BOLT 1M8657 - Caterpillar

This procedure covers the following diagnostic code:
253-2 Personality Module : Erratic, Intermittent, or Incorrect
253-11 Personality Module : Other Failure ModeThe Electronic Control Module (ECM) contains no moving parts. Replacement of an ECM can be very costly. Before you replace an ECM, follow the troubleshooting procedures in this manual in order to ensure that replacement of the ECM will correct the problem.Note: Electronic control modules should not be interchanged in order to determine if an ECM is faulty. If electronic control modules are interchanged, all of the configuration data for each ECM must be transferred into Caterpillar Electronic Technician (ET). The configuration data must then be downloaded into the new ECM. Failure to program each ECM correctly may result in improper engine operation.Verify that the suspect ECM is the cause of the problem. Install the test ECM in place of the suspect ECM. Use Cat ET to transfer the software from the suspect ECM to the test ECM. Ensure that all of the parameters for the test ECM match the parameters of the suspect ECM. All of the parameters for the test ECM must match the parameters from the suspect ECM. Refer to the following test steps for details that relate to programming the ECM:If the test ECM resolves the problem, reconnect the suspect ECM. Verify that the problem recurs. If the problem recurs, permanently replace the suspect ECM with the test ECM.Note: If the parameters cannot be read from the suspect ECM, the parameters must be obtained from records or from the factory.Perform the following procedure to replace the ECM.
Use the "Service/Copy Configuration/ECM Replacement" function of Cat ET. Save the file. Select the "Load from ECM" function from the drop-down menu in Cat ET. You may also select the "Print" function in order to obtain a paper copy of the parameter settings.Note: Before you replace an ECM, record all of the logged events.
Connect the communications adapter and the personal computer to the suspect ECM. Establish communications with the ECM. Select "Service/Copy Configuration/ECM Replacement" from the drop-down menu on Cat ET. Cat ET will load the configuration parameters and the monitoring system parameters of the suspect ECM.
Select "Load from ECM" in the lower left corner of the Cat ET screen. Select the suspect ECM and select "OK". After the loading is complete, the Cat ET will display this message: "The data has been successfully loaded from the ECM". Select "OK".
Select "File/Disconnect F8" from the drop-down menu. Note: Do not shut down Cat ET.
Replace the ECM. Note: This procedure describes replacement of the engine ECM. Replacement of other electronic control modules is similar.
Set the engine control to the OFF/RESET mode.
Remove the electrical power from the engine.
Illustration 1 g01760398
Mounting of a typical A3 ECM
(1) ECM mounting hardware
(2) Ground strap assembly
(3) ECM connectors
Use a 4 mm allen wrench to disconnect ECM connectors (3).
Remove the mounting nuts from the studs that are part of ECM mounting hardware (1).
Remove the screw from the ECM for ground strap assembly (2). Note: The rubber grommets behind the