FREE REPAIR MANUALS & LABOR GUIDES 1982-2013 Vehicles
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Control Module: Testing and Inspection

LEARNED VALUE READ & SAVE AND WRITE LEARNED VALUE (CHANGED ECU)

Required Special Tools:
^ MB991958: Scan Tool (M.U.T.-III Sub Assembly)
^ MB991824: V.C.I.
^ MB991827: M.U.T.-III USB Cable
^ MB991910: M.U.T.-III Main Harness A

CAUTION:
To prevent damage to scan tool MB991958, always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool MB991958.






1. After the ignition switch is in "LOCK" (OFF) position, connect scan tool MB991958 to the data link connector.
2. Turn the ignition switch to the "ON" position.
3. Select "MFI" from System select Screen of scan tool MB991958.
4. Select "Special Function" from MFI Screen.
5. Select "Timing chain maintenance" from Special Function Screen.
6. Select "Learned value Read & Save" from Timing chain maintenance Screen.
7. Press "OK" to store the initial learning value file.

NOTE: When the initial learning value file is appropriately stored, "Learned value Save Complete" is shown on the screen of the scan tool MB991958.

NOTE: Calculating the amount of elongation of the timing chain by the ECM takes the time. Thus, the file cannot be stored for a while after the ECM initialization or replacement.

8. Replace the ECM.
9. Select "Write learned value (Changed ECU)" from Timing chain maintenance Screen.
10. Select the initial learning value file stored during Step 7 to write the initial learning value.

NOTE: Use only the initial learning value file stored during Step 7 without using any other files.

NOTE: When the initial learning value is appropriately written, "Learned value writing Completed." is shown on the screen of the scan tool MB991958.

LEARNED VALUE RESET

Required Special Tools:
^ MB991958: Scan Tool (M.U.T.-III Sub Assembly)
^ MB991824: V.C.I.
^ MB991827: M.U.T.-III USB Cable
^ MB991910: M.U.T.-III Main Harness A

CAUTION:
To prevent damage to scan tool MB991958, always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool MB991958.






1. After the ignition switch is in "LOCK" (OFF) position, connect scan tool MB991958 to the data link connector.
2. Turn the ignition switch to the "ON" position.
3. Select "MFI" from System select Screen of scan tool MB991958.
4. Select "Special Function" from MFI Screen.
5. Select "Timing chain maintenance" from Special Function Screen.
6. Select "Learned value reset" from Timing chain maintenance Screen.
7. Press "OK" to reset the initial learning value.

TEST/LIMIT VALUE READOUT

Required Special Tools:
^ MB991958: Scan Tool (M.U.T.-III Sub Assembly)
^ MB991824: V.C.I.
^ MB991827: M.U.T.-III USB Cable
^ MB991910: M.U.T.-III Main Harness A

CAUTION:
To prevent damage to scan tool MB991958, always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool MB991958.






1. After the ignition switch is in "LOCK" (OFF) position, connect scan tool MB991958 to the data link connector.
2. Turn the ignition switch to the "ON" position.
3. Select "MFI" from System select Screen of scan tool MB991958.
4. Select "Special Function" from MFI Screen.
5. Select "Timing chain maintenance" from Special Function Screen.
6. Select "Test/Limit value readout" from Timing chain maintenance Screen.
7. Read the value of percentage (%) shown on the screen.

NOTE: The value of percentage (%) shown on the screen is the amount of elongation of the timing chain calculated by the ECM based on the initial learning value, and thus is not the actual amount. Use this for the reference only.