BUCKET GP-GENERAL PURPOSE 3948476 - Caterpillar

Probable Causes
Electrical power supply
Electrical connectors
Communication adapter and/or cables
Electronic service tool
A problem with the harness code for the slave ECMRecommended Repairs
Electrical Power Supply
Check power to the module. Refer to Troubleshooting, "Electrical Power Supply".Note: If a module is not receiving power, the module will not communicate.Electrical Connectors
Check the following components:
Power supply connections and ground to the module
Wiring harnesses and the connectors for the moduleRefer to Troubleshooting, "Inspecting Electrical Connectors".Communication Adapter and/or Cables
Check the condition of the fuse for the communication adapter.
Disconnect the communication adapter and the cables from the service tool connector. Then reconnect the communication adapter.If you are using the 171-4401 Communication Adapter II, refer to Manual, "Communication Adapter II User's Manual".
Verify that power supply voltage is present between terminals A and B of the J5 service tool connector. If the communication adapter is not receiving power, the display will be blank.Electronic Service Tool
In order to eliminate Caterpillar Electronic Technician (ET) as the problem, connect Cat ET to a different engine. If the same problem occurs with a different engine, check Cat ET and the related equipment in order to determine the cause of the problem.Check the Harness Code for the Slave ECM
The harness inside the terminal box has a jumper wire (harness code) that connects terminals J3-29 and J3-60. The ECM that is connected to the harness reads the harness code. This allows the ECM to operate as the slave ECM.If the jumper wire is disconnected, the slave ECM will assume the function of a master ECM. Cat ET will not communicate with any of the modules. Cat ET will display "Duplicate Type on data link. Unable to Service".Set the engine control to the OFF/RESET mode. Remove the electrical power from the engine. Check the continuity between terminals J3-29 and J3-60. Verify that the jumper wire is in good condition. Make repairs, as needed.