0387410 JOHNSON FUEL TANK ASSY

Illustration 1 g01024049
Typical circuit with EMCP II
Illustration 2 g01024091
Typical circuit with EMS IITest Step 1. Check for Connector Damage.
Turn the ECS to the OFF/RESET position.
Thoroughly inspect the ECM connectors J1/P1 and J2/P2. Inspect all of the other connectors. Refer to the diagnostic functional test 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 for pinch points.Expected Result:All connectors, pins, and sockets are completely coupled and/or inserted, and the harness and wiring are free of corrosion, of abrasion or of pinch points.Results:
OK - The connectors and wiring are okay. Proceed to Test Step 2.
Not OK - The connectors and/or wiring are not okay.Repair: Repair the connectors or wiring and/or replace the connectors or wiring. Stop.Test Step 2. Check the Supply Voltage to the Speed Control.
Turn the circuit breaker at the battery to the ON position.
Turn the ECS to the STOP position.
Connect one probe of a voltmeter to the +Battery terminal of the speed control. Connect one probe of the voltmeter to the -Battery terminal of the speed control.Expected Result:The voltage is 24 3 VDC.Results:
OK - The voltage is 24 3 VDC. The voltage supply to the speed control is correct. Proceed to Test Step 3.
Not OK - The voltage is not 24 3 VDC.Repair: Check wire 998-BR for continuity to the ECM connector P1-29. Check wire 104-RD for continuity to the breaker for the "relay breaker". Check the "relay breaker" and the "battery breaker" in order to ensure that the breakers are not tripped. Stop.Test Step 3. Determine the Component that has Failed.
Determine if the problem is with the input for the throttle or the droop.
Turn the ECS to the STOP position.
Observe the position of the throttle on the Caterpillar Electronic Technician (ET) as you turn the speed adjust potentiometer.
Observe the droop on Cat ET as you turn the droop adjust potentiometer.
Select "UNSURE" if the source of the problem is unknown.Expected Result:The throttle position on Cat ET varies with the turning of the speed adjust potentiometer. The droop on Cat ET varies with the turning of the droop adjust potentiometer.Results:
RATED SPEED - The throttle position on Cat ET does not vary with the turning of the speed adjust potentiometer. Proceed to Test Step 4.
DROOP SPEED - The droop on Cat ET does not vary with the turning of the droop adjust potentiometer. Proceed to Test Step 5.
Unsure - The problem is not apparent. Proceed to Test Step 4.Test Step 4. Check the Throttle Position.
Turn the ECS to the STOP position.
Observe the position of the throttle on Cat ET.
Turn the speed adjust potentiometer to the lowest setting.
60 Hz equals 1369 rpm
50 Hz equals 1141 rpm
Start at the low idle position. Slowly turn the speed adjust potentiometer in the other direction. Monitor the position of the throttle on Cat ET.Expected Result:The throttle position on Cat ET reads 0 percent at the lowest setting and 0 to 100 percent as the speed adjust potentiometer is adjusted.Results:
OK - The speed control is operating correctly.Repair: The problem may be intermittent. If the problem is intermittent, perform the diagnostic functional test Troubleshooting, "Inspecting Electrical Connectors". Stop.
Not OK - The throttle position on Cat ET does not vary as the speed adjust potentiometer is adjusted. Proceed to Test Step 6.Test Step 5. Check the Droop Signal on Cat ET.
Turn the ECS to the STOP position.
Observe the droop on Cat ET.
Turn the droop adjust potentiometer in a counterclockwise direction.
Slowly turn the droop adjust potentiometer in a clockwise direction. Monitor the droop on Cat ET. Note: Do not overturn the droop adjust potentiometer in the clockwise direction. The signal will become erratic.Expected Result:The droop on Cat ET reads 0 percent at the lowest setting and 0 to 10 percent as the droop adjust potentiometer is adjusted.Results:
OK - The droop is operating correctly.Repair: The problem may be intermittent. If the problem is intermittent, perform the diagnostic functional test Troubleshooting, "Inspecting Electrical Connectors". Stop.
Not OK - The droop on Cat ET does not vary as the droop adjust potentiometer is adjusted. Proceed to Test Step 7.Test Step 6. Check the Speed Control.
Remove the wire from the S terminal at the speed control.
Set the multimeter to "VDC". Press the "Hz" button twice so that the % symbol is displayed.
Place one probe of the multimeter on the S terminal of the speed control. Place the other probe on the -Battery terminal of the speed control.
Monitor the output of the percent duty cycle from the speed control on the multimeter. Turn the speed adjust potentiometer from the low setting to the high setting.Note: The throttle position on Cat