0336859 JOHNSON GATE, Reverse

Illustration 1 g00849532
Test Step 1. Check for Connector Damage
Turn the engine control to the OFF position.
Thoroughly inspect the ECM connector J1/P1. Inspect all of the other connectors. Refer to Troubleshooting, "Inspecting Electrical Connectors" for details.
Perform a 45 N (10 lb) pull test on each of the wires in the ECM connector that are associated with the circuit.
Check the ECM connector (allen head screw) for the proper torque of 6.0 N m (55 lb in).
Check the customer connector (allen head screw) for the proper torque of 2.25 0.25 N m (20 2 lb in).
Check the harness and the wiring for abrasion and pinch points.Expected Result:The connectors and wiring should be free of the following problems: damage, abrasion, corrosion and incorrect attachment.Results:
OK - The connectors and wiring are okay. Proceed to test step 2.
Not OK - Repair: Repair the connector and/or wiring or replace the connector and/or wiring. Stop.Test Step 2. Check the Fuel Position Multiplier.
Disconnect main power.
Disconnect the customer supplied fuel position multiplier.
Connect a throttle position sensor to the wiring in order to simulate the signal from the Fuel Position Multiplier. Ensure that the sensor will generate a 500 Hz PWM signal. The sensor should generate an identical signal as the attachment for the torque limit on the locomotive. Connect the sensor directly to the wiring that sends the PWM signal to the ECM.Note: Remember to remove the sensor when the test is complete. Remember to reconnect the Fuel Position Multiplier.
Connect the ET to the service tool connector.
Connect main power.
Observe the fuel position multiplier on the ET.
Adjust the throttle sensor to the minimum input position.
Slowly adjust the throttle sensor toward the maximum input position. Monitor the ET.Expected Result:The ET should display 1.000 for the fuel position multiplier when the throttle sensor is at the minimum input. The ET should display 0.000 for the fuel position multiplier when the throttle sensor is at the maximum input.Results:
OK - The wiring and connectors from the Fuel Position Multiplier to the ECM are okay.Repair: The problem appears to be the Customer Supplied Fuel Position Multiplier. Refer to the OEM Manual. Stop.
Not OK - The ECM is not receiving the proper signal from the throttle sensor. Proceed to test step 3.Test Step 3. Check the ECM Input.
Disconnect the main power.
Set the multimeter to VDC. Press "Hz" button twice so the "%" symbol is displayed.
Measure the duty cycle at the ECM connectors between P2-25 and P1-5.
Connect the main power.
Monitor the Duty Cycle output of the throttle sensor on the multimeter. Monitor the Fuel Position Multiplier on the ET. Adjust the throttle sensor from the minimum signal to the maximum signal.
Disconnect the main power.
Restore the wiring to the original configuration.Note: The fuel position multiplier on the ET will NOT match the Duty Cycle on the multimeter.Expected Result:The Duty Cycle should be between 5 and 10 percent at the minimum signal. The Duty Cycle should be between 90 and 95 percent at the maximum signal. The reading for the Fuel Position Multiplier should be 1.000 when the throttle sensor is sending the minimum signal. The reading for the Fuel Position Multiplier should be 0.000 when the throttle sensor is sending the maximum signal. The reading for the Fuel Position Multiplier should be between 1.000 and 0.000 as the Duty Cycle increases and/or decreases.Results:
OK - The duty cycle reading is correct on the multimeter. The reading for the Fuel Position Multiplier corresponds with adjustments to the throttle sensor.Repair: The problem may be intermittent. If the problem is intermittent refer to Troubleshooting, "Inspecting Electrical Connectors". Stop.
Throttle Position Reading NOT OK - The Duty Cycle reading is correct on the multimeter. The reading for the Fuel Position Multiplier is not correct on the ET.Repair: The problem appears to be in the ECM. Replace the ECM. Refer to Troubleshooting, "Replacing the ECM". Stop.
Duty Cycle Reading NOT OK - The Duty Cycle reading is not correct. There is a problem with the wiring between P2-25 and the throttle sensor (attachment from previous step). Proceed to test step 4.Test Step 4. Check the Signal at the Customer Connector.
Disconnect the main power.
Set the multimeter to VDC. Press the "Hz" button twice so the "%" symbol is displayed.
Measure the duty cycle at the customer connector between P3-24 and ECM connector P1-5.
Connect the main power.
Monitor the Duty Cycle output of the throttle sensor on the multimeter. Adjust the throttle sensor from the minimum signal to the maximum signal.
Disconnect the main power.
Restore the wiring to the original configuration.Expected Result:The Duty Cycle should be between 5 and 10 percent at the minimum signal. The Duty Cycle should be between 90 and 95 percent at the maximum signal.Results:
OK - The problem is in the wiring or connectors between the customer connector J3/P3 and the ECM connector J2/P2.Repair: Repair the connector and/or wiring or replace the connector and/or wiring. Stop.
Not OK - Repair: The problem appears to be the Customer Supplied Fuel Position Multiplier. Refer to the OEM Manual. Stop.