DISPOSAL GP 4645553 - Caterpillar

Illustration 1 g01094676
ReferenceRefer to the Electrical Schematic that is applicable for your machine.This diagnostic code is associated with the cables that connect the AccuGrade - Grade Control System.When this diagnostic code is active, there is a problem with the cable harness or a problem with the CAN data link.Test Step 1. CYCLE THE POWER TO THE SYSTEM
Turn the key start switch for the machine to the "OFF" position.
Turn the key start switch for the machine to the "ON" position.Expected Result:The diagnostic code is not active.Results:
YES - The diagnostic code is not active. Repair: Return the machine to normal operation.STOP
NO - The diagnostic code is still active. Proceed to Test Step 3.Test Step 2. CHECK THE RESISTANCE OF THE CAN CIRCUIT
Place the key start switch and the disconnect switch in the "OFF" position.
Take the following measurement at the connector for the Right or the Left side Laser/sonic harness. Measure the resistance between contact C (wire L854-YL) and contact D (wire L855-GN).Expected Result:The resistance measurement is 60 6 ohms.Results:
YES - The resistance measurement is 60 6 ohms. Proceed to Test Step 3.
NO - The resistance measurement is NOT 60 6 ohms. Proceed to Test Step 3.Test Step 3. CHECK THE TERMINATION RESISTOR.
Place the key start switch and the disconnect switch in the "OFF" position.
Disconnect the 3-pin connector from the four termination resistors.
Measure the resistance between contact A (wire L854-YL) and contact B (wire L855-GN) for one set of resistors. Measure the resistance between contact A (wire L856-YL) and contact B (wire L857-GN) for the other set of resistors. Note the resistance.Expected Result:The resistance measurements are 120 12 ohms.Results:
YES - The resistance measurements are 120 12 ohms. Reconnect the resistors. Contact your Technical communicator for a possible consultation with Caterpillar.STOP
NO - One or both resistance measurements are NOT 120 12 ohms. Repair: Replace the termination resistor(s) that did not measure 120 12 ohms.STOP