PUMP AS-FUEL PRIMING 6N6800 - Caterpillar

In order to find the cause of an emergency stop shutdown, perform this procedure.Note: This procedure requires the Remote Start Switch to be opened and/or closed many times. In order to ease the troubleshooting process, a switch that is locally acquired can be connected to the terminals of the Remote Start Signal in the customer connection box. The terminals for the Remote Start Signal are terminal 57 and terminal 30.
Check For The Obvious Causes.
The Emergency Stop Push Button (ESPB) that is located on the control panel has been pressed.
The optional ESPB that is located on the enclosure has been pressed.Expected Result: Either the control panel or the optional ESPB that is located on the enclosure has been pressed. The indicator for an emergency stop fault is ON.Results:
OK: The system is operating properly. Someone has pushed the ESPB. Investigate the need for the emergency stop. Open the Remote Start Switch in order to reset all emergency stop buttons and clear all faults. Once the need for the emergency stop has been identified and the problem is solved, close the Remote Start Switch. STOP.
Not OK: The emergency stop push buttons have NOT been pressed, but the indicator for the emergency stop fault is ON. Proceed to the next Step.
Check the Circuitry For The ESPB (Check 1).
Open the Remote Starting Switch.Expected Result: The indicator for the emergency stop fault should turn OFF.Results:
OK: The indicator for the emergency stop fault is not ON. The system is working properly. The problem is not present now. The problem may be intermittent. Check the harness and all electrical connections of the circuit for the ESPB. See Testing And Adjusting, "Electrical Connector Inspection". STOP.
Not OK: After the Remote Start Switch has been opened, the indicator for the emergency stop fault does NOT turn OFF. Also, the indicator for the emergency stop turns ON again. Proceed to the next Step.
Check The Circuitry For The ESPB (Check 2).
Prepare to measure the resistance from contact 20 of the control board to "B-" (battery negative terminal).
Measure the resistance.Expected Result: The resistance should measure 5 ohms or less.Results:
OK: The resistance is 5 ohms or less. The wire harness is shorted to "B-" between the emergency stop signal and the ESPB. The emergency stop signal is found at contact 20 of the control board. See Schematics And Wiring Diagrams. Remove one component or wire at a time that is in series with the emergency stop signal until the faulty component or the faulty wire is isolated. The emergency stop signal is found at contact 20 of the control board. Repair the faulty component or the faulty wiring or replace the faulty component or the faulty wiring. STOP.
Not OK: The resistance is greater than 5 ohms. Therefore, the control board is faulty. Replace the control board. STOP.