Diagnostic Procedure

If idle air volume learning cannot be performed successfully, proceed as follows: 

1. Check that throttle valve is fully closed. 
2. Check PCV valve operation. 
3. Check that downstream of throttle valve is free from air leakage. 
4. When the above three items check out OK, engine component parts and their installation condition are questionable. Check and eliminate the cause of the incident. 
5. If any of the following conditions occur after the engine has started, eliminate the cause of the incident and perform Idle Air Volume Learning again: 
   • Engine stalls. 
   • Incorrect idle.