DTC 23: Powertrain Control module (PCM) and Its Related Components: Diagnosis

Required Special Tool: 

• MB991958: Scan tool (MUT-III sub assembly)
  • MB991824: V.C.I.
  • MB991827: MUT-III USB cable
  • MB991911: MUT-III main harness B

1. STEP 1. Using scan tool MB991958, read the diagnostic trouble code. 
   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.
      Fig 1: Connecting Scan Tool MB991958

      Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
   2. Turn the ignition switch to the "ON" position.
   3. Check for MFI system diagnostic trouble code (Refer to HOW TO READ AND ERASE DIAGNOSTIC TROUBLE CODE ).
   4. Turn the ignition switch to the "LOCK" (OFF) position.
   5. Disconnect scan tool MB991958.

   Q: Is any DTC set? 

   1. YES:  Repair the MFI control system. (Refer to DIAGNOSTIC TROUBLE CODE CHART ). Then go to  Step 4.
   2. NO < M/T >:  Go to  Step 3.
   3. NO < A/T >:  Go to Step 2.
2. STEP 2. Using scan tool MB991958, read the diagnostic trouble code. 
   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.
      Fig 2: Connecting Scan Tool MB991958 To Data Link Connector

      Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
   2. Turn the ignition switch to the "ON" position.
   3. Check for A/T system diagnostic trouble code (Refer to HOW TO READ AND ERASE DIAGNOSTIC TROUBLE CODE ).
   4. Turn the ignition switch to the "LOCK" (OFF) position.
   5. Disconnect scan tool MB991958.

   Q: Is any DTC set? 

   1. YES:  Repair the automatic transaxle control system (Refer to DIAGNOSTIC TROUBLE CODE CHART ). Then go to  Step 4.
   2. NO:  Go to Step 3.
3. STEP 3. Using scan tool MB991958, read the diagnostic trouble code. 
   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.
      Fig 3: Connecting Scan Tool MB991958 To Data Link Connector

      Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
   2. Turn the ignition switch to the "ON" position.
   3. Use scan tool MB991958 to read the auto-cruise control system diagnostic trouble codes (Refer to P.17-126).
   4. Turn the ignition switch to the "LOCK" (OFF) position.
   5. Disconnect scan tool MB991958.

   Q: Is DTC 23 set? 

   1. YES:  Replace the ECM < M/T > or PCM < A/T > [Refer to ENGINE CONTROL MODULE (ECM) AND POWERTRAIN CONTROL MODULE (PCM) ]. Then go to Step 4.
   2. NO:  It can be assumed that this malfunction is intermittent (Refer to HOW TO COPE WITH INTERMITTENT MALFUNCTIONS ).
4. STEP 4. Using scan tool MB991958, read the diagnostic trouble code. 
   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.
      Fig 4: Connecting Scan Tool MB991958 To Data Link Connector

      Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
   2. Turn the ignition switch to the "ON" position.
   3. Use scan tool MB991958 to read the auto-cruise control system diagnostic trouble codes (Refer to HOW TO READ AND ERASE DIAGNOSTIC TROUBLE CODES ).
   4. Turn the ignition switch to the "LOCK" (OFF) position.
   5. Disconnect scan tool MB991958.

   Q: Is DTC 23 set? 

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