C15 and C18 Engines for Caterpillar Built Machines ECM - Replace 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. Use these procedures to ensure that the ECM is the cause of the problem.

Note: Ensure that the ECM is receiving power and that the ECM is properly wired to the negative battery circuit before you attempt to replace the ECM. Refer to the diagnostic functional test Troubleshooting, "Electrical Power Supply Circuit - Test".

Some application software supports the use of a new ECM as a test ECM. A new ECM can be temporarily placed into a "Test ECM Mode". This ECM can then be used to replace a suspect ECM in order to determine if the suspect ECM is faulty. Refer to programming parameters Troubleshooting, "Test ECM Mode".

Perform the following procedure in order to replace the ECM:

1. Use the "Copy Configuration/ECM Replacement" feature that is found under the "Service" menu on Cat ET. Select "Load from ECM" in order to copy the configuration from the suspect ECM.

   Note: If the "Copy Configuration" process fails and the parameters were not obtained, the parameters must be obtained elsewhere. Some parameters are stamped on the engine information plate, but most parameters must be obtained from the factory.

1. Remove the ECM from the engine.

   1. Remove the electrical power from the ECM.

   2. Disconnect the J1/P1 and J2/P2 ECM connectors.
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      NOTICE
      Use a suitable container to catch any fuel that might spill. Clean up any spilled fuel immediately.

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      NOTICE
      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.

   3. Remove the fuel lines (if equipped) from the ECM.

   4. Remove the mounting bolts from the ECM.

   5. Disconnect the ECM ground strap from the engine.

2. Install the replacement ECM.

   1. If the old mounting hardware is in good repair, you can use the old mounting hardware to install the replacement ECM.

   2. Reconnect the fuel lines (if equipped).

   3. Ensure that the ECM mounting hardware is installed correctly. The fuel lines must not put tension on the ECM. 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 ECM cannot be moved slightly in the grommets, check that the fuel lines (if equipped) are not pulling the ECM against one side of the grommets.

   4. Connect the ECM ground strap.

   5. Connect the J1/P1 and J2/P2 ECM connectors. Tighten the allen head screw on each of the ECM connectors to the proper torque. Refer to the diagnostic functional test Troubleshooting, "Electrical Connectors - Inspect" for the correct torque value.

3. Program the flash file into the ECM. Refer to programming parameters Troubleshooting, "Flash Programming".

4. If the replacement ECM was used previously for a different application, use Cat ET to match the engine application and the flash file.

5. Configure the ECM.

   1. If the "Load from ECM" process was successful, return to the "Copy Configuration/ECM Replacement" screen on Cat ET and select "Program ECM".

      After using the "Program ECM" feature, be sure to cycle the power to the ECM. Wait at least 15 seconds after turning the keyswitch to the OFF position.

      Note: Some control modules have a power off delay. The 15 seconds will be sufficient to cover this delay.

   2. If the "Program ECM" process was successful, proceed to Step 7.

   3. If the "Program ECM" process was unsuccessful, manually program the ECM parameters into the replacement ECM. The parameters must match the parameters from Step 1.

      Note: If the "Copy Configuration" process fails and the parameters were not obtained , the parameters must be obtained elsewhere. Some parameters are stamped on the engine information plate, but most parameters must be obtained from the factory.

   4. If necessary, program the engine monitoring system.

6. Program the injector trim files. Refer to programming parameters Troubleshooting, "Injector Trim File".

7. Check for an active diagnostic code for timing calibration.

   If the diagnostic code is active, calibrate the injection timing. Refer to calibration procedures Troubleshooting, "Engine Speed/Timing Sensor - Calibrate".

8. Check for diagnostic codes and for event codes.