Inspection Procedure 1

Inspection Procedure 1: Throttle Valve will not Fully Open or Close

COMMENT

The throttle body or accelerator pedal position sensor (APP sensor) is suspected.

TROUBLESHOOTING HINTS (The most likely causes for this case:)

- Malfunction of the throttle body.
- Malfunction of the APP sensor.
- Malfunction of the engine control module (ECM).

DIAGNOSTIC PROCEDURE

STEP 1. Using scan tool MB991958, read the MFI system diagnostic trouble code (DTC).

(1)
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.

Connect scan tool MB991958 to the data link connector Reading and Clearing Diagnostic Trouble Codes).

(2)Turn the ignition switch to the "ON" position.

(3)Set scan tool MB991958 to check for MFI system DTC Reading and Clearing Diagnostic Trouble Codes).

Q. Is any DTC set?

YES Repair the MFI system Multiport Fuel Injection (MFI)) . Then go to Step 2.
NO Go to Step 2.
STEP 2. Check the symptom.

Q. Does the throttle valve fully open and close?

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