Inspection Procedure 1

INSPECTION PROCEDURE 1: Communication With Scan Tool Is Not Possible. (Middle Grade Type)

Part 1:

Part 2:

CIRCUIT OPERATION
The multi-center display unit (middle grade type) is linked to CAN communication lines to communicate with the combination meter and the powertrain control module, both of which have a terminator resistor.

TECHNICAL DESCRIPTION (COMMENT)
If the system does not communicate with the scan tool, power supply to the data link connector or CAN bus lines may be defective.

TROUBLESHOOTING HINTS
- The wiring harness or connectors may have loose, corroded, or damaged terminals, or terminals pushed back in the connector.

DIAGNOSIS

Required Special Tools:
- MB991958: Scan Tool (M.U.T.-III Sub Assembly)
- MB991824: Vehicle Communication Interface (V.C.I.)
- MB991827: M.U.T.-III USB Cable
- MB991910: M.U.T.-III Main Harness A (Vehicles with CAN communication system)

STEP 1. Check that the powertrain control module communicates with the scan tool.

Check if scan tool MB991958I can communicate with the multi-center display.







1. Connect scan tool MB991958 to the data link connector.
2. Turn the ignition switch to "ON" position.
3. Check if scan tool MB991958 can communicate with the powertrain control module.

Q: Is the check result satisfactory?

YES : Go to Step 2.

NO : Refer to MFI Diagnostic Trouble Code Chart Diagnostic Trouble Code Descriptions or MFI Diagnostic Trouble Code Chart. Diagnostic Trouble Code Descriptions

STEP 2. Using scan tool MB991958, diagnose the CAN bus line.

Use scan tool MB991958 to diagnose the CAN bus lines.

Q: Is the check result satisfactory?

YES : Diagnose the power supply circuit. Inspection Procedure 2

NO : Repair the CAN bus lines.