How To Reset Harley-Davidson IAC Sensor (Step-By-Step)

Compare Motorcycle Insurance!
Motorcycle Insurance - Compare and Save up to 40%
It's fast and easy to compare motorcycle insurance quotes! Get My Quotes! Motorcycle Image

If your Harley is not idling properly or its idle rpm is too low or high, the Idle Air Control (IAC) must be serviced. In this article, I’ll explain how to reset your Harley-Davidson Idle Air Control sensor to recalibrate the idle rpm of the engine.

What Does IAC Sensor Do?

Harley Davidson IAC Sensor

If you open the air filter cabinet, you’ll see a small hole near the throttle valve. When you twist the throttle bar, the valve opens, and air enters the combustion chamber.

At the same time, the throttle position sensor sends a signal to the ECM, and the fuel injector atomizes the fuel and injects it into air entering the combustion chamber.

When you fully release the throttle bar, the throttle valve fully closes, and no air enters the combustion chamber. In this case, the engine should immediately die.

But Harley provides a small hole (called an IAC valve) that allows air to enter when the motorcycle idles.

Also Read: Motorcycle won’t idle without throttle (Fixed)

How To Service Idle Air Control (IAC) Valve

Over time, the IAC valve gets choked with dust particles, and its idle rpm drops too low. That’s why cleaning and servicing the idle air control valve regularly is important. After cleaning and servicing, you need to reset the IAC sensor to calibrate the idle rpm.

Harley Davidson IAC Cleaning

Follow these steps to clean and service a Harley’s IAC valve:

  1. Unscrew the air filter cabinet.
  2. Remove the air filter from the cabinet.
  3. Spray throttle body and air intake cleaner. (I’m using this product)
  4. Wait for 20 to 30 seconds and wipe with a cotton towel.
  5. Again, spray the throttle body and air intake cleaner and wipe everything with a cotton towel.
  6. After cleaning the throttle valve, spray the cleaner into the IAC valve.
  7. Repeat this process several times until all dust is removed.
  8. Reassemble everything and recalibrate the IAC sensor.

Also Read: How often to change motorcycle air filter

How To Reset Harley-Davidson IAC Sensor

After cleaning and servicing, you need to recalibrate the IAC sensor to maintain the optimum idle rpm of your motorcycle.

Follow these steps to reset Harley’s IAC sensor:

  1. Fully release the throttle bar, turn on the ignition, and set the kill switch to RUN position.
  2. Let the odometer needle completely rotate and return back to the zero position.
  3. Without starting the engine, turn off the ignition switch.
  4. Wait for 10 seconds and repeat the same process.
  5. Repeat it three times to fully re-calibrate the IAC sensor.

The Idle Air Control sensor will re-calibrate with every start-up cycle. After repeating this process 3 times, start the engine and let it warm up for 5 minutes.

That’s it. Your Harley’s IAC valve is now re-calibrated, and your motorcycle is ready for a long ride.


The dust particles accumulate around the IAC valve, which disturbs the idle rpm of your Harley-Davidson. You can easily service and re-calibrate your IAC valve at home. If you face any problems related to idling, feel free to ask in the comment box.

Similar Posts

Leave a Reply

Your email address will not be published. Required fields are marked *