INSPECTION PROCEDURE 9: Shift Shock and Slipping: Diagnosis

WARNING: This page is about a different variant/trim than selected.

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

STEP 1. Using scan tool MB991958, check actuator test.
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. Set scan tool MB991958 to the actuator test mode for following items.
  1. Item 1: Low-reverse solenoid valve
  2. Item 2: Underdrive solenoid valve
  3. Item 3: Second solenoid valve
  4. Item 4: Overdrive solenoid valve
  5. Item 5: Reduction solenoid valve <5A/T>
    - An audible clicking or buzzing should be heard when the solenoid valves are energized.
4. Turn the ignition switch to the "LOCK" (OFF) position.
  
  Fig 1: Connecting Special Tool MB991910 To Data Link Connector
  Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
  
  Q: Are the solenoid valves operating properly?
  1. YES: Go to Step 2.
  2. NO: Repair or replace the solenoid valves. Refer to VALVE BODY <4A/T> or VALVE BODY <5A/T>. Then confirm that the symptom is eliminated.
STEP 2. Check the hydraulic pressure.
1. Measure the hydraulic pressure of each element. Check if each hydraulic pressure is within the standard value. Refer to , HYDRAULIC PRESSURE TEST .
2. If some elements pressure are within the standard value and some are not, recheck the symptom.
  Q: Are all hydraulic pressures within the standard value?
  1. YES: Go to Step 6.
  2. NO: Go to Step 3.
STEP 3. Adjust the line pressure.
Adjust the line pressure. Refer to , LINE PRESSURE ADJUSTMENT . Then check the symptom.

Q: Is the symptom eliminated?
1. YES: The procedure is complete.
2. NO: Go to Step 4.
STEP 4. 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 5.
  
  Fig 2: Identifying Valve Body Assembly
  Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
STEP 5. Check the oil pump.
1. Remove the transaxle.
2. Check the oil pump (incorrect installation, damage and etc.) and replace the oil pump assembly if necessary (The oil pump cannot be disassembly). Refer to TRANSAXLE <4A/T> or TRANSAXLE <5A/T>. Confirm that the malfunction symptom is eliminated.
  Q: Is the symptom eliminated?
  1. YES: The procedure is complete.
  2. NO: Go to Step 7.
    
    Fig 3: Locating Oil Pump
    Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
STEP 6. Check each brake and clutch.
1. Remove the transaxle.
2. Check the facing for seizure and piston seal ring for damage and interference with retainer. Repair or replace the faulty parts. Refer to TRANSAXLE , UNDERDRIVE CLUTCH AND INPUT SHAFT , REVERSE AND OVERDRIVE CLUTCH <4A/T> or TRANSAXLE , UNDERDRIVE CLUTCH AND INPUT SHAFT , REVERSE AND OVERDRIVE CLUTCH <5A/T>. Then Retest the system.
  
  Fig 4: Identifying Automatic Transmission Components - 4A/T
  Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
  
  Q: Is the symptom eliminated?
  1. YES: The procedure is complete.
  2. NO: Go to Step 7.
    
    Fig 5: Identifying Automatic Transmission Components - 5A/T
    Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
STEP 7. 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.