How to Diagnose the CAN Bus Line

The contents in this article reflect the changes called out by TSB 04-23-002.







HOW TO DIAGNOSE THE CAN BUS LINE

Required Special Tools:
- MB991958: Scan Tool (MUT-III Sub Assembly)
- MB991824: Vehicle Communication Interface (V.C.I.)
- MB991827: MUT-III USB Cable
- MB991910: MUT-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. Connect scan tool MB991958 to the data link connector.
2. Turn the ignition switch to the "ON" position.
3. Select "CAN bus diagnosis" from the start-up screen.
4. When the vehicle information is displayed, confirm that it matches the vehicle whose CAN bus lines will be diagnosed.
- If they matches, go to step 8.
- If not, go to step 5.

5. Select the "view vehicle information" button.
6. Enter the vehicle information and select the "OK" button.
7. When the vehicle information is displayed, confirm again that it matches the vehicle whose CAN bus lines will be diagnosed.
- If they matches, go to step 8.
- If not, go to step 5.

8. Select the "OK" button.
9. When the optional equipment screen is displayed, choose the one which the vehicle is fitted with, and then select the "OK" button.




HOW TO RESET (INITIALIZE) A/T LEARNED VALUE





A/T learned value must be reset whenever the automatic transmission, engine assembly, A/T valve body, or A/T solenoid valve is replaced. It cannot be reset by disconnecting the battery. Use the MUT-III/STV as follows:

1. Shift the selector lever to P and turn the ignition key to the LOCK (OFF) position.
2. Connect the MUT-III/STV to the vehicle's data link connector.
3. In the ELC-A/T menu screen, select "Special Function," then select "Memory Reset."
4. Select "OK" to reset the A/T learned value memory.

Note: Thie reset procedure will also atuomatically initialize the INECS-II Learned Value. A/T DTCs and A/T freeze-frame data will be erased. (Engine DTCs, engine-related freeze-frame data, and Readiness status will remain even after A/T Learned Value is reset.)