GASKET-COOLER COVER 9N3354 - Caterpillar

System Operation Description:Use this procedure to troubleshoot any suspect problems with the CAN Data Link.This procedure covers the following diagnostic code:
247-09 J1939 Data Link communicationsThe test steps that are described in this test can help solve the following problems.
Faulty connectors
Terminating resistors
Short circuits
Open circuits
Faulty module
Faulty Electronic Control Module (ECM)
Illustration 1 g01058327
Typical schematic
Illustration 2 g01091318
P1 ECM connector
(P1-34) J1939 data link −
(P1-42) J1939 shield
(P1-50) J1939 data link + Test Step 1. Inspect Electrical Connectors and Wiring
Turn the engine control switch (ECS) to the OFF/RESET position.
Thoroughly inspect the J1/P1 ECM connector and the J2/P2 ECM connector. Inspect all of the connectors that are associated with the circuit. Refer to Troubleshooting, "Electrical Connectors - Inspect" for details.
Perform a 45 N (10 lb) pull test on each of the wires in the ECM connectors that are associated with the circuit.
Check the ECM connector (allen head screw) for the proper torque of 6.0 N m (55 lb in).
Check the harness and 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 or of pinch points.Results:
OK - The harness and wiring appear to be okay. Proceed to Test Step 2.
Not OK - There is a problem in the wiring harness.Repair: Perform the following 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. Refer to Troubleshooting, "Electrical Connectors - Inspect".Verify that the repair eliminates the problem.STOPTest Step 2. Verify the Proper Installation of the Data Link Circuit
Disconnect any module that is connected to the CAN Data Link.
Disconnect J1/P1 ECM connector and measure the resistance between 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 within the range. Proceed to Test Step 5.
Not OK - The range of the resistance is 114 Ohms to 126 Ohms. A terminating resistor is missing.Repair: Verify that two terminating resistors exist on the data link. One resistor must be located on each end of the data link. The engine is shipped with one terminating resistor that is installed between the ECM and the customer connector.Refer to the Electrical Schematic in order to determine the missing resistor.Verify that the repair eliminates the problem.STOP
Not OK - Resistance is less than 57 Ohms. Proceed to Test Step 3.
Not OK - Resistance is greater than 126 Ohms. Proceed to Test Step 4.Test Step 3. Check for a Short Circuit
Disconnect the J1/P1 ECM connector.
Remove the terminating resistors from the CAN Data Link.
If a J1939 display is installed, disconnect the display.
Measure the resistance from the following pins to every pin on ECM connector P1 and to engine ground.
P1-50 (CAN Data Link +)
P1-34 (CAN Data Link -)
P1-42 (CAN Data Link Shield)Expected Result:The resistance is greater than 20,000 Ohms.Results:
OK - There are no shorts. Proceed to Test Step 4.
Not OK - A short exists in the wiring harness.Repair: Make