0511850 JOHNSON CONNECTOR

Illustration 1 g01344091
Typical schematic
Illustration 2 g01277442
P1 ECM connector (P1-21) Start/Run/Stop input (P1-22) Start/Run/Stop input
Illustration 3 g01248709
Connector for the user interface panel (Terminal 36) Start/Run/Stop input
Illustration 4 g01234146
Location of ECM connectorsTest Step 1. Inspect Electrical Connectors and Wiring
Turn the local/remote switch on the control panel to the OFF/RESET position.
Thoroughly inspect the ECM connectors J1/P1. Inspect all of the other connectors. 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 Signal for the Start/Run/Stop Input on Caterpillar Electronic Technician (ET)
Connect Cat ET.
Turn the local/remote switch on the control panel to the LOCAL position.
Turn the fuel control switch to the ON position.
Use Cat ET in order to check if fuel injection is disabled.Note: Cat ET will not display fuel injection if fuel injection is enabled. Cat ET will only display fuel injection if fuel injection is disabled.
Turn the fuel control switch to the OFF position.
Use Cat ET in order to check if fuel injection is disabled.Expected Result:Fuel injection is enabled when the fuel control switch is in the ON position. Fuel injection is disabled when the fuel control switch is in the OFF position.Results:
OK - The status for the fuel injection is correct. The circuit for the start/run/stop input is functioning correctly.Repair: The problem may be intermittent. If the problem is intermittent, refer to Troubleshooting, "Inspecting Electrical Connectors".STOP
Not OK - The status for the fuel injection is incorrect. Proceed to Test Step 3.Test Step 3. Check the Signal for the Start/Run/Stop Input from the User Interface Panel to the ECM
Locate the connector for the user interface panel on the user interface panel. Refer to Illustration 1 in order to identify the configuration of the wiring.
Remove the wire to terminal 36 of the connector on the outside of the user interface panel. Make sure that the wire is isolated from engine ground and from other wires in the harness.
Use Cat ET in order to check if fuel injection is disabled.Note: Cat ET will not display fuel injection if fuel injection is enabled. Cat ET will only display fuel injection if fuel injection is disabled.
Connect a wire jumper between engine ground and the wire that was removed in the previous test step.
Use Cat ET in order to check if fuel injection is disabled.
Return all wires to the original configuration.Expected Result:Fuel injection is enabled when the wire is shorted to engine ground. Fuel injection is disabled when the wire is isolated from engine ground and other wires in the harness.Results:
OK - Fuel injection is enabled when the wire is shorted to engine ground. Fuel injection is disabled when the wire is isolated from engine ground and other wires in the harness. The wiring between the ECM and the user interface panel is OK. Proceed to Test Step 4.
Not OK - The status for the fuel injection is incorrect. Proceed to Test Step 5.Test Step 4. Check the Signal for the Start/Run/Stop Input to the User Interface Panel
Locate the terminal TBX34 or connector terminal C1-36 in the user interface panel. Refer to Illustration 1 in order to identify the configuration of the wiring.
Remove the wire from terminal TBX34 that goes to the connector for the user interface panel or remove the wire from terminal AC-36. Make sure that the wire is isolated from engine ground and other wires in the harness.
Use Cat ET in order to check if fuel injection is disabled.Note: Cat ET will not display fuel injection if fuel injection is enabled. Cat ET will only display fuel injection if fuel injection is disabled.
Connect a wire jumper between engine ground and the wire that was removed in the previous test step.
Use Cat ET in order to check if fuel injection is disabled.
Return all wires to the original configuration.Expected Result:Fuel injection is enabled when the wire is shorted to engine ground. Fuel injection is disabled when the wire is isolated from engine ground and from other wires in the harness.Results:
OK - Fuel injection is enabled when the wire is shorted to engine ground. Fuel injection is disabled when the wire is isolated from engine ground and from other wires in the harness.Repair: The problem is in the wiring and/or connectors for the start/run/stop input between the user interface panel and the control panel. Use continuity checks in order to find the open or short in the circuitry.STOP
Not OK - The status for the fuel injection is incorrect.Repair: The problem is in the wiring in the user interface panel. Repair the wiring and/or the connectors.STOPTest Step 5. Check the ECM
Fabricate jumper wires that can be used in place of the signal wires in the ECM connector for the start/run/stop inputs. Crimp a connector socket to one end of the jumper wires.
Disconnect the J1/P1 ECM connector.
Remove the wires in P1-21 and P1-22 for the start/run/stop inputs.
Install the jumper wires into the terminal location for the start/run/stop inputs at the ECM connector. Make sure that the wires are isolated from engine ground and from other wires in the harness.
Connect t