The personality module is incorrect for the engine, the engine family, or the engine application.
System Response:
The ECM will not log the diagnostic code. The diagnostic code may be viewed on a display module or on ET. Fuel injection is disabled for the engine. The engine will not start. The interlock can be reset using ET and factory passwords. This diagnostic code will always be active when a 799-12 "Need Service Tool update" is active.
Note: ET will not be able to reset the interlock if a personality module for a HEUI engine is installed in an ECM for a MEUI engine, or vice versa.
- Engine shutdown
Test Step 1. Check Diagnostic Codes
- Turn the keyswitch to the OFF/RESET position.
- Connect ET and check for any diagnostic codes.
Expected Result:
799-12 "Need Service Tool update" should not be active.
Results:
- OK - Proceed to Test Step 2.
- Not OK - Proceed to Test Step 3.
Test Step 2. Verify that the Correct ECM has been Installed
- Check the ECM part number.
- Check the last two characters of the ECM serial number.
Expected Result:
The last two characters of the ECM serial number should be "CD".
Results:
- OK - The correct ECM is installed.
Repair: Connect ET and verify that the correct personality module is installed. Replace the personality module, if necessary. Reprogram the interlock code.
Stop.
- Not OK - The ECM is incorrect.
Repair: Replace the ECM. Ensure that the serial number on the new ECM is correct for the engine. Refer to Troubleshooting, "Replacing the ECM" before replacing the ECM.
Stop.
Test Step 3. Perform the following test: CID 0799 FMI 12 Need Service Tool update
Results:
- OK - Stop.