Inspection Procedure 13

INSPECTION PROCEDURE 13: The engine stalls when decelerating.

COMMENT

- Abnormal air/fuel ratio or other similar defects due to insufficient intake air volume and defective EGR system is suspected to be the causes.

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

- Malfunction of the ignition system.

- Malfunction of the purge control system.

- Malfunction of the EGR system.

- Malfunction of the ECM.

DIAGNOSIS

Required Special Tools:

- MB991958: Scan Tool (M.U.T.-III Sub Assembly)
- MB991824: V.C.I.

- MB991827: USB Cable

- MB991910: Main Harness A

STEP 1. Check if the EGR valve sounds during initialization.

Q. Is the initialization sound heard in the EGR valve?

YES Go to Step 2.
NO EGR Valve (Stepper Motor) Check.
STEP 2. 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)Connect scan tool MB991958 to the data link connector.
(2)Turn the ignition switch to the "ON" position.
(3)Read the DTC.
(4)Turn the ignition switch to the "LOCK" (OFF) position.

Q. Is any DTC set?

YES Refer to Diagnostic Trouble Code Chart Multiport Fuel Injection (MFI).

NO Go to Step 3.

STEP 3. Engine stall reproduction test.

Q. Does the engine stall during the decrease in engine speed after running?

YES Go to Step 5.
NO Go to Step 4.
STEP 4. Using scan tool MB991958, check actuator test.

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

(2)Check the following item in the actuator test. Refer to Actuator Test Reference Table Actuator Test Reference Table.
1. Item 10: Evaporative Emission Purge Solenoid.

(3)Turn the ignition switch to the "LOCK" (OFF) position.

Q. Is the actuator operating properly?

YES Go to Step 5.
NO Repair or replace it. Then confirm that the malfunction symptom is eliminated.
STEP 5. Using scan tool MB991958, check data list.

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

(2)Check the following items in the data list. Refer to Data List Reference Table Data List Reference Table.
2. Item 13: Throttle Position Sensor (main).

3. Item 15: Throttle Position Sensor (sub).

4. Item 11: Accelerator Pedal Position Sensor (main).

5. Item 12: Accelerator Pedal Position Sensor (sub).

(3)Turn the ignition switch to the "LOCK" (OFF) position.

Q. Are they operating properly?

YES Go to Step 6.
NO Repair or replace it. Then confirm that the malfunction symptom is eliminated.
STEP 6. Check the spark plugs.

Procedures.

Q. Are there any abnormalities?

YES Replace the spark plug. Then confirm that the malfunction symptom is eliminated.
NO Check the ignition coil.