Idle Control System Malfunction
Table of contents
- Possible Causes
- How To Fix
- Tech Notes
- Cost To Diagnose
- When is the code detected
- Possible Symptoms
- Description
P0511 SCION Possible Causes
- Open or short in IAC valve circuit
- IAC valve stuck or closed
- ECM
How do I fix code P0511 SCION?
Check the “Possible Causes” listed above. Visually inspect the related wiring harness and connectors. Check for damaged components and look for broken, bent, pushed out, or corroded connector’s pins.
Tech Notes
- Before replacing any parts, try cleaning the Idle air control valve.
Cost of diagnosing the P0511 SCION code
The cost of diagnosing the P0511 SCION code is 1.0 hour of labor. The auto repair labor rates vary by location, your vehicle’s make and model, and even your engine type. Most auto repairs shops charge between $75 and $150 per hour.
When is the code detected
The Engine Control Module (ECM) regulates the idle speed by opening and closing the throttle valve using the ETCS. The ECM concludes that the idle speed control ECM function is malfunctioning if: 1) the actual idle RPM varies more than the specified amount five times or more during a drive cycle, or 2) a learning value of the idle speed control remains at the maximum or minimum five times or more during a drive cycle. The ECM will turn on the engine light and set P0511 code.
Example: If the actual idle RPM varies from the target idle RPM by more than 200* rpm five times during a drive cycle, the ECM will turn on the MIL and will set a DTC.
Possible Symptoms
- Engine Light ON (or Service Engine Soon Warning Light)
- Engine hard to start
- Rough or erratic idle speed
P0511 SCION Description
The Idle Air Control (IAC) valve, a rotary solenoid type, is located under the throttle body. Intake air bypassing the throttle valve flows into the IAC valve through a passage. The valve regulates the volume of intake air that bypasses the throttle valve and allows the engine idling speed to be controlled. The IAC valve is used by the ECM to perform idle-up and its feedback signal is used as one factor in target engine idling speed regulation.