0393423 JOHNSON GEARCASE ASSY.

Illustration 1 g01325176
Schematic of the power sensor's input with EMCP II+
For the actual wiring, refer to the generator's schematic diagram.
Illustration 2 g01325177
Schematic of the wiring for the load signal.
For the actual wiring, refer to the generator's schematic diagram. The potentiometer is optional. For further information, refer to Troubleshooting, "Ganerator Output Power Sensor - Set".
Test Step 1. Inspect the Electrical Connectors and Wiring
Remove the electrical power from the engine. Note: For the following steps, refer to Troubleshooting, "Electrical Connectors - Inspect".
Thoroughly inspect the following components:
J1/P1 connectors
J6/P6 connectors
The wiring and the connections between the ECM and the GSC+ (if equipped)
The wiring and the connections between the electronic control module and the power sensor (if equipped)
Check the torque of the allen head screw for the ECM connectors.
Perform a 45 N (10 lb) pull test on each of the wires that are associated with the circuit for the power sensor.
Check the harness and wiring for abrasion and for pinch points between the power sensor and the electronic control module. Expected Result:All connectors, pins, and sockets are connected properly. The connectors and the wiring do not have corrosion, abrasion, or pinch points.Results:
OK - The components are in good condition with proper connections. Proceed to Test Step 2.
Not OK - The components are not in good condition and/or at least one connection is improper.Repair: Perform the necessary repairs and/or replace parts, if necessary.STOPTest Step 2. Check for a Diagnostic Code
Connect Caterpillar Electronic Technician (ET) to the service tool connector. Refer to Troubleshooting, "Electronic Service Tools".
Start the engine and run the engine. Attempt to apply at least a 30 percent load to the generator.
Observe the "Active Diagnostic" screen on Cat ET. Allow a minimum of 30 seconds for any codes to activate. Look for these codes:
1719-3
1719-9
1719-12
Stop the engine. Expected Result:There are no active codes for the generator output power sensor.Results:
No active codes - There are no active codes for the generator output power sensor. There may be a logged code for the generator output power sensor.Repair: If there is a logged code for the generator output power sensor, there may be a problem with the wiring and/or a connector. Refer to Troubleshooting, "Electrical Connectors - Inspect".STOP
Active 1719-3 code - There is an active 1719-3 code, proceed to Test Step 3.
Active 1719-9 code - There is an active 1719-9 code, proceed to Test Step 6.
Active 1719-12 code - There is an active 1719-12 code. Proceed to Test Step 7.Test Step 3. Check the "Load Signal" Wiring for a Short Circuit
Disconnect the P1 connector.
Disconnect the "load signal" wires from the power sensor.
Check for continuity between P1-25 and all the other terminals on the P1 connector.
Check for continuity between P1-19 and all the other terminals on the P1 connector. Expected Result:Each continuity check indicates an open circuit.Results:
OK - Each continuity check indicates an open circuit. The "load signal" wiring does not have a short circuit.Repair: Connect the P1 connector and the P3 connector. Connect the "load signal" wires to the power sensor. Be sure to observe the correct polarity.Proceed to Test Step 4.
Not OK - At least one continuity check indicates a short circuit.Repair: Repair the harness or the connection, when possible. Replace parts, if necessary. Verify that the problem is resolved.STOPTest Step 4. Check the "Load Signal" Wiring for ContinuityNote: A potentiometer may be installed in the "load signal" wiring. A high resistance reading may be caused by the potentiometer.
Check the continuity of the wiring between P1-25 and the power sensor.
Check the continuity of the wiring between P3-16 and the power sensor.
Check the continuity of the wiring between P1-19 and the power sensor.
Check the continuity of the wiring between P3-3 and the power sensor. Expected Result:The "load signal" wiring has continuity.Results:
OK - The "load signal" wiring has continuity. Proceed to Test Step 5.
Not OK - The "load signal" wiring has an open circuit. The open circuit may be in a wire, in a connector, or in the potentiometer (if equipped).Repair: Repair the component, when possible. Replace parts, if necessary. Verify that the original problem is resolved.STOPTest Step 5. Check the Power Sensor, the Potential Transformers, and the Current TransformersVerify that the power sensor, the potential transformers, and the current transformers are operating correctly. Refer to the appropriate service literature for the components.Expected Result:The components are operating correctly.Results:
OK - The components are operating correctly. Proceed to Test Step 12.
Not OK - At least one of the components is not operating correctly.Repair: Repair the component, when possible. Replace the component, if necessary. Verify that the original problem is resolved.STOPTest Step 6. Check the Continuity of the Cat Data Link
Disconnect Cat ET from the service tool connector.
Disconnect the wiring for the Cat Data Link from the GSC+.
Disconnect the P1 connector from the ECM.
Measure the resistance between the points that are listed in Table 1. During each measurement, wiggle the wires in the harness in order to check for an intermittent problem. Be sure to wiggle the wires near each of the connectors.
Table 1
Resistance Measurements for the Cat Data Link
Connector and Terminal Connector and Terminal
P1-8 Terminal 19 on the GSC+
P1-9 Terminal 20 on the GSC+
P1-8 Ground strap for the ECM
P1-9 Ground strap for the ECM Expected Result:Each check of the resistance between the terminals is less than five Ohms.Each check of the resistance between the terminals and the ground strap is greater than five Ohms.Results:
OK - Each check of the resistance for the Cat Data Link is within the specification. The wiring for the Cat Data Link appears to be OK.Repair: Perform the following procedure:
Connect the