Inspection Procedure 12: The Gear Shifting Does Not Occur. (The Transaxle Does Not Upshift or Downshift.)

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. 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 mechatronic assembly. Then go to Step 3.
NO: Intermittent malfunction.

STEP 3. Retest the system.
Q: Does a malfunction take place again?
YES: Replace the clutch assembly. Then go to Step 4.
NO: Intermittent malfunction.

STEP 4. Retest the system.
Q: Does a malfunction take place again?
YES: Replace the transaxle assembly.
NO: Intermittent malfunction.