Inspection Procedure 9: Hunting (Repeated Acceleration and Deceleration) Occurs at the Set Vehicle Speed < CVT. >: 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, diagnose the CAN bus line. 
   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 (Refer to HOW TO ERASE DIAGNOSTIC TROUBLE CODES  ).
   2. Turn the ignition switch to the "ON" position.
   3. Diagnose the CAN bus line (Refer to HOW TO ERASE DIAGNOSTIC TROUBLE CODES  ).

   Q: Is the check result satisfactory? 

   1. YES:  Go to Step 2.
   2. NO:  Repair the CAN bus lines (Refer to CAN BUS DIAGNOSTICS TABLE ). Then go to  Step 6.
      Fig 1: Connecting Special Tool MB991910 To Data Link Connector

      Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
2. STEP 2. Using scan tool MB991958, check for CVT system DTC. 
   1. Connect scan tool MB991958 to the data link connector (Refer to HOW TO ERASE DIAGNOSTIC TROUBLE CODES  ).
   2. Turn the ignition switch to the "ON" position.
   3. Check for CVT system DTC (Refer to DIAGNOSTIC FUNCTION ).

   Q: Is any DTC set? 

   1. YES:  Repair the CVT system (Refer to DIAGNOSTIC TROUBLE CODE TABLE ). Then go to  Step 6.
   2. NO:  Go to Step 3.
3. STEP 3. Using scan tool MB991958, check for MFI system DTC. 
   1. Connect scan tool MB991958 to the data link connector (Refer to HOW TO ERASE DIAGNOSTIC TROUBLE CODES  ).
   2. Turn the ignition switch to the "ON" position.
   3. Check for MFI system DTC (Refer to DIAGNOSTIC FUNCTION ) < 2.0L ENGINE Non-turbo > or (Refer to DIAGNOSTIC FUNCTION ) < 2.4L ENGINE >.

   Q: Is any DTC set? 

   1. YES:  Repair the MFI system (Refer to DIAGNOSTIC TROUBLE CODE TABLE ) < 2.0L ENGINE Non-turbo > or (Refer to DIAGNOSTIC TROUBLE CODE TABLE ) < 2.4L ENGINE >. Then go to  Step 6.
   2. NO:  Go to Step 4.
4. STEP 4. Using scan tool MB991958, check data list item 04: Vehicle speed. 
   1. Connect scan tool MB991958 to the data link connector (Refer to HOW TO ERASE DIAGNOSTIC TROUBLE CODES  ).
   2. Turn the ignition switch to the "ON" position.
   3. Set scan tool MB991958 to data reading mode for cruise control system (Refer to HOW TO ERASE DIAGNOSTIC TROUBLE CODES  ).
      • Item 04: Vehicle speed.

   Q: Is the check result satisfactory? 

   1. YES:  Go to Step 5.
   2. NO:  Replace the ECM [Refer to ENGINE CONTROL MODULE (ECM) ] < 2.0L ENGINE Non-turbo > or [Refer to ENGINE CONTROL MODULE (ECM) ] < 2.4L ENGINE >. When the ECM is replaced, register the encrypted code (Refer to ID registration procedure manual - ID codes registration judgement table) < Vehicle with WCM installed >. Then go to  Step 6.
5. STEP 5. Check the symptoms. 

   Q: Does hunting occur? 

   1. YES:  Replace the ECM [Refer to ENGINE CONTROL MODULE (ECM) ] < 2.0L ENGINE Non-turbo > or [Refer to ENGINE CONTROL MODULE (ECM) ] < 2.4L ENGINE >. When the ECM is replaced, register the encrypted code (Refer to ID registration procedure manual - ID codes registration judgement table) < Vehicle with WCM installed >. Then go to Step 6.
   2. NO:  It can be assumed that this malfunction is intermittent (Refer to HOW TO COPE WITH INTERMITTENT MALFUNCTION ).
6. STEP 6. Check the symptoms. 

   Q: Does hunting occur? 

   1. YES:  Return to  Step 1.
   2. NO:  The procedure is complete.