770G and 772G Off-Highway Truck/Tractors Caterpillar

The Electronic Control Module (ECM) contains no moving parts. Replacement of the ECM can be costly. Replacement can also be a time consuming task. Most electronic failures occur in the wiring and connectors.

When troubleshooting has indicated that the ECM has failed, temporarily mount a new ECM to the side of the suspect ECM. Test the Machine with the new ECM. If the problem no longer exists, proceed with the following steps.

Replacement of the ECM

1. Record customer specified parameters from the failed ECM. Refer to Troubleshooting, "Electronic Service Tool Does Not Communicate" if the electronic service tool will not communicate.

   1. Obtain the customer passwords and record the customer passwords. Refer to Troubleshooting, "Customer Passwords" if the customer has lost the passwords.

   2. Use Cat Electronic Technician (ET) to access read customer specified parameters from the ECM.

   3. Record customer parameters on the "Customer Specified Parameters Worksheet".

2. Replace the faulty ECM.

3. Obtain the factory passwords.

   1. Record the machine hours from the hour meter.

   2. Use Cat ET to access the system configuration parameters. When the factory password screen appears, record the following information on the "factory passwords worksheet". ECM Serial Number, Engine Serial Number, Number Of the Service Tool and Total Tattletales

   3. Leave Cat ET on the factory password screen and obtain passwords by providing the information on the "factory passwords worksheet".

4. Program the new ECM.

   1. Enter the factory passwords at the factory password screen.

   2. All system configuration parameters must be programmed before exiting the factory password screen. The necessary system configuration parameters must be programmed before exiting this screen. If the parameters are not entered, new passwords are required.

      Note: If the customer specified parameters are entered before the system configuration parameters, the total tattletales will change. A new set of factory passwords will be necessary to access the system configuration parameters.

   3. Enter the original values in the "Read/Change Customer Specified Parameters". Obtain these values from the worksheet.