CAMSHAFT-FUEL PUMP 1113771 - 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 display panelA 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.Note: The ECM and backup ECM have a dedicated CAN data link that is not shared by any other device. The ECM uses this data link in order to transmit the engine location to the backup ECM. The backup ECM will be programmed to this location. This Can data link is a circuit of the J2/P2 connector. Refer to figure 2.
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Schematic for the CAN data link for the J1 ECM connector
Illustration 2 g01390398
Schematic for the CAN data link for the J2 ECM connectorTest Step 1. Inspect the Electrical Connectors and the Wiring
Remove the electrical power from the ECM.
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Connector locations for the CAN data link (rear engine view) (1) P1 ECM connector (2) Customer Connector
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Connector locations for the CAN data link (top rear engine view) (2) Customer Connector (3) Termination resistor (4) Service tool connector
Thoroughly inspect connectors (1), (2), and (3). Inspect all of the connectors that are associated with the CAN data link. Refer to Troubleshooting, "Electrical Connectors - Inspect" for details.
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Terminal locations at the P1 ECM connector that are associated with the CAN data link (P1-34) CAN data link − (P1-42) CAN shield (P1-50) CAN data link +
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Terminal locations at the Customer Connector that are associated with the CAN data link (P1-16) CAN shield (P1-17) CAN data link + (P1-18) CAN data link −
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Terminal locations at the service tool connector that are associated with the CAN data link (Terminal C) CAN shield (Terminal G) CAN data link + (Terminal F) CAN data link −
Illustration 8 g01355248
Terminal locations at the connector for the termination resistor that are associated with the CAN data link (Terminal A) CAN data link + (Terminal B) CAN data link − (Terminal C) CAN shield
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.