Idle Air Control Valve Closing Coil Circuit Malfunction (Nissan)
What does P1510 mean?
The P1510 code means the vehicle's onboard diagnostic system has detected: Idle Air Control Valve Closing Coil Circuit Malfunction (Nissan). This is a moderate severity code.
Common Symptoms
- Idle speed too high
- Check Engine Light illuminated
- Engine does not return to normal idle after revving
- Vehicle creeps forward at stops
- Idle fluctuates between high and normal
Probable Causes (Ranked by Likelihood)
- Faulty IACV closing coil Very High
- Corroded IACV connector High
- Open circuit in the closing coil wiring Moderate
- Carbon deposits preventing valve closure Moderate
- ECU output circuit failure Low
Step-by-Step Diagnostic Procedure
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Measure the IACV closing coil resistance. Typical Nissan IACV resistance is 7 to 10 ohms.
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Inspect the IACV connector for corrosion or loose terminals.
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Remove the IACV and clean it with throttle body cleaner. Check for free movement.
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Test the wiring from the ECU to the IACV for continuity and shorts.
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Command the IACV with a scan tool and observe if idle speed drops when the closing coil is energized.
Frequently Asked Questions
What is the IACV closing coil?
Nissan uses a two-coil IACV with an opening coil and a closing coil. The closing coil reduces the idle air bypass to lower RPM. A failed closing coil means the valve cannot reduce idle speed.
Can cleaning fix this code?
If the coil tests good electrically but the valve is stuck due to carbon, cleaning can resolve it. If the coil resistance is out of specification, the IACV must be replaced.
Is this a recall or common issue on Nissan?
It is a common issue on older Nissan vehicles with cable-operated throttles. There is no recall, but many shops are familiar with this repair on Frontier, Xterra, and Pathfinder models.