System Operation Description:
If any of the following conditions have occurred, calibrate the injector trim codes:
- Replacement of the Electronic Control Module (ECM)
- Replacement of any of the unit injectors
A special code is stamped on the top of each unit injector. The injector trim code allows the ECM to compensate for variances in manufacturing.
Note: Changing the injector trim codes will not increase the power that is available to the engine.
Test Step 1. Record Injector Trim Codes
- Use Table 1 to record the injector trim code and the corresponding cylinder number for each unit injector that will be replaced.
Table 1 Injector Trim Code Cylinder Old New 1 2 3 4 5 6 Note: If the ECM is replaced, all injector trim codes must be recorded. The injector trim codes can be found in “Calibrations” under the “Service” menu on the Caterpillar Electronic Technician (ET).
Expected Result:
All injector trim codes were obtained.
Results:
- OK – All injector trim codes were obtained. Proceed to Test Step 2.
- Not OK – The injector trim codes were not obtained.
Repair: Remove the valve cover and record the injector trim code and the corresponding cylinder number for each unit injector.
Proceed to Test Step 2.
Test Step 2. Replace Hardware
- Replace the suspect unit injectors and/or the ECM.
- Record the injector trim code and the corresponding cylinder number for each unit injector.
Expected Result:
All hardware was successfully replaced and the new injector trim codes were recorded.
Results:
- OK – The hardware was successfully replaced. Proceed to Test Step 3.
Test Step 3. Enter Injector Trim Codes into the ECM
- Connect Cat ET to the service tool connector.
- Turn the keyswitch to the ON position.
- Open the “Injector Codes Calibration” in “Calibrations” under the “Service” menu on Cat ET.
- Enter the new injector trim code for each cylinder.
Results:
- OK – STOP