NUT 8T1757 - Caterpillar

The Engine Control Module (ECM) contains no moving parts. Replacement of the ECM can be costly. Replacement can also be a time consuming task. Follow the troubleshooting procedures in this manual to ensure that replacing the ECM will correct the problem. Verify that the suspect ECM is the cause of the problem.A test ECM can be used to determine if the ECM is faulty. Refer to Troubleshooting, "Test ECM Mode".Note: Do not interchange the primary ECM with the secondary ECM to determine if an ECM is faulty. If replacement of both modules is necessary, replace the modules one at a time. Failure to program each ECM correctly may result in improper engine operation.
If the flash file and engine application are not matched, engine damage may result.
Perform the following procedure to replace the ECM:
Record the configuration data:
Try to establish communication between the Cat® Electronic Technician (ET) and the ECM. Proceed to Test Step 2 if Cat ET does not communicate with the ECM.
Print the parameters from the "Configuration" screen on Cat ET. If a printer is unavailable, record all the parameters.
Obtain the customer passwords. Access the customer specified parameters with Cat ET. Record the value of each customer parameter.
Record ECM lifetime totals.________
Record any logged diagnostic codes. ________Note: If the customer passwords are not available, proceed to Troubleshooting, "Customer Passwords" for details that are related to customer passwords.
Use the "Copy Configuration/ECM Replacement" feature that is found under the "Service" menu on Cat ET. Select "Load from ECM" to copy the configuration data from the suspect ECM.Note: If the "Copy Configuration" process fails and the parameters are not obtained in Step 4.f, the parameters must be obtained elsewhere. Some of the system configuration parameters are stamped on the engine information plate. Most of the parameters must be obtained from the factory. Parameters that are related to customer specified parameters must be obtained from the customer or from the Original Equipment Manufacturer (OEM).
Remove the ECM:
Remove the electrical power from the ECM.
Disconnect the P1 and P2 connectors.
Use a suitable container to catch any fuel that might spill. Clean up any spilled fuel immediately.
Do not allow dirt to enter the fuel system. Thoroughly clean the area around a fuel system component that will be disconnected. Fit a suitable cover over disconnected fuel system component.
Remove the fuel lines (if equipped) from the ECM.
Disconnect the ECM ground strap.
Remove the mounting hardware at each corner of the ECM.
Install the replacement ECM:
Use the old mounting hardware to install the replacement ECM.
Reconnect the fuel lines (if equipped).Note: Ensure that the ECM mounting hardware is installed correctly. The rubber grommets are used to protect the ECM from excessive vibration. The ECM must be able to drift in the rubber grommets. If the installation is equipped with fuel lines, the fuel lines must not put tension on the ECM.
Connect the ECM ground strap.
Connect the P1 and P2 connectors. Refer to Troubleshooting, "Electrical Connectors - Inspect" for the correct torque values.
Configure the replacement ECM:
Flash program the latest available flash file into the