60 ohms, that connector does not have an open between either terminating