Faulty idle air control valve (opening coil internally shorted or open); Damaged or corroded electrical connector at the IAC valve; Wiring harness issue such as a short to ground or an open circuit in the coil control wire; Poor connection at the engine control module (ECM) connector; Failed ECM driver for the IAC valve opening coil (rare)

DTC codes / Kia codes / P1505

P1505 · KiaIdle Air Control Valve Opening Coil Voltage Low

Q: What does code P1505 mean?

Idle Air Control Valve Opening Coil Voltage Low. The P1505 code on Kia vehicles indicates that the engine control module (ECM) has detected a low voltage condition on the opening coil circuit of the idle air control (IAC) valve. The ECM monitors the electrical current through the IAC valve's opening coil and sets this code when the voltage falls below the expected threshold, which can disrupt the valve's ability to maintain proper idle speed.

The P1505 code on Kia vehicles indicates that the engine control module (ECM) has detected a low voltage condition on the opening coil circuit of the idle air control (IAC) valve. The ECM monitors the electrical current through the IAC valve's opening coil and sets this code when the voltage falls below the expected threshold, which can disrupt the valve's ability to maintain proper idle speed.

SystemPowertrain

Code typeKia specific

SeverityMedium

Fix difficultyIntermediate

AreaVehicle speed, idle control and auxiliary inputs

Symptoms you may notice

Illuminated check engine light, often with no other noticeable symptoms
Rough or unstable idle, sometimes causing the engine to stall when coming to a stop
Idle speed that is too low or fluctuates up and down
Engine may hesitate or stumble during acceleration from idle
In some cases, the engine may idle too high if the valve sticks open

Common causes, most likely first

Faulty idle air control valve (opening coil internally shorted or open)
Damaged or corroded electrical connector at the IAC valve
Wiring harness issue such as a short to ground or an open circuit in the coil control wire
Poor connection at the engine control module (ECM) connector
Failed ECM driver for the IAC valve opening coil (rare)

How to diagnose and fix it

Inspect the IAC valve electrical connector for corrosion, loose pins, or damage and clean or repair as needed
Disconnect the IAC valve and measure the resistance of the opening coil with a multimeter, comparing to the manufacturer's specification
Check the wiring harness between the IAC valve and ECM for continuity and shorts to ground, repairing any damaged wires
Test the IAC valve operation by applying battery voltage to the opening coil terminals and observing valve movement
If the valve fails electrical tests, replace the idle air control valve
Clear the diagnostic trouble codes and perform an idle relearn procedure if required by the vehicle
If the code persists after all other checks, diagnose the ECM driver circuit or replace the ECM as a last resort

Don't overlook the IAC valve connector

A loose or corroded connector at the IAC valve is a frequent cause of this code, often overlooked when technicians focus on the valve itself.
The opening coil can fail intermittently, so resistance tests may pass when cold but fail when hot; testing the valve when the engine is at operating temperature can reveal the fault.
This code can be set by a wiring short to ground in the coil control circuit, which may also damage the ECM driver if not repaired promptly.
Some Kia models use an idle air control valve that is part of the throttle body assembly, so a faulty throttle body can trigger this code even if the valve itself is not serviceable separately.
A vacuum leak or dirty throttle body can cause idle issues that mimic a failed IAC valve, so always check for intake leaks and clean the throttle body before replacing parts.

Can I keep driving with P1505?

You can usually drive the vehicle with this code, but be prepared for idle instability that could cause stalling at low speeds. Avoid heavy traffic or situations where a stall would be dangerous, and have the fault diagnosed promptly to prevent further damage to the ECM or catalytic converter.

Tools that help

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Guidance is general and written for Kia vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.