Idle Air Control System at Adaptive Limit
2009-2012 Ford Flex 3.5L V6 🇨🇦
Description
The IAC system has reached its maximum adaptive correction and can no longer maintain proper idle speed. This indicates the IAC is working at its limit trying to compensate for another issue.
Symptoms
- Check Engine Light
- Idle speed too high or too low
- Rough idle
- Stalling
Common Causes
- Large vacuum leak
- Carbon buildup restricting airflow
- Faulty IAC valve
- Throttle body needs cleaning
- Air leak in intake system
Diagnostic Steps
- Check for vacuum leaks using smoke test
- Clean throttle body and IAC passage
- Monitor IAC duty cycle — near 0% or 100% indicates problem
- Inspect for air leaks in intake system
Repair Notes
Find and fix the root cause (usually vacuum leak or carbon buildup). Clean throttle body. Replace IAC if valve itself is faulty.
Related Codes
Other Powertrain Codes
- P0001Fuel Volume Regulator Control Circuit/Open
- P0002Fuel Volume Regulator Control Circuit Range/Performance
- P0003Fuel Volume Regulator Control Circuit Low
- P0004Fuel Volume Regulator Control Circuit High
- P0010Intake Camshaft Position Actuator Circuit/Open Bank 1
- P0011Intake Camshaft Position Timing Over-Advanced Bank 1
- P0012Intake Camshaft Position Timing Over-Retarded Bank 1
- P0013Exhaust Camshaft Position Actuator Circuit/Open Bank 1
- P0014Exhaust Camshaft Position Timing Over-Advanced Bank 1
- P0015Exhaust Camshaft Position Timing Over-Retarded Bank 1
P1505 on Other Vehicles
Common Questions
What does code P1505 mean on a 2009-2012 Ford Flex?
P1505 stands for "Idle Air Control System at Adaptive Limit". The IAC system has reached its maximum adaptive correction and can no longer maintain proper idle speed. This indicates the IAC is working at its limit trying to compensate for another issue.
What are the symptoms of P1505 on a Ford Flex?
Common symptoms of P1505 include: Check Engine Light, Idle speed too high or too low, Rough idle, Stalling.
What causes P1505 on a 2009-2012 Ford Flex?
Common causes of P1505 include: Large vacuum leak, Carbon buildup restricting airflow, Faulty IAC valve, Throttle body needs cleaning, Air leak in intake system.