INSPECTION PROCEDURE 2: Does not Move Forward: 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 item 2: Underdrive Solenoid Valve.
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.
  - Item 2: Underdrive Solenoid Valve.
    - An audible clicking or buzzing should be heard when the underdrive solenoid valve is energized.
4. Turn the ignition switch to the "LOCK" (OFF) position.
  Q: Is the solenoid valve operating properly?
  1. YES: Go to Step 2.
  2. NO: Replace the torque converter. Refer to TRANSAXLE <4A/T> or Refer to TRANSAXLE <5A/T>.
    
    Fig 1: Connecting Special Tool MB991910 To Data Link Connector
    Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
STEP 2. Check the hydraulic pressure.
Shift the selector lever to the sport mode then measure the hydraulic pressure of each element in 1st speed to check and see if each respective hydraulic pressure is within the range of standard pressure. Refer to , HYDRAULIC PRESSURE TEST .

Q: Is the hydraulic pressure within the standard value?
1. YES: Go to Step 3.
2. NO: Go to Step 4.
STEP 3. Check the underdrive clutch system.
1. Remove the valve body cover and valve body. Refer to TRANSAXLE <4A/T> or Refer to TRANSAXLE <5A/T>.
2. Blow 108 kPa (15 psi) compressed air into the underdrive clutch oil orifice of the transaxle case, and check if the underdrive clutch piston moves and air pressure is maintained in that condition.
  Q: Is the air pressure maintained?
  1. YES: Go to Step 4.
  2. NO: Go to Step 6.
    
    Fig 2: Locating Underdrive Clutch Oil Orifice
    Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
STEP 4. Disassemble and clean the valve body.
Check the O-ring installation bolts for looseness and valve body for damage. Repair or replace the faulty parts. Refer to VALVE BODY <4A/T> or Refer to VALVE BODY <5A/T>.

Replace the valve body assembly if the damage is too extensive. Then check the symptom.

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