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

Required Special Tools: 

• MB991958: Scan Tool (MUT-III Sub Assembly)
  • MB991824: V.C.I.
  • MB991827: MUT-III USB Cable
  • MB991910: MUT-III Main Harness A

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. (Refer to DIAGNOSTIC FUNCTION  ).
      Fig 1: Connecting Scan Tool To Data Link Connector

      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 MFI DIAGNOSIS - DIAGNOSTIC FUNCTION - 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  : Diagnose the MFI control system. (Refer to MFI DIAGNOSIS - DIAGNOSTIC TROUBLE CODE CHART ). Then go to  Step 3.
   2. NO  : 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. (Refer to DIAGNOSTIC FUNCTION  ).
      Fig 2: Connecting Scan Tool 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 A/T DIAGNOSIS - DIAGNOSTIC FUNCTION - 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  : Diagnose the A/T system. (Refer to A/T DIAGNOSIS - DIAGNOSTIC TROUBLE CODE CHART ). Then go to Step 3.
   2. NO  : Replace the PCM. [Refer to POWER CONTROL MODULE (PCM) ]. Then go to Step 3.
3. STEP 3. Using scan tool MB991958, read the diagnostic trouble codes. 
   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 DIAGNOSTIC FUNCTION  ).
      Fig 3: Connecting Scan Tool To Data Link Connector

      Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
   2. Turn the ignition switch to the "ON" position.
   3. Check for auto-cruise control system diagnostic trouble code. (Refer to DIAGNOSTIC FUNCTION  ).
   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.