SHOE-TRACK 2747839 - Caterpillar

Illustration 9 g01424907
Terminal locations for the CAN data link at the NOX sensor buffer (Terminal 3) CAN Data Link − (Terminal 4) CAN Data Link +
Illustration 10 g01424780
Terminal locations at the connector for the termination resistor that are associated with the CAN data link (Terminal 1) CAN data link + (Terminal 3) CAN shield (Terminal 4) CAN data link −
Perform a 45 N (10 lb) pull test on each of the wires that are associated with the CAN data link.
Check the allen head screw on each ECM connector and on the customer connector for the proper torque. Refer to Troubleshooting, "Electrical Connectors - Inspect" for the correct torque values.
Check the wiring harnesses for abrasion, for corrosion 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 appear to be OK. Proceed to Test Step 2.
Not OK - There is a problem in the wiring harness.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 problem is resolved.STOPTest Step 2. Verify the Proper Installation of the Termination Resistors
Remove the electrical power from the ECM.
Disconnect the following components from the data link:
ECM at the P1 ECM connector
Bypass valve actuator
NOX sensor buffer
Optional display panel
Throttle actuatorDo not disconnect the fuel metering valve from the data link.Note: Wiggle the harness during the following measurements in order to reveal an intermittent condition.
Measure the resistance between terminals P1-50 (CAN data link +) and P1-34 (CAN data link -).Expected Result:The resistance is between 57 and 63 Ohms.Results:
OK - The resistance is between 57 and 63 Ohms. Proceed to Test Step 3.
Not OK - The resistance is between 114 Ohms and 126 Ohms. Repair: A termination resistor is missing. One resistor must be located on each end of the data link. Verify that the termination resistor that is in the terminal box for the master ECM is connected to the data link. The other termination resistor is an internal resistance that is located in the fuel metering valve. Ensure that the harness connector is connected to the fuel metering valve. Ensure that the jumper wire that is used to enable the internal resistance is connected between terminals P and R at the harness connector for the fuel metering valve.Refer to the appropriate Electrical Schematic in order to determine the missing resistor. Replace the missing resistor. Restore the wiring to the original configuration. Verify that the problem is resolved.STOP
Not OK - The resistance is less than 57 Ohms. There may be a short circuit in the harness. Leave the jumper wires in place. Proceed to Test Step 3.
Not OK - The resistance is greater than 126 Ohms. There may be an open circuit in the harness. Leave the jumper wires in place. Proceed to Test Step 4.Test Step 3. Check the Harness for a Short