INSPECTION PROCEDURE 13: Poor Acceleration: Diagnosis

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

STEP 1. Check the engine system.
Refer to POOR ACCELERATION for 4A/T .

Refer to POOR ACCELERATION for 5A/T .

Q: Is the inspection result good?
1. YES: Go to Step 2.
2. NO: Repair or replace the engine component(s).
STEP 2. Check each brake and clutch.
Perform the torque converter stall test. Refer to , TORQUE CONVERTER STALL TEST . Then retest the system.

Q: Is the symptom eliminated?
1. YES: The procedure is complete.
2. NO: Go to Step 3.
STEP 3. Perform the hydraulic pressure test.
Perform the hydraulic pressure test. Refer to , HYDRAULIC PRESSURE TEST . Then retest the system.

Q: Is the symptom eliminated?
1. YES: The procedure is complete.
2. NO: Go to Step 4.
STEP 4. Check each brake system and each clutch system.
1. Remove the valve body cover and valve body. Refer to TRANSAXLE <4A/T> or TRANSAXLE <5A/T>.
2. Blow 108 kPa (15 psi) compressed air into the each brake oil orifice and clutch oil orifice of the transaxle case, and check if each brake and each clutch piston move and air pressure is maintained.
  Q: Is the air pressure maintained?
  1. YES: The procedure is complete.
  2. NO: Go to Step 5.
    
    Fig 1: Identifying Reverse Clutch Oil Orifice And Direct Clutch Oil Orifice
    Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
STEP 5. Check each brake system and clutch system.
1. Remove the transaxle.
2. Check the facings 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> TRANSAXLE , UNDERDRIVE CLUTCH AND INPUT SHAFT , REVERSE AND OVERDRIVE CLUTCH <5A/T>. Then retest the system.
  
  Fig 2: Identifying Underdrive Clutch - 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 6.
    
    Fig 3: Identifying Underdrive Clutch - 5A/T
    Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
STEP 6. 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.