INSPECTION PROCEDURE 3: Does not Move Backward: 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 1: Low-Reverse 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 1: Low-Reverse Solenoid Valve.
    - An audible clicking or buzzing should be heard when the low-reverse 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: Repair or replace the low-reverse solenoid valve. Refer to VALVE BODY <4A/T> or Refer to VALVE BODY <5A/T>. Then confirm that the symptom is eliminated.
    
    Fig 1: Connecting Special Tool MB991910 To Data Link Connector
    Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
STEP 2. Check the hydraulic pressure (for reverse clutch).
Measure the hydraulic pressure for the reverse clutch when the selector lever is at the "R" range, and check if the hydraulic pressure is within the standard value. 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 5.
STEP 3. Check the hydraulic pressure (for low-reverse brake).
Measure the hydraulic pressure for the low-reverse brake when the selector lever is at the "R" range, and check if the hydraulic pressure is within the standard value. Refer to , HYDRAULIC PRESSURE TEST .

Q: Is the hydraulic pressure within the standard value?
1. YES: Go to Step 4.
2. NO: Go to Step 5.
STEP 4. Check the reverse clutch system and low-reverse brake 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 reverse clutch oil orifice of the transaxle case. Then check if the reverse clutch piston moves and air pressures are maintained in that condition. Repeat for the low-reverse brake.
  Q: Are the reverse clutch, low-reverse brake or both air pressures maintained?
  1. YES: Go to Step 5.
  2. NO: Go to Step 6.
    
    Fig 2: Locating Low-Reverse Brake Oil Orifice And Reverse Clutch Oil Orifice
    Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
STEP 5. 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 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 7.
  
  Fig 3: Identifying Valve Body Assembly
  Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
STEP 6. Check the reverse clutch, low-reverse brake or both. Remove the transaxle.
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 TRANSAXLE , REVERSE AND OVERDRIVE CLUTCH <4A/T> or Refer to TRANSAXLE , REVERSE AND OVERDRIVE CLUTCH <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 Reverse Clutch And Low-Reverse Brake
  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.