INSPECTION PROCEDURE 1: Throttle Valve Will Not Fully Open or Close: Diagnosis

Required Special Tool: 

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

1. STEP 1. Using scan tool MB991958, read the diagnostic trouble code (DTC). 
   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. Ensure that the ignition switch is at the "LOCK" (OFF) position.
   2. Start up the personal computer.
   3. Connect special tool MB991827 to special tool MB991824 and the personal computer.
   4. Connect special tool MB991910 to special tool MB991824.
   5. Connect special tool MB991910 to the data link connector.
   6. Turn the power switch of special tool MB991824 to the "ON" position.
      NOTE: When special tool MB991824 is energized, special tool MB991824 indicator light will be illuminated in a green color.
   7. Start the MUT-III system on the personal computer.
   8. Turn the ignition switch to the "ON" position.
   9. Check for MFI system diagnostic trouble code. Refer to MFI DIAGNOSISMULTIPORT FUEL INJECTION (MFI) DIAGNOSIS - 2.4L or MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS - 3.8L .
   10. Turn the ignition switch to the "LOCK" (OFF) position, and then remove scan tool MB991958 in the reverse order of installation.

   Q: Is any DTC set? 

   1. YES:  Refer to DIAGNOSTIC TROUBLE CODE CHARTMULTIPORT FUEL INJECTION (MFI) DIAGNOSIS - 2.4L or MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS - 3.8L .
   2. NO:  Go to Step 2.
      Fig 1: Connecting Special Tool Mb991910 To Data Link Connector

      Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
2. STEP 2. Retest the system. 

   Q: Does the throttle valve fully open and close? 

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