3V2-03179-0 Tohatsu STOP SCREW

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Schematic for the digital sensor supply
Test Step 1. Inspect the Electrical Connectors and the Wiring
Remove electrical power from the ECM.
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ECM connectors (typical example)
(1) J1/P1 ECM connector
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Customer connector (typical example)
(2) P61 Customer connector
Thoroughly inspect connectors (1) and (2). Inspect the connectors for each digital sensor. Refer to Troubleshooting, "Electrical Connectors - Inspect".
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P1 ECM connector
(P1-3) Sensor return
(P1-4) +8 V digital supply
(P1-46) Coolant level
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Terminal locations at the P61 customer connector
(P61-8) +8 V digital supply
(P61-15) Sensor return
(P61-36) Coolant level
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Sensor connector
(Terminal A) +5 V supply
(Terminal B) Sensor return
(Terminal C) Sensor signal
Perform a 45 N (10 lb) pull test on each of the wires that are associated with the digital sensor supply.
Check the allen head screw on the ECM connectors and the customer connector for the proper torque. Refer to Troubleshooting, "Electrical Connectors - Inspect" for the correct torque values.
Check the harness and wiring for abrasions and for pinch points from the battery to the ECM. Expected Result:All connectors, pins, and sockets are completely coupled and/or inserted, and the harness and wiring are free of corrosion, of abrasion, and of pinch points.Results:
OK - The connectors and wiring are okay. Proceed to Test Step 2.
Not OK - There is a problem in the connectors and/or wiring.Repair: Repair the connectors or wiring and/or replace the connectors or wiring. Ensure that all of the seals are properly in place and ensure that the connectors are completely coupled. Verify that the repair eliminates the problem.STOPTest Step 2. Check for Active Diagnostic Codes
Connect the Caterpillar Electronic Technician (ET) to the service tool connector. Refer to Troubleshooting, "Electronic Service Tools".
Restore electrical power to the ECM.
Monitor the active diagnostic code screen on Cat ET. Check for an active 41-03 code and an active 41-04 code. Note: Wait at least 30 seconds in order for the diagnostic codes to become active.Expected Result:No diagnostic codes are active.Results:
OK - No diagnostic codes are active.Repair: If any of the above codes are logged and the engine is not running properly, refer to Troubleshooting, "Troubleshooting Without a Diagnostic Code".If the engine is running properly at this time, there may be an intermittent problem in a harness that is causing the codes to be logged. Refer to Troubleshooting, "Electrical Connectors - Inspect".STOP
Not OK - Either the 41-03 or 41-04 diagnostic code is active at this time. Proceed to Test Step 3.Test Step 3. Disconnect the Digital Sensor and Check for Active Diagnostic Codes
Disconnect the engine coolant level sensor at the harness connector.
Monitor the active diagnostic code screen on Cat ET while you disconnect the sensor connector. Check for an active 41-03 code or an active 41-04 code. Note: Wait at least 30 seconds in order for the diagnostic codes to become active.
Remove electrical power from the ECM. Expected Result:The 41-04 diagnostic code deactivates when the engine coolant level sensor is disconnected.Results:
OK - The 41-04 diagnostic code deactivates when the sensor is disconnected.Repair: Connect the sensor. If the diagnostic code returns, replace the sensor.Verify that the problem is resolved.STOP
Not OK - The 41-04 diagnostic code remains after the coolant level sensor is disconnected. Leave the sensor disconnected. Proceed to Test Step 4.Test Step 4. Check the Supply Voltage at the ECM
Disconnect the J1/P1 ECM connectors.
Fabricate two jumper wires that are long enough to be used as test leads at the ECM connectors. Crimp connector sockets to one end of each jumper wire.
Remove the wires from terminal locations P1-4 (+8 V digital supply) and P1-3 (sensor return). Install a jumper wire into each of these terminal locations.
Connect the P1 ECM connector.
Restore electrical power to the ECM.
Measure the voltage between the wire jumpers in P1-4 (+8 V digital supply) and P1-3 (sensor return).
Remove electrical power from the ECM.
Replace all wires to the original configuration. Expected Result:The voltage measurement is 8.0 0.4 VDC.Results:
OK - The voltage measurement is 8.0 0.4 VDC.Repair: The ECM is operating correctly. The supply wires are shorted to another wire in the harness or the supply wires are shorted to engine ground. Repair the wiring and/or the connector. Replace parts, if necessary. Verify that the problem is resolved.STOP
Not OK - The voltage measurement is not 8.0 0.4 VDC.Repair: There is a problem with the ECM. Replace the ECM. Refer to Troubleshooting, "Replacing the ECM".STOP