Inspection Procedure 17
INSPECTION PROCEDURE 17Deceleration Shock
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
STEP 1. Using scan tool MB991502, read the diagnostic trouble code (DTC).
CAUTION: To prevent damage to the scan tool, turn the ignition switch "OFF" before connecting or disconnecting the scan tool.
If DTC is not output, go to Step 2.
If DTC is output, refer to Inspection Chart for Diagnostic Trouble Code.
STEP 2. Check the idle air control (IAC) motor operation sound.
NOTE: Disconnecting the engine coolant temperature sensor connector and connecting the harness side of The connector to another engine coolant temperature sensor that is at 20°C (68°F) or below is also okay.
(1) Check that the engine coolant temperature is 20°C (68°F) or below.
(2) Check the operation sound of the IAC motor can be heard after the ignition is switched "ON" (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.
STEP 3. Using scan tool MB991502, check data list.
CAUTION: To prevent damage to the scan tool, turn the Ignition switch "OFF" before connecting or disconnecting the scan tool.
(1) Check the following items in the data list.
Refer to Data List Reference Table.
a. Item 14: Throttle Position Sensor.
b. Item 26: Closed Throttle Position Switch.
If the checks above do not meet the specifications, repair or replace.
If the checks above meet the specifications, clean the throttle valve area.
Then after replacing or cleaning, confirm that the malfunction symptom is eliminated.