Inspection Procedure 14

COMMENT
- The intake air volume may be insufficient due to a defective idle air control motor system.

TROUBLESHOOTING HINTS
The most likely causes for this case:
- Malfunction of the IAC system.

DIAGNOSIS
Required Special Tool:
MB991502: Scan Tool (MUT-II)

STEP 1. Check if the battery terminal is disconnected
Has the battery terminal been disconnected lately?

If no, go to Step 2.

If yes, start the engine and let it run at idle for approximately 10 minutes after warm-up. Then, if a malfunction occurs, go to Step 2.

CAUTION: To prevent damage to scan tool MB991502, always turn the ignition switch to "LOCK" (OFF) position before connecting or disconnecting scan tool MB991502.




STEP 2. Using scan tool MB991502, read the diagnostic trouble code (DTC).
1. Connect scan tool MB991502 to the data link connector.
2. Turn the ignition switch to "ON" position.
3. Read the DTC.

If DTC is not output, go to Step 3.

If DTC is output, refer to Diagnostic Trouble Code Chart.




STEP 3. Using scan tool MB991502, check data list and actuator test.
1. Check the following items in the data list.
Refer to Data List Reference Table.
a. Item 14: Throttle Position Sensor.

2. Check the following items in the actuator test.
Refer to Actuator Test Reference Table.
a. Item 10: EGR Solenoid.

If the checks above meet the specifications, go to Step 4.

If the checks above do not meet the specifications, repair or replace. Then confirm that the malfunction symptom is eliminated.




STEP 4. Using scan tool MB991502, check data list item 45: Idle Air Control Position.
1. Start the engine and run at idle.
2. Set scan tool MB991502 to the data reading mode for item 45, Idle Air Control Position. - The idle air control motor should drop to the 0 - 2 position during deceleration (from 1,000 r/min or more).

If the idle air control motor does not drop to the position, go to Step 5.

If the idle air control motor drops to that position, refer to DTC P0500 - Vehicle Speed Sensor Malfunction.

STEP 5. Check the following items.
1. Check the following items, and repair, replace or clean the defective sections.
a. Check the ignition coil, spark plugs, spark plug cables.
b. Clean the throttle valve area.

Then replacing, cleaning or adjusting, confirm that the malfunction symptom is eliminated.