F321756 Force PACKING

Illustration 1 g03858750
Schematic for the throttle inputsTest Step 1. Inspect the Electrical Connectors and the Wiring
Turn the keyswitch to the OFF position.
Illustration 2 g01183529
Location of the J1/P1 ECM connector (typical left side engine view)
Thoroughly inspect the J1/P1 ECM connector and the connector for the throttle switch. Refer to Troubleshooting, "Electrical Connectors - Inspect" for details.
Perform a 45 N (10 lb) pull test on each of the wires in the connectors that are associated with the circuit.
Check the torque of the allen head screws for each of the ECM connectors. Refer to Troubleshooting, "Electrical Connectors - Inspect" for the correct torque values.
Check the harness and wiring for corrosion, for abrasion, and for pinch points back to the ECM.Expected Result:All connectors, pins, and sockets are completely inserted and coupled. The harness and wiring are free of corrosion, of abrasion, and of pinch points.Results:
Not OK - There is a problem with the wiring and/or the connectors.Repair: Repair the connectors and/or the wiring. Replace parts, if necessary. 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 Status of the Throttle Inputs
Turn the keyswitch to the OFF position.
Connect the Caterpillar Electronic Technician (ET) to the service tool connector.
Turn the keyswitch to the ON position.
Observe the status of the throttle inputs on Cat ET while you operate the throttle switch in each position.
Table 1
Throttle Input    Neutral    High "Rabbit"    Low "Tortoise"    
"#1 (Low)"     Off     Off     On    
"#2 (Low Par)"     On     Off     On    
"#3 (High)"     Off     On     Off    
"#4 (High Par)"     On     On     Off    Expected Result:The status of the throttle switch corresponds with the table above.Results:
OK - The throttle switch is functioning properly at this time.Repair: The problem appears to be resolved. The problem is probably related to a faulty connection in the harness or at a connector. Carefully inspect the connectors and the wiring that is related to the start circuit. Ensure that all connections are tight and ensure that all wires are crimped correctly. Refer to Troubleshooting, "Electrical Connectors - Inspect" for information that relates to the proper troubleshooting of intermittent electrical problems.STOP
Not OK - One or more of the throttle switch inputs are incorrect. Record the suspect input. Proceed to Test Step 3.Test Step 3. Short the Wires at the Throttle Switch
Turn the keyswitch to the OFF position.
Disconnect the connector for the throttle switch.
Observe the status of the suspect throttle input on Cat ET.
Fabricate a jumper wire that is long enough to connect across two terminals of the connector for the throttle switch. Crimp a connector pin to each end of the jumper wire.
Use the jumper wire to short terminal 1 (digital return) to the terminal for the suspect throttle input on the harness side of the connector for the throttle switch.
Observe the status of the suspect throttle input on Cat ET.
Remove the jumper wire.Expected Result:The correct status of the suspect throttle input is "Off" when the connector for the throttle switch is disconnected. The correct status is "On" when the jumper wire is installed.Results:
OK - The harness and the ECM are OK.Repair: The problem is in the throttle switch. Replace the throttle switch. Verify that the repair eliminates the problem.STOP
Not OK - The switch status does not change when the jumper wire is installed. The problem appears to be in the harness or in the ECM. Proceed to Test Step 4.Test Step 4. Short the Wires at the ECM
Ensure that the keyswitch is in the OFF position.
Disconnect the J1/P1 ECM connectors.
Fabricate a jumper wire that is long enough to connect across the terminals at the ECM connector. Crimp connector sockets to each end of the jumper wire.
Remove terminal P1-5 (return) and the terminal of the suspect throttle input from the ECM connector. Install the jumper wire into these terminal locations.
Connect the J1/P1 ECM connectors.
Turn the keyswitch to the ON position.
Observe the status of the suspect throttle input on Cat ET.
Turn the keyswitch to the OFF position.
Disconnect the J1/P1 ECM connector and remove the jumper wire. Connect the J1/P1 ECM connectors.
Turn the keyswitch to the ON position.
Observe the status of the suspect throttle input on Cat ET.Expected Result:The correct status of the suspect throttle input is "On" when the jumper wire is installed. The status is "Off" when the jumper wire is removed.Results:
OK - The status of the throttle input is correct.Repair: There is a problem in the harness wiring between the ECM and the throttle switch. Repair the harness. Replace the harness, if necessary. Verify that the repair eliminates the problem.STOP
Not OK - The status of the throttle input is not correct.Repair: The ECM is not responding to the switch inputs. Replace the ECM. Refer to Troubleshooting, "Replacing the ECM" for information that relates to replacement of the ECM.STOP