Idle Air Control System Underspeed
2014-2021 Mazda Mazda6 2.5L I4 🇨🇦
Description
The engine idle speed is too low. The PCM detects that idle RPM is below the target and the IAC system cannot increase it sufficiently to prevent stalling.
Symptoms
- Check Engine Light
- Idle speed too low
- Engine stalling at idle
- Engine dies when put in gear or when A/C turns on
Common Causes
- Carbon buildup in IAC passages restricting airflow
- Faulty IAC valve stuck closed
- Dirty throttle body
- Engine mechanical issue reducing idle air
- Restricted IAC passage
Diagnostic Steps
- Clean IAC valve and passages
- Clean throttle body bore
- Test IAC valve operation with scan tool
- Check for restricted IAC air passage
- Verify engine mechanical condition
Repair Notes
Clean the throttle body and IAC passages; replace the IAC valve if it is stuck closed.
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
P1507 on Other Vehicles
Common Questions
What does code P1507 mean on a 2014-2021 Mazda Mazda6?
P1507 stands for "Idle Air Control System Underspeed". The engine idle speed is too low. The PCM detects that idle RPM is below the target and the IAC system cannot increase it sufficiently to prevent stalling.
What are the symptoms of P1507 on a Mazda Mazda6?
Common symptoms of P1507 include: Check Engine Light, Idle speed too low, Engine stalling at idle, Engine dies when put in gear or when A/C turns on.
What causes P1507 on a 2014-2021 Mazda Mazda6?
Common causes of P1507 include: Carbon buildup in IAC passages restricting airflow, Faulty IAC valve stuck closed, Dirty throttle body, Engine mechanical issue reducing idle air, Restricted IAC passage.