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

Required Special Tools:

MB991958: Scan Tool (MUT-III sub assembly)
- MB991824: Vehicle communication interface (V.C.I.)
- MB991827: MUT-III USB Cable
- MB991911: MUT-III Main Harness B

STEP 1. Check the accelerator pedal arm return spring.
Q: Is the accelerator pedal arm return spring damaged or deformed?

YES: Go to Step 2.

NO: Replace, then go to Step 4.
STEP 2. Clean the throttle body (Refer to THROTTLE BODY CLEANING ).
Q: Does the throttle valve fully open and close?

YES: The procedure is complete.

NO: Go to Step 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. 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 MB991911 to special tool MB991824.
5. Connect special tool MB991911 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 HOW TO READ AND ERASE DIAGNOSTIC TROUBLE CODE ).
10. Turn the ignition switch to the "LOCK" (OFF) position, and then remove scan tool MB991958 in the reverse order of installation.
  
  Fig 1: Connecting Scan Tool To Data Link Connector
  Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
Q: Is any DTC set?

YES: Refer to DIAGNOSTIC TROUBLE CODE CHART .

NO: Go to Step 4.
STEP 4. Retest the system.
Q: Does the throttle valve fully open and close?

YES: The procedure is complete.

NO: Return to Step 1.