SPRING-GAS 2949284 - Caterpillar

Illustration 1 g01523595
This diagnostic code is associated with the harnesses that connect to the AccuGrade - Grade Control System or the internal AccuGrade CAN data link wiring of an AccuGrade component.System Response:When this diagnostic code is active, there is a problem with the harnesses for the AccuGrade - Grade Control System. The CAN data link that is used by the system is experiencing communication problems. System components may be experiencing intermittent communications. This results in lost system data.Test Step 1. CYCLE THE POWER TO THE SYSTEM
Move the "Power/Setup" switch on the display to the "OFF" position.
Turn the key start switch for the machine to the "OFF" position.
Turn the key start switch for the machine to the "ON" position.
Move the "Power/Setup" switch on the display to the "ON" position.
Check the status of the diagnostic code "CB 19".Expected Result:The diagnostic code is not active.Results:
YES - The diagnostic code is not active.Repair: The diagnostic code was caused by the display's internal CAN data link. Cycling the power to the system has reset the display. Return the machine to normal operation.STOP
NO - The diagnostic code is still active. Proceed to Test Step 2.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 sensor that is communicating on the AccuGrade CAN data link. Measure the resistance between contact C (wire 252-YL) and contact D (wire 262-GN).Expected Result:The resistance measurement is 60 6 ohms.Results:
YES - The resistance measurement is 60 6 ohms. Proceed to Test Step 4.
NO - The resistance measurement is NOT 60 6 ohms. Proceed to Test Step 3.Test Step 3. CHECK THE TERMINATION RESISTOR.
Disconnect the 3-pin connector for both of the termination resistors.
Measure the resistance across contact A (wire 252-YL) and contact B (wire 262-GN) for one resistor. Measure the resistance across contact A (wire 252-YL) and contact B (wire 262-GN) for the other resistor. Note the resistance.Expected Result:The resistance measurements are 120 12 ohms.Results:
YES - The resistance measurements are 120 12 ohms. Reconnect the resistors. Proceed to Test Step 4.
NO - One or both resistance measurements is NOT 120 12 ohms. Repair: Replace the termination resistor(s) that did not measure 120 12 ohms.STOPTest Step 4. 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 A (wire 252-YL) and frame ground. Measure the resistance between contact B (wire 262-GN) and frame ground. Note the resistances.Expected Result:The resistance measurements are greater than 5000 ohms.Results:
YES - The resistance measurements are greater than 5000 ohms. Proceed to Test Step 5.
NO - One or both resistance measurements are less than 5 ohms.Repair: The CAN data link is shorted to ground. Repair the harness or replace the harness.STOPTest Step 5. CHECK THE CAN DATA LINK FOR A SHORT TO "+" BATTERY
Turn the disconnect switch and the key start switch to the "ON" position.
Measure