3T5-10302-0 Tohatsu PLATE, FUEL INJECTOR

Illustration 1 g01254431
Schematic for the starting aid switch
Test Step 1. Check the Status of the "Starting Aid On/Off Switch"
Turn the keyswitch to the OFF position.
Connect Caterpillar Electronic Technician (ET) to the service tool connector.
Turn the keyswitch to the ON position.
Monitor the status for the "Starting Aid On/Off Switch" while the starting aid switch is toggled to the ON position and the OFF position. The correct status for the "Starting Aid On/Off Switch" is "On" when the switch is in the ON position. The correct status for the "Starting Aid On/Off Switch" is "Off" when the switch is in the OFF position.Note: If the status for the "Starting Aid On/Off Switch" indicates "Not Installed", then the "Starting Aid On/Off Switch" parameter has not been programmed.
Turn the keyswitch to the OFF position. Expected Result:Cat ET is reporting the correct status for the switch.Results:
OK - Cat ET is reporting the correct status for the switch.Repair: The starting aid switch appears to operating correctly at this time. There may be an intermittent electrical problem in the harness or in a connector. If an intermittent problem is suspected, refer to Troubleshooting, "Electrical Connectors - Inspect" for information that is related to troubleshooting intermittent electrical problems.STOP
Not OK - Cat ET is not reporting the correct status for the switch. The ECM is not reading the change in switch status. Proceed to Test Step 2.Test Step 2. Inspect the Electrical Connectors and the Wiring
Illustration 2 g01186024
Location of the J1/P1 ECM connectors (typical left side engine view)
Thoroughly inspect the J1/P1 ECM connector, the connectors, and the firewall bulkhead connectors. Refer to Troubleshooting, "Electrical Connectors - Inspect" for details.
Illustration 3 g01253945
Terminal locations at the P1 ECM connector for the fan override switch
(P1-5) AP sensor/switch sensor return
(P1-6) Input No. 6
(P1-7) Input No. 4
(P1-46) Input No. 7
(P1-47) Input No. 5
Perform a 45 N (10 lb) pull test on each of the wires in the ECM connector that are associated with the suspect switch circuit.
Check the allen head screw for each of the ECM connectors for the proper torque. Refer to Troubleshooting, "Electrical Connectors - Inspect" for the correct torque values.
Check the harness and the wiring for abrasion and pinch points from the battery to the ECM. Then, check the wiring from the keyswitch 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 or of pinch points.Results:
OK - The harness and connectors appear to be OK. Proceed to Test Step 3.
Not OK - There is a problem with 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 3. Create a Short Circuit at the Switch
Fabricate a jumper wire that is long enough to create a short circuit across the terminals at the harness connector for the starting aid switch.
Disconnect the switch from the harness.
Install the jumper wire across the two switch terminals at the harness connector for the starting aid switch.
Turn the keyswitch to the ON position.
Use Cat ET to monitor the status of the "Starting Aid On/Off Switch". While the status for the "Starting Aid On/Off Switch" is monitored, remove the jumper wire and then insert the jumper wire. The correct status for the "Starting Aid On/Off Switch" is "On" when the jumper wire is inserted. The correct status for the "Starting Aid On/Off Switch" is "Off" when the jumper wire is removed.
Turn the keyswitch to the OFF position. Expected Result:Cat ET is reporting the correct status for the switch.Results:
OK - Cat ET is reporting the correct status.Repair: The wiring harness and the ECM are OK. There is a problem with the switch. Replace the starting aid switch. Verify that the repair eliminates the problem.STOP
Not OK - Cat ET does not report the correct status. There is a problem in the wire harness between the starting aid switch and the ECM. There may be a problem with the ECM. Restore the wiring to the original configuration. Proceed to Test Step 4.Test Step 4. Check for Proper Operation of the ECM
Disconnect the J1/P1 ECM connectors.
Fabricate two jumper wires that are long enough to create a test circuit at the ECM connector. Crimp a connector socket to one end of each of the jumper wires.
Remove the wire from the terminal location at the P1 ECM connector that is the input for the starting aid switch. Also, remove the wire from terminal location P1-5 (AP sensor/switch sensor return). Install one of the jumper wires into each of these terminal locations.
Turn the keyswitch to the ON position.
Monitor the status of the "Starting Aid On/Off Switch" while you short the loose ends of the jumper wires. Provide an open circuit for the loose ends of the jumper wires. Recheck the switch status. The correct status for the "Starting Aid On/Off Switch" is "On" when the jumper wires are shorted together. The correct status for the "Starting Aid On/Off Switch" is "Off" when the jumper wires are open.
Turn the keyswitch to the OFF position.
Restore all wiring to the original configuration. Expected Result:Cat ET is reporting the correct status for the switch.Results:
OK - Cat ET is reporting the correct status for the switch.Repair: The ECM is functioning properly at this time. There is a problem in the OEM wiring harness that is between the ECM connector and the starting aid switch. Repair the circuit or send the vehicle to the OEM dealer for repairs.STOP
Not OK - Cat ET does not report the correct status for the switch. Repair: The ECM is not reading the switch input properly. There is a problem with the ECM. Perform the following procedure:
Temporarily connect a test ECM. Refer to Troubleshooting, "Replacing the ECM".
Recheck the circuit