DTC 2-3-3
2-3-3 IDLE AIR TRIMPrecondition for DTC
^ If the idle air trim is allowed to raise: [upper limit: 22 kg/h (48.5 lbs/h)] or lower: [lower limit: 8 kg/h (17.6 lbs/h)] the volume of air through the Idle Air Control (IAC) valve by too much to maintain the correct idling speed, DTC 2-3-3 is set.
Substitute values
^ None.
Fault sources
^ Upper limit:
- Clogged Air Cleaner (ACL) or air intake.
- Contact resistance in the connectors.
- Wrongly adjusted Throttle Body (TB).
- Defective IAC valve.
^ Lower limit:
- Air leakage.
- Contact resistance in connectors.
- Wrongly adjusted Throttle Body (TB).
- Defective IAC valve.
Fault symptoms
^ Idling speed too high or too low.
TESTING PROCEDURE
Status Message
^ Check current status message.
If Status message is: Upper Limit:
- Proceed to: UPPER LIMIT section below.
If Status message is: Lower Limit:
- Proceed to: LOWER LIMIT section below.
UPPER LIMIT
Checking the Throttle Position
^ Engine at idling speed.
^ Look up the DTC parameter.
^ Read off throttle position.
Throttle position should be 3° - 8° with the throttle shut.
If value is OK:
- Check the ACL and air intake.
If value is incorrect:
- Adjust the Throttle Body.
- Then clear DTCs and reset adaption.
Checking the Air Cleaner and Air Intake
^ Switch Ignition OFF.
^ Check that the ACL, air intake and hoses and pipes between the ACL and Throttle Body are not blocked. Check also the connectors for the IAC valve.
If OK:
- Check the IAC valve.
If blocked:
- Rectify as necessary.
- Then clear DTCs and reset adaption.
Checking the IAC Valve
^ Switch Ignition OFF.
^ Disconnect the IAC valve.
^ Connect an ohmmeter between connector 1 and 3 on the IAC valve.
The ohmmeter should show 18 - 28 ohms at +2O°C (68°F).
If value is OK:
- Check the IAC valve's control slide.
If value is incorrect:
- Test with a new IAC valve.
- Then clear DTCs and reset adaption.
Checking the IAC Valve's Control Slide
^ Switch Ignition OFF.
^ Remove the IAC valve.
^ Hold the valve at the connector, turn the valve quickly but carefully back and forth.
Listen for the sound of the slide striking.
CAUTION: The slide may under no circumstances be touched with a screwdriver or similar instrument, since this may scratch and thus damage it.
If the slide in the IAC valve strikes:
- Rectify the IAC valve's and ECM's connectors with regard to contact resistance and oxidation.
- Then clear DTCs and reset adaption.
If the slide in the IAC valve does not strike:
- Test with a new IAC valve.
- Then clear DTCs and reset adaption.
LOWER LIMIT
Checking the Throttle Position
^ Engine at idling speed.
^ Look up the DTC parameter.
^ Read off the throttle position.
Throttle position should be 3° - 8° with the throttle closed.
If value is OK:
- Check for air leakage.
If value is incorrect:
- Adjust the Throttle Body.
- Then clear DTCs and reset adaption.
Checking for Air Leakage
^ Switch Ignition OFF.
^ Check if there is any air leakage.
If there is no air leakage:
- Check the IAC valve.
If there is air leakage:
- Rectify as necessary.
- Then clear DTCs and reset adaption.
Checking the IAC Valve
^ Switch Ignition OFF.
^ Disconnect the IAC valve.
^ Connect an ohmmeter between connector 1 and 3 on the IAC valve.
The ohmmeter should show 18 - 28 ohms at +20°C (68°F).
If value is OK:
- Check the IAC valve's control slide.
If value is incorrect:
- Test with a new IAC valve.
- Then clear DTCs and reset adaption.
Checking the IAC Valve's Control Slide
^ Switch Ignition OFF.
^ Remove the IAC valve.
^ Hold the valve at the connector, turn the valve quickly but carefully back and forth.
Listen for the sound of the slide striking.
CAUTION: The slide may under no circumstances be touched by a screwdriver or other instrument, since this may scratch and therefore damage the slide.
If the IAC valve slide strikes:
- Rectify the IAC valve's and ECM's connectors with regard to contact resistance and oxidation.
- Then clear DTCs and reset adaption.
If the IAC valve does not strike:
- Test with a new IAC valve.
- Then clear DTCs and reset adaption.