3126B Petroleum Engine Caterpillar

Electronic Service Tool Will Not Communicate with ECM

Usage:

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The connection of any electrical equipment and the disconnection of any electrical equipment may cause an explosion hazard which may result in injury or death. Do not connect any electrical equipment or disconnect any electrical equipment in an explosive atmosphere.

Probable Causes

Configuration for the communications adapter
Electrical connectors
Communication adapter and/or cables
Electrical power supply to the service tool connector
Caterpillar Electronic Technician (ET) and related hardware
Electrical power supply to the Electronic Control Module (ECM)
Personality module (flash file)
Cat data link

Recommended Actions

Start the engine. If the engine starts, but the ECM will not communicate with Cat ET, continue with this procedure. If the engine will not start, refer to the diagnostic procedure Troubleshooting, "Engine Cranks but Will Not Start". If the engine will not crank, refer to the diagnostic procedure Troubleshooting, "Engine Will Not Crank".

Configuration for the Communications Adapter

Access "Preferences" under the "Utilities" menu on Cat ET.

Verify that the correct "Communications Interface Device" is selected.

Verify that the correct "Port" is selected for use by the communication adapter.
Note: The most commonly used port is "COM 1".

Check for any hardware that is utilizing the same port as the communications adapter. If any devices are configured to use the same port, exit or close the software programs for that device.

Electrical Connectors

Check for correct installation of the J1/P1 and J2/P2 ECM connectors and of the service tool connector. Refer to the diagnostic functional test Troubleshooting, "Electrical Connectors - Inspect".

Communication Adapter and/or Cables

If you are using a Communication Adapter II, ensure that the firmware and driver files for the communication adapter are the most current files that are available. If the firmware and driver files do not match, the communication adapter will not communicate with Cat ET.

Disconnect the communication adapter and the cables from the service tool connector. Reconnect the communication adapter to the service tool connector.

Verify that the correct cable is being used between the communication adapter and the service tool connector. Refer to the diagnostic procedure Troubleshooting, "Electronic Service Tools".

Electrical Power Supply to the Service Tool Connector

Verify that battery voltage is present between terminals A and B of the service tool connector. If the communication adapter is not receiving power, the display on the communication adapter will be blank.

Cat ET and Related Hardware

In order to eliminate Cat ET and the related hardware as the problem, connect Cat ET to a different engine. If the same problem occurs on a different engine, check Cat ET and the related hardware in order to determine the cause of the problem.

Electrical Power Supply to the Electronic Control Module (ECM)

Check power to the ECM. Refer to the diagnostic functional test Troubleshooting, "Electrical Power Supply Circuit - Test".

Note: If the ECM is not receiving battery voltage, the ECM will not communicate.

Personality Module (Flash File)

Ensure that the correct personality module is properly installed in the ECM.

Note: The personality module that is provided in a new ECM is blank. The engine will not start and the engine will not communicate with Cat ET until the personality module has been flashed. Refer to the diagnostic procedure Troubleshooting, "Flash Programming".