BOLT 0S1618 - Caterpillar

System Operation Description:The CAN data link is used to communicate information between the Electronic Control Module (ECM) and other modules. Use this procedure to troubleshoot any suspect problems with the CAN data link.This procedure identifies the following problems:
Faulty connectors
Missing termination resistors
Short circuits
Open circuits
Faulty marine power displayA problem with the CAN data link is probably caused by a short circuit to ground or a short circuit to another voltage source in the harness. The next likely cause is a problem with a module that is connected to the data link. The least likely cause is a problem with the ECM.
Illustration 1 g01136702
Schematic for the CAN data linkTest Step 1. Inspect the Electrical Connectors and the Wiring
Turn the keyswitch to the OFF position.
Illustration 2 g01130302
Engine components for the CAN data link (1) J1/P1 connectors (2) Termination resistor (3) J60 connector for the electronic service tool (4) J61 customer connector
Thoroughly inspect connectors (1). Inspect all of the connectors that are associated with the CAN data link. Refer to Troubleshooting, "Electrical Connectors - Inspect" for details.
Illustration 3 g01091318
P1 terminals that are associated with the CAN data link (P1-34) CAN data link − (P1-42) CAN shield (P1-50) 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 for the proper torque. Refer to Troubleshooting, "Electrical Connectors - Inspect" for the correct torque values.
Check the allen head screw 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 okay. 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
Turn the keyswitch to the OFF position.
Disconnect the Marine Power Display (MPD).
Disconnect the Caterpillar Electronic Technician (Cat ET) from the service tool connector.
Disconnect the P1 connector.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. A termination resistor is missing.Repair: Verify that two termination resistors are connected to the data link. One resistor must be located 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