TUBE AS-FUEL SUPPLY 3447865 - Caterpillar

Illustration 6 g00704301
ECM engine harness connector P2
Turn the keyswitch to the OFF position.
Disconnect the connector for the ECM harness. Thoroughly inspect both halves of the connector for signs of corrosion or moisture.
Turn the keyswitch to the ON position. Monitor the "Active Diagnostic Code" screen. Wait at least 15 seconds for activation of the code.An open circuit diagnostic code should be active for the suspect sensor.Note: When the engine harness is disconnected, all of the open circuit diagnostic codes for the pressure sensors will be active. This is normal. Disregard the diagnostic codes for the pressure sensors.
Turn the keyswitch to the OFF position.
Fabricate a jumper wire 150 mm (6 inch) long. Crimp a Deutsch socket to both ends of the wire.
Install the jumper wire on the ECM Pin terminal. Insert the jumper wire between the terminal for the suspect sensor signal and the common connection for the engine temperature sensor (terminal 18).A short circuit diagnostic code should be active when the jumper wire is installed.Note: If access to the ECM connector is limited, it may be helpful to connect a 70-Termial Breakout T to the ECM Connector. This will allow the jumper wire to be inserted into the Breakout T. Ensure that the jumper wire is inserted into the Breakout T and that the full wiring harness is attached.Refer to Illustration 6 for the engine harness connector P2.Expected Result:Open circuit diagnostic codes are active when the jumper is removed. Short circuit diagnostic codes are active when the jumper is installed. Results:
OK - The ECM is working properly. Proceed to Test Step 8.
Not OK - One of the following conditions exists: The open circuit diagnostic code is not active when the harness is disconnected. The short circuit diagnostic code is not active when the jumper wire is installed.Repair: Perform the following repair:
Temporarily connect a test ECM.
Remove all jumpers and replace all connectors.
Recheck the system for active diagnostic codes.
Repeat the test step.
If the problem is resolved with the test ECM, reconnect the suspect ECM.
If the problem returns with the suspect ECM, replace the ECM.
Verify that the repair eliminates the problem. Stop.Test Step 8. Bypass The Harness Wiring Between The ECM And The Sensor Connector.
Turn the keyswitch to the OFF position.
Disconnect the connector for the ECM harness, and the sensor connector.
Remove the sensor signal wire from the ECM connector.
Remove the signal wire (terminal 1) from the sensor connector on the engine harness.
Fabricate a jumper wire that is long enough to reach from the ECM to the sensor connector with Deutsch sockets on both ends.
Insert one end of the jumper into the ECM connector. Insert the other end of the jumper into the sensor connector of the engine harness.
Reconnect the connector for the ECM harness and the sensor connector.
Turn the keyswitch to the ON position.
Monitor the "Active Diagnostic Code" screen on Cat ET for either the open circuit diagnostic code for the sensor or the short circuit diagnostic code for the sensor.Expected Result:The diagnostic code disappears when the jumper is installed.Results:
OK - There is