921503-6430 Nissan SCREW

Illustration 1 g01065141
Schematic of the Cat Data Link
The engine is not equipped with an ASM.
Illustration 2 g01302275
Schematic of the Cat Data Link
The engine is equipped with an ASM.
Test Step 1. INSPECT THE ELECTRICAL CONNECTORS AND WIRING
Remove the electrical power from the engine. Note: For the following steps, refer to Troubleshooting, "Electrical Connectors - Inspect".
Thoroughly inspect each of the following connectors:
J1/P1 connectors
J3/P3 connectors
J5/P5, J6 and J9/P9 connectors
14-pin connectors for the ITSM
Check the torque of the allen head screw for the ECM connectors. refer to Troubleshooting, "ECM - Replace" for the correct torque value.
Perform a 45 N (10 lb) pull test on each of the wires that are associated with the circuit for the data link.
Check the harnesses and wiring for abrasion and for pinch points. Expected Result:The connectors, pins, and sockets are connected properly. The connectors and the wiring do not have corrosion, abrasion, or pinch points.Results:
OK - The components are in good condition with proper connections. Proceed to Test Step 2.
Not OK - The components are not in good condition and/or at least one connection is improper.Repair: Perform the necessary repairs and/or replace parts, if necessary.STOPTest Step 2. CHECK THE DATA LINK
Connect Cat ET to the service tool connector. Refer to Troubleshooting, "Electronic Service Tools".
Restore the electrical power to the engine. Set the engine control to the STOP mode.
Select the "File/Select ECM" menu on the Cat ET. Verify that all of the modules are displayed on the "ECM Selector" screen. Verify that the following diagnostic codes are not activated.
590-9 Engine Control Module : Abnormal Update Rate
1636-9 (Slave) Engine #2 Electronic Control Module : Abnormal Update Rate
1042-9 ITSM : Abnormal Update RateNote: If Cat ET displays "Duplicate Type on data link. Unable to Service", there may be a problem with the harness inside the terminal box. Check the continuity between the following terminals:
P3-29 and P3-60
P5-60 and P5-68Verify that the jumper wire is in good condition. Make repairs, as needed.Expected Result:All of the modules are displayed on the "ECM Selector" screen. There are no active diagnostic codes for the data link.Results:
OK - All of the modules are displayed on the "ECM Selector" screen. There are no active diagnostic codes for the data link. The problem seems to be resolved.Repair: If any of the above codes are logged and the engine is not running properly, refer to Troubleshooting, "Symptom Troubleshooting".If any of the above codes are logged and the engine is running properly, there may be an intermittent problem in a connector or a wiring harness. Refer to Troubleshooting, "Electrical Connectors - Inspect".STOP
Not OK - At least one of the modules is not displayed on the "ECM Selector" screen. There may be an active diagnostic code for the data link. Proceed to Test Step 3.Test Step 3. CHECK THE WIRING FOR THE DATA LINK
Remove the electrical power from the engine.
Disconnect Cat ET from the service tool connector.
Disconnect the following connectors:
P1 connector from the master ECM
P3 connector from the slave ECM
P5 connector from the ASM
Customer connector P6
14-pin connector from the ITSM
Measure the resistance between the points that are listed in Table 1. During each measurement, wiggle the wires in the harness in order to check for an intermittent problem. Be sure to wiggle the wires near each of the connectors.
Table 1
Resistance Measurements for the Data Link
Connector and Terminal Connector and Terminal
P1-8 P3-8
Service tool connector
Terminal D
P5-8
P6-7
Terminal J of the 14-pin connector on the ITSM
P3-8 Service tool connector
Terminal D
P1-9 P3-9
P5-9
Service tool connector
Terminal E
J6-17
Terminal N of the 14-pin connector on the ITSM
P3-9 Service tool connector
Terminal E
P1-8 Ground strap for the master ECM
P1-9 Ground strap for the master ECM Expected Result:Each check of the resistance between the connectors is less than 5 Ohms.Each check of the resistance between the connector and the ground strap is greater than 20,000 Ohms.Results:
OK - Each check of the resistance for the data link is within the specification. The wiring for the data link ap