3B2B64515-1 Tohatsu PROPELLER (7.5), 3 X 8.5 X 7.5

Table 1
Diagnostic Codes Table
Description Conditions which Generate this Code System Response
E043(1) Low System Voltage The battery voltage to the ECM is less than normal. The code is logged.
168-0 Electrical System Voltage high The battery supply voltage is greater than 32 VDC for two seconds.
The engine's ECM has been powered for three seconds.
The engine is not being cranked.
168-1 Electrical System Voltage low The battery supply voltage is less than 9 VDC for two seconds.
The engine's ECM has been powered for three seconds.
The engine is not being cranked.
168-2 Electrical System Voltage erratic, intermittent, or incorrect The engine is running. The battery voltage falls below 9 VDC for at least .06 seconds. The voltage returns above 9 VDC.
or
Three voltage readings in the last seven seconds were below 9 VDC. To reduce resistance in the wiring harness, there are two isolated power connections to the ECM. The connections must be complete in order to ensure proper engine operation. There may always be a constant power supply to the ECM when the locomotive engine is shutdown. In order to shut off the power to the ECM, the breaker for the ECM must be turned to the OFF position or the battery power needs to be disconnected.The engine will begin the start-up when the following conditions exist:
The ECM detects the input voltage at the input for the keyswitch.
The emergency stop switch is not activated.
The start/run/stop switch is in the RUN position.Note: Use an isolation transformer between the battery and the ECM in order to protect the ECM against a voltage spike or a ground loop.An emergency stop push button and a start/run/stop switch are provided in the junction box.The customer can install multiple start/run/stop switches(push button) and emergency stop push buttons. When the start/run/stop switches are activated the inputs to the ECM from the start/run/stop switches go low.When the emergency stop push button is activated, the emergency stop inputs float high. The fuel supply to the injectors will be cut off and the air shutoff relays will be activated.
Illustration 1 g01314139
Typical schematic
Illustration 2 g01258369
P1 ECM connector
(P1-52) +Battery
(P1-53) +Battery
(P1-63) −Battery
(P1-65) −Battery
(P1-70) "ECM reset switch" (Keyswitch)
Illustration 3 g01258374
Connector "A"
(Terminal 7) +Battery
(Terminal 9) +Battery
(Terminal 11) −Battery
(Terminal 13) −Battery
Illustration 4 g01258377
Connector "B"
(Terminal 13) "ECM reset switch" (Keyswitch)
Illustration 5 g01258378
Connector "F"
(Terminal 2) −Battery
(Terminal 6) +Battery
Illustration 6 g01234146
Location of ECM connectors
Test Step 1. INSPECT ELECTRICAL CONNECTORS AND WIRING
Turn the breaker for the ECM to the OFF position.
Thoroughly inspect the ECM connectors J1/P1. Inspect all of the other connectors in the circuit. Refer to Troubleshooting, "Inspecting Electrical Connectors" for the proper procedure for inspecting system wiring.
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. Refer to Troubleshooting, "Inspecting Electrical Connectors" for details.
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. The harness and wiring are free of corrosion, of abrasion, and of pinch points.Results:
OK - The harness and wiring are OK. 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 THE BATTERY VOLTAGE
Measure no-load voltage at the battery posts. Refer to Systems Operation/Testing and Adjusting for the proper procedures to check the batteries.
Load test the batteries. Use the 4C-4911 Battery Load Tester. Refer to the Operating Manual, SEHS9249. Refer to Special Instruction, SEHS7633. Expected Result:The no-load voltage at the batteries is at least 23.5 VDC, and the batteries pass the load test.Results:
OK - The no-load voltage at the batteries is at least 23.5 VDC, and the batteries pass the load test. Proceed to Test Step 3.
Not OK - The no-load voltage at the batteries is less than 23.5 VDC, and/or the batteries fail the load test.Repair: The batteries or the alternator are causing the problem. Recharge the batteries or replace the batteries. Verify that the original condition is resolved. Refer to Systems Operation/Testing and Adjusting for information on the charging system.STOPTest Step 3. CHECK THE VOLTAGE AT THE ECM CONNECTOR
Disconnect the J1/P1 ECM connector.
Turn the breaker for the ECM to the ON position.
Wiggle the harness during the following test steps in order to find an intermittent condition.
Measure the voltage between P1-52 (positive battery) and P1-63 (negative battery).
Measure the voltage between P1-53 (positive battery) and P1-65 (negative battery).
Measure the voltage between P1-70 (ECM reset) and P1-65 (negative battery).
Turn the breaker for the ECM to the OFF position. Expected Result:The voltage is 1 VDC from the voltage at the battery terminals.Results:
OK - The ECM is receiving the correct voltage.Repair: If