3T9B76009-0 Tohatsu BAND, STARTER MOTOR

Illustration 1 g01136632
Schematic for digital sensor supply
The connection of any electrical equipment and the disconnection of any electrical equipment may cause an explosion hazard which may result in injury or death. Do not connect any electrical equipment or disconnect any electrical equipment in an explosive atmosphere.
Test Step 1. Inspect the Electrical Connectors and the Wiring
Turn the keyswitch to the OFF position.
Illustration 2 g01136484
Top view (1) P1 ECM connector (2) P2 ECM connector (3) P3 Customer connetor
Thoroughly inspect connectors (1), (2), and (3). Also inspect the connectors for the auxiliary temperature sensor and the coolant level sensor. Refer to Troubleshooting, "Electrical Connectors - Inspect".
Illustration 3 g01136655
P1 ECM connector (P1-24) Coolant level (P1-29) Digital return (P1-30) Analog return (P1-35) +8 V supply
Illustration 4 g01136469
P2 ECM connector (P2-25) Auxiliary temperature sensor
Illustration 5 g01136657
J3 and P3 connectors (8) +8 V supply (9) Digital return (11) Auxiliary temperature sensor (30) Analog return (30) Coolant level
Perform a 45 N (10 lb) pull test on each of the wires that is associated with the auxiliary temperature sensor circuit and with the coolant level sensor.
Check the torque of the allen head screws for the ECM connectors and the customer connector. Refer to Troubleshooting, "Electrical Connectors - Inspect" for the correct torque values.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 in good repair. Proceed to Test Step 2.
Not OK - There is a problem with the connectors and/or wiring.Repair: Repair the wiring and connectors or replace the wiring and the connectors. Ensure that the seals are correctly installed on each of the connectors. 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".
Turn the keyswitch to the ON position.
Observe the active diagnostic code screen on Cat ET. Wait at least 15 seconds so that any codes may become active. Look for these codes:
263-03
263-04 Expected Result:One of the above diagnostic codes is active:Results:
Active 263-03 code - A 263-03 diagnostic code is active. Proceed to Test Step 3.
Active 263-04 code - A 263-04 diagnostic code is active. Proceed to Test Step 4.
No active codes - None of the above 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".STOPTest Step 3. Check the Sensor Supply Voltage at the Sensor Connectors
Turn the keyswitch to the OFF position.
Disconnect all of the following digital sensors at the sensor connector:
Coolant level sensor J34/P34
Auxiliary temperature sensor J114/P114
Turn the keyswitch to the ON position.
Measure the voltage between terminal A and terminal B at the sensor connectors.Expected Result:The voltage is 8.0 0.4 VDC at each of the sensor connectors.Results:
OK - The supply voltage is reaching the sensor.Repair: Connect all of the sensor connectors. Clear all diagnostic codes. Check for active diagnostic codes. If the problem is intermittent, refer to Troubleshooting, "Electrical Connectors - Inspect".STOP
Not OK - At least one voltage measurement is not 8.0 0.4 VDC. There is a problem with the wiring or with the ECM. Proceed to Test Step 5.Test Step 4. Disconnect the +8 V Digital Sensors and Check for Active Diagnostic Codes
Disconnect the following sensors one at a time:
Engine coolant level
Auxiliary temperature
Wait for 15 seconds after you disconnect each sensor. Check if the 263-04 diagnostic code has deactivated.Expected Result:The 263-04 diagnostic code deactivates when a particular sensor is disconnected.Results:
OK - The 263-04 diagnostic code deactivates when a particular sensor is disconnected.Repair: Connect the suspect sensor. If the diagnostic code returns, replace the sensor.Connect all of the connectors. Verify that the problem is resolved.STOP
Not OK - The 263-04 diagnostic code remains after all of the sensors are disconnected. Leave the sensors disconnected. Proceed to Test Step 5.Test Step 5. Check the +8 V Supply Wire for a Short Circuit
Turn the keyswitch to the OFF position.
Disconnect the J1/P1 and J2/P2 ECM connectors.
Verify that all of the digital sensors are disconnected.Note: Wiggle the harness during the following measurements in order to reveal any intermittent short condition.
Measure the resistance between P1-35 (+8 VDC supply) and the remaining terminals on the P1 and P2 connectors.