How is the idle speed of a car controlled?

How is the idle speed of a car controlled?

Idle speed is controlled through fine adjustment of the amount of air which by-passes the throttle valve via Idle Air Control Valve IACV) and Auxiliary Air Control AAC) Valve. The IACV-AAC valve changes the opening of the air by-pass passage to control the amount of auxiliary air.

What does the idle air control valve do?

The IAC (Idle Air Control) valve controls the idle speed of the engine. At idle the throttle plate is closed, of course.

What are the symptoms of idle air control malfunction?

Symptoms may include: 1 MIL (Malfunction Indicator Lamp) illumination. 2 Engine stalls and may not idle unless throttle is depressed. 3 Intermittently stalls when letting off the throttle. 4 Engine may idle too high.

When to use the p0505 idle speed code?

The P0505 code is set when the IACV-AAC valve does not operate properly. This system automatically controls engine idle speed to a specified level. Idle speed is controlled through fine adjustment of the amount of air which by-passes the throttle valve via Idle Air Control Valve IACV) and Auxiliary Air Control AAC) Valve.

How does idle work on a Honda Civic?

The idle also smoothes out when a/c load is present(but also at a higher rpm than normal). The MAP sensor, fast idle valve, and idle air control valve all checked good with multimeter to the sensor and back to the PCM.Have not checked TPS or coolant sensor(because it functioned normal by needle on instrument panel).

What causes the idle control system malfunction code?

All our repairs are backed by our 12-month / 12,000-mile warranty. P0505 is an OBD-II generic code that the engine control module (ECM) determined the engine idle control system is not managing the idle to stay in specification. The idle is too high or goes too low. What causes the P0505 code?

Idle speed is controlled through fine adjustment of the amount of air which by-passes the throttle valve via Idle Air Control Valve IACV) and Auxiliary Air Control AAC) Valve. The IACV-AAC valve changes the opening of the air by-pass passage to control the amount of auxiliary air.

The IAC (Idle Air Control) valve controls the idle speed of the engine. At idle the throttle plate is closed, of course.