GASKET 6L8678 - Caterpillar

Which Generate This Code:This diagnostic code is associated with the laser receiver. The laser receiver is sending data that is one of the following:
Intermittent
Incorrect
InvalidSystem Response:When this diagnostic code is active, "Err 40" will be shown on the LCD of the display.Test Step 1. CHECK THE PLACEMENT OF THE LASER TRANSMITTER
Verify that the laser transmitter is at least 10 to 15 feet away from the machine.Expected Result:The laser transmitter is placed in the proper position.Results:
YES - The laser transmitter is placed at least 10 to 15 feet away from the machine. Proceed to Test Step 2.
NO - The laser transmitter is NOT placed at least 10 to 15 feet away from the machine.Repair: Position the laser transmitter 10 to 15 feet away from the machine.STOPTest Step 2. CHECK FOR AN OPEN IN THE CAN DATA LINK
Place the key start switch and the disconnect switch in the OFF position.
Disconnect the machine harness connectors "J1" and "J2" from the ECM.
At the harness connectors for the ECM, measure the resistance from contact "J2-64" (wire L856-YL) to contact "C" of the quick disconnect. Measure the resistance from "J2-65" (wire L857-GN) to contact "D" of the quick disconnect.Expected Result:The resistance measurement is less than 5 ohms.Results:
YES - The resistance measurement is less than 5 ohms. The circuit for the CAN data link is NOT open. Proceed to Test Step 3.
NO - The resistance measurement is greater than 5 ohms. There is an open or a bad connection in the circuit for the CAN data link.Repair: A resistance measurement that is greater than 5000 ohms could indicate that a wire is not connected or that a wire is open. A resistance measurement that is greater than 5 ohms but less than 5000 ohms could indicate that one of the connection points in the circuit is not an open but the connection is not a good connection.Refer to the complete Electrical System Schematic of the machine. Check all of the connectors that are in the circuit for the CAN data link. Ensure that all of the connections are clean, that all of the connections are secure and that all of the connections are in good condition. Repair the machine harness or replace the machine harness.STOPTest Step 3. CHECK THE CAN DATA LINK FOR A SHORT TO GROUND
The key start switch and the disconnect switch remain in the OFF position.
Measure the resistance between contact J2-64 (wire L856-YL) and frame ground. Measure the resistance between contact J2-65 (wire L857-GN) and frame ground. Note the resistance.Expected Result:The resistance measurements are greater than 5000 ohms.Results:
YES - Each resistance measurement is greater than 5000 ohms. The CAN data link is not shorted to another circuit in the machine harness.Repair: Contact your technical communicator for a possible consultation with Caterpillar.STOP
NO - One or more of the resistance measurements is less than 5000 ohms. There is a short in the machine harness.Repair: A wire in the circuit for the CAN data link is shorted.Refer to the complete Electrical System Schematic of the machine.