Inspection Procedure 12

INSPECTION PROCEDURE 12: The gear shifting does not occur. (The transaxle does not upshift or downshift.)

CAUTION:
Whenever the ECU is replaced, ensure that the CAN bus lines are normal.

COMMENTS ON TROUBLE SYMPTOM

The CAN bus lines, mechatronic assembly, clutch assembly, or transaxle assembly may have a problem.

PROBABLE CAUSES

- Malfunction of the CAN bus lines
- Malfunction of the mechatronic assembly
- Malfunction of the clutch assembly
- Malfunction of the transaxle assembly

DIAGNOSTIC PROCEDURE

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

STEP 1. Scan tool CAN bus diagnostics

Using scan tool MB991958, diagnose the CAN bus lines.

Q. Is the check result normal?

YES Go to Step 2.
NO Repair the CAN bus lines. CAN Bus Diagnostics Chart.) After repairing the CAN bus line, go to Step 2.
STEP 2. Retest the system.

Q. Does a malfunction take place again?

YES Replace the transaxle assembly. (Refer to Removal and Replacement.)
NO Intermittent malfunction. How to Cope With Intermittent Malfunctions.)