INSPECTION PROCEDURE 11: Early or Late Shifting in Some Gears: Diagnosis

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

1. STEP 1. Using scan tool MB991958, check special function: INVECS-II Cancel Command. 
   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. Start the engine.
   3. Set scan tool MB991958 to the actuator test mode.
      • Special function: INVECS-II Cancel Command.
        • Drive the vehicle and confirm the gear shifting correspond to the standard shift line of the shift pattern diagram. Refer to GENERAL DESCRIPTION  .
   4. Turn the ignition switch to the "LOCK" (OFF) position.

      Q: Does the gear shifting correspond to the standard shift line of the shift pattern diagram? 

      1. YES:  The symptom is due to characteristics of the INVECS-II system, but is not abnormal.
      2. NO:  Go to Step 2.
         Fig 1: Connecting Special Tool MB991910 To Data Link Connector

         Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
2. STEP 2. Check the shift points. 

   Q: Are the shift points early or late only when transmission fluid is 29°C (84°F) or less (early), or 125°C (257°F) or more (late)? 

   1. YES:  The symptom is due to characteristics of the INVECS-II system, but is not abnormal.
   2. NO:  Go to Step 3.
3. STEP 3. Disassemble and clean the valve body. 

   Check the O-ring installation bolts for looseness and the valve body for damage. Repair or replace the faulty parts. Refer to VALVE BODY <4A/T> or VALVE BODY <5A/T>.

   Replace the valve body assembly if the damages are thought to be irreparable. Then check the symptom.

   Q: Is the symptom eliminated? 

   1. YES:  The procedure is complete.
   2. NO:  Go to Step 4.
      Fig 2: Identifying Valve Body Assembly

      Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
4. STEP 4. Replace the PCM. 

   When the PCM is replaced, register the encrypted code. Refer to ENCRYPTED CODE REGISTRATION CRITERIA TABLE .

   Q: Is the symptom eliminated? 

   1. YES:  The procedure is complete.
   2. NO:  Start over at Step  1.