Inspection Procedure 17
COMMENT- There may be a sudden change in air flow through the IAC, causing the vehicle to decelerate rapidly for an instant.
TROUBLESHOOTING HINTS
The most likely causes for this case:
- Malfunction of the IAC system.
DIAGNOSIS
Required Special Tool:
MB991502: Scan Tool (MUT-II)
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 1. 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 2.
If DTC is output, refer to Diagnostic Trouble Code Chart.
STEP 2. Check the idle air control (IAC) motor operation sound.
1. Check that the engine coolant temperature is 20°C (68°F) or below.
NOTE: If necessary you can disconnect the engine coolant temperature sensor connector and connect the harness side of the connector to another engine coolant temperature sensor that is at 20°C (68°F) or below
2. Check the operation sound of the IAC motor can be heard after the ignition is switched to "ON" position (but without starting the engine).
- An operation sound should heard. If a sound is heard, go to Step 3.
If no sound is heard, refer to DTC P0505 - Idle Control System Malfunction.
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 3. Using scan tool MB991502, check data list.
1. Connect scan tool MB991502 to the data link connector.
2. Turn the ignition switch to "ON" position.
3. Check the following items in the data list.
Refer to Data List Reference Table.
a. Item 14: Throttle Position Sensor.
If the checks above do not meet the specifications, repair or replace.
If the checks above meet the specifications, clean the throttle valve area.
After replacing or cleaning, confirm that the malfunction symptom is eliminated.