C13, C15, and C18 Engines Troubleshooting – ECM – Replace

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 in order 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”.


If the flash file and engine application are not matched, engine damage may result.

Perform the following procedure in order to replace the ECM:


  1. Record the configuration data: 
    1. Try to establish communication between the Caterpillar Electronic Technician (ET) and the ECM. Proceed to Test Step 2 if Cat ET does not communicate with the ECM.


    1. Print the parameters from the “Configuration” screen on Cat ET. If a printer is unavailable, record all of the parameters.


    1. Obtain the customer passwords from the vehicle owner. 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.


    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 data from the suspect ECM.Note: If the “Copy Configuration” process fails and the parameters are not obtained in Step 5.a, the parameters must be obtained elsewhere. Some of the system configuration parameters are stamped on the engine information plate. The aftertreatment identification information is stamped on the CEM identification 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).


  1. Remove the ECM: 
    1. Turn the keyswitch OFF.


    1. Disconnect the P1 and P2 connectors.


    1. Disconnect the ECM ground strap.


    1. Remove the mounting hardware at each corner of the ECM.


  1. Install the replacement ECM: 
    1. Use the old mounting hardware to install the replacement ECM.


    1. Connect the ECM ground strap.


    1. Connect the P1 and P2 connectors. Refer to Troubleshooting, “Electrical Connectors – Inspect” for the correct torque values.


  1. Configure the replacement ECM: 
    1. Flash program the latest available flash file into the ECM. Refer to Troubleshooting, “ECM Software – Install” for the correct procedure.


    1. Use Cat ET to match the engine application and the interlock code if the replacement ECM was used for a different application.Note: Two sets of factory passwords are required in order to program the Aftertreatment parameters.


    1. If the “Copy Configuration” process from Step 1 was successful, return to the “Copy Configuration/ECM Replacement” screen on Cat ET and select “Program ECM”. Proceed to Step 4.e when programming is complete.


    1. If the “Copy Configuration” process from Step 1 was unsuccessful, manually program the ECM parameters. The parameters must match the parameters from Step 1.


    1. Program the engine monitoring system, if necessary.


    1. Calibrate the engine speed/timing if there is a diagnostic code for speed/timing sensor calibration. The procedure is in Troubleshooting, “Timing – Calibrate”.Note: If an engine is a Series C7.1 or Series C9.3, use Cat ET to perform the “fuel system functional test”. This test established a baseline value of the fuel system rate of fuel return at high rail pressure. Other diagnostic codes may be activated if this test is not performed.


  1. Determine the most recent cleaning of the Diesel Particulate Filter (DPF): 
    1. If the DPF was cleaned within the last 500 hours, return the engine to service.


    1. If the DPF was not cleaned within 500 hours, clean the DPF. Refer to Special Instruction, REHS5045, “Diesel Particulate Filter (DPF) Maintenance on Tier 4 Products Equipped with a Diesel Particulate Filter (DPF)”. Refer to Systems Operation and Testing and Adjusting, “Diesel Particulate Filter – Clean” for the correct procedure.

Note: After an ash service regeneration, there will be a delay in soot accumulation shown on the gauge.

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