HARNESS AS 4667500 - Caterpillar

Test Step 7. Create a Short Circuit Between the Signal and the Common Terminals at the Sensor Connector
Turn the keyswitch to the ON position.
Fabricate a jumper wire that is 150 mm (6 inch) long. Crimp a terminal to both ends of the wire.
Monitor the "Active Diagnostic Code" screen of the electronic service tool before installing the jumper wire and after installing the jumper wire.
Install the jumper on the sensor connector. Install one end of the jumper at the sensor signal (terminal 3). Install the other end of the jumper at the common connection for the pressure sensor (terminal 2). Wait at least 30 seconds for activation of the short circuit diagnostic code.
Record the result of the test.Expected Result:A 1797-4 diagnostic code is active when the jumper is installed. A 1797-3 diagnostic code is active when the jumper is removed.Results:OK - The engine harness and the ECM are OK.Repair: Perform the following repair:
Temporarily connect a new sensor to the harness but do not install the new sensor in the engine.
Use the electronic service tool to verify that the replacement sensor eliminates the fault.
If the 1797-3 diagnostic code is eliminated, install the replacement sensor.
Use the electronic service tool to clear the logged diagnostic codes.STOP.Not OK - The 1797-3 diagnostic code remains active when the jumper is installed. The most probable location for the open circuit is in the common wire for the sensor, or in the sensor signal wire of the engine harness between the ECM and the sensor. Remove the jumper. Proceed to Test Step 8.Test Step 8. Check the Operation of the ECM by Creating Open and Short Circuits at the ECM Connector
Turn the keyswitch to the OFF position.
Disconnect the P2 connector from the ECM. Thoroughly inspect both halves of the connector for signs of corrosion or moisture. Refer to Troubleshooting, "Electrical Connectors - Inspect".
Reconnect the P2 connector.
Turn the keyswitch to the ON position. Use the electronic service tool in order to monitor the "Active Diagnostic Code" screen. Wait at least 10 seconds for activation of the code.A 1797-3 diagnostic code should be active for the suspect sensor.Note: When the P2 connector is disconnected, all of the open circuit diagnostic codes for the pressure sensors and temperature sensors will be active. This is normal. Disregard the diagnostic codes for the pressure sensors and the temperature sensors that are not suspect. Address the diagnostic codes for the fuel rail pressure sensor only.
Turn the keyswitch to the OFF position.
Fabricate a jumper wire that is 150 mm (6 inch) long. Crimp a terminal to both ends of the wire.
Install the jumper wire on the P2 connector. Insert the jumper wire between P2:51 and P2:40.Use the electronic service tool to verify that there is a 1797-4 diagnostic code.
Record the result of the test.Expected Result:A 1797-3 diagnostic code is present when the jumper is removed. A 1797-4 diagnostic code is present when the jumper is installed.Results:OK - The ECM is operating correctly. Proceed to Test Step 9.Not OK - One of the following