0432248 JOHNSON NEEDLE, Bearing

Illustration 1 g01390328
Schematic for the CAN data link for the J1 ECM connector
Illustration 2 g01390398
Schematic for the CAN data link for the J2 ECM connector
Table 1
Troubleshooting Test Steps Values Results
1. Inspect the Electrical Connectors and the Wiring
A. Remove the electrical power from the ECM.
B. Thoroughly inspect connectors (1), (2), and (3). Inspect all the connectors that are associated with the CAN data link. Refer to Troubleshooting, "Electrical Connectors - Inspect", for details.
C. Perform a 45 N (10 lb) pull test on each of the wires that are associated with the CAN data link.
D. 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.
E. Check the wiring harnesses for abrasion, for corrosion and for pinch points.
Connectors, Pins, and Sockets
Result: The harness and wiring appear to be OK.
Proceed to Test Step 2.
Result: There is a problem in the wiring harness.
Repair: Repair the connectors and/or the wiring. Replace parts, if necessary. Ensure that all the seals are properly in place and ensure that the connectors are completely coupled. Verify that the problem is resolved.
STOP
2. Verify the Proper Installation of the Termination Resistors
A. Remove the electrical power from the ECM.
B. Disconnect the display panel from the data link.
C. Disconnect the Cat® Electronic Technician (ET) from the service tool connector.
D. Disconnect the P1 ECM connector.
Note: Wiggle the harness during the following measurements in order to reveal an intermittent condition.
(E.) Measure the resistance between terminals P1-50 (CAN Data Link +) and P1-34 (CAN Data Link -).
The resistance is between 57 and 63 Ohms.
Result: The resistance is between 57 and 63 Ohms.
Proceed to Test Step 3.
Result: The resistance is between 114 Ohms and 126 Ohms. A termination resistor is missing.
Verify that two termination resistors are connected to the data link. One resistor must be on each end of the data link. The engine is shipped with one termination resistor that is installed between the ECM and the customer connector. Refer to the appropriate electrical schematic to determine the missing resistor. Replace the missing resistor. Verify that the problem is resolved.
Result: The resistance is less than 57 Ohms. There may be a short circuit in the harness. Proceed to Test Step 3.
Result: The resistance is greater than 126 Ohms. There may be an open circuit in the harness. Proceed to Test Step 4.
Table 2
Resistance Measurements for the CAN Data Link
Connector and Terminal Terminal
P1-50 (CAN data link +) All the other terminals on the P1 connector
Engine ground
P1-34 (CAN data link -) All the other terminals on the P1 connector
Engine ground
Table 3
Troubleshooting Test Steps Values Results
3. Check the Harness for a Short Circuit
A. Remove both termination resistors from the CAN data link.
B. Disconnect the display panel.
C. Measure the resistance between the points that are listed in the table. Be sure to wiggle the wires in the harnesses as you make each resistance measurement.
Resistance
Result: Each check of the resistance indicates an open circuit. The harness is not shorted.
Proceed to Test Step 4.
Result: At least one check of the resistance does not indicate an open circuit.
There is a short circuit in a harness. There may be a problem with a connector. Repair the wiring and/or the connector. Replace part, if necessary. Verify that the problem is resolved.
STOP
4. Check the Harness for an Open Circuit
A. Remove both termination resistors from the CAN data link.
B. Fabricate a jumper wire that is long enough to create a test circuit across the connector for the termination resistor. Crimp connector sockets to each end of the jumper wire.
C. Use the jumper wire to create a short circuit between terminals A and B on the tees connector for the termination resistor that is located between the P1 ECM connector and the customer connector. This will effectively replace the termination resistor with a short circuit.
D. Measure the resistance between terminals P1-50 (CAN data link +) and P1-34 (CAN data link -).
E. Remove the jumper wire.
F. Use the jumper wire to create a short circuit between terminals A and B on the tees connector for the termination resistor that is on the customers harness after the Customer Connector. This will effectively replace the termination resistor with a short circuit.
G. Measure the resistance between terminals P1-50 (CAN data link +) and P1-34 (CAN data link -).
H. Measure the resistance between terminals P1-50 (CAN data link +) and P1-34 (CAN data link -).
I. Connect the J1/P1 connectors.
Resistance
Result: A short circuit exists while the jumper wire is in place. There is not an open circuit.
Proceed to Test Step 5.
Result: A short circuit does not exist while the jumper wire is in place. There is an open circuit or excessive resistance in the circuit. There may be a problem in a connector.
Repair the wiring and/or the connector. Replace parts, if necessary. Verify that the problem is resolved.
STOP
5. Check the Display Panel
A. Connect the display panel to another engine.
B. Operate the engine and monitor the display panel.
Display Panel
Result: The display panel operates properly on another engine.
Connect the display panel to the original engine. If the display panel operates correctly, there may be a problem with an electrical connector. Refer to Troubleshooting, "Electrical Connectors - Inspect", If the display panel does not operate correctly on the original engine, there may be a problem with the ECM. It is unlikely that the ECM has failed. Perform this entire procedure again. If the display panel does not operate correctly, replace the ECM.
STOP
Result: The display panel does not operate properly on another engine.
Replace the display panel. Verify that the problem is resolved.
STOP