How to Perform an Idle Relearn on Your Infiniti Vehicle
If you’ve recently cleaned the throttle body on your Infiniti vehicle and are now experiencing a rough idle or high idle RPMs, you likely need to perform an idle relearn procedure. An idle relearn, also known as an idle air volume learning (IAVL), allows the engine control module (ECM) to relearn the correct idle position after the throttle body has been cleaned or replaced.
In this comprehensive guide, we’ll cover everything you need to know about performing an idle relearn on Infiniti vehicles, including which models it applies to, a step-by-step tutorial for the latest procedure, and troubleshooting tips.
Infiniti Models That Require an Idle Relearn
The idle relearn procedure applies to many Infiniti models from the early 2000s through today that use drive-by-wire electronic throttle control. This includes:
- Infiniti G35 (2003-2006)
- Infiniti G37 (2008-2013)
- Infiniti M35/M45 (2006-2010)
- Infiniti Q50 (2014-present)
- Infiniti Q60 (2014-present)
- Infiniti QX56 (2004-2010)
- Infiniti FX35/FX45 (2003-2008)
- Infiniti EX35 (2008-2012)
- Infiniti JX35 (2012-2013)
- Infiniti QX60 (2014-present)
If you have one of these Infiniti models and have recently cleaned the throttle body, you will likely need to perform the idle relearn for the engine to idle properly again.
Latest Idle Relearn Tutorial
Here is the most up-to-date procedure for performing an idle relearn on Infiniti vehicles:
- Warm up the engine to normal operating temperature. You can do this by letting the engine idle or driving the vehicle for about 15 minutes.
- Turn the ignition off and wait at least 10 seconds.
- Make sure the accelerator pedal is fully released.
- Turn the ignition on (do not start the engine) and wait 3 seconds.
- Fully depress the accelerator pedal and hold for 10 seconds until the check engine light starts blinking.
- Within 3 seconds of the check engine light blinking, fully release the accelerator pedal.
- Start the engine and let it idle for about 20 seconds.
- Rev the engine a few times to around 2000-3000 RPM and make sure the idle speed returns to normal (around 650-700 RPM in park or neutral).
- If the idle is still not correct, turn the engine off and repeat steps 2-8.
Some additional tips:
- Make sure the battery is fully charged before starting the procedure. A weak battery can cause the relearn to fail.
- Do not touch the accelerator pedal once the relearn procedure has started until instructed to do so.
- The check engine light blinking indicates the ECM has entered relearn mode. If it doesn’t blink, retry the procedure.
- It may take a few drive cycles for the idle to fully stabilize after the relearn procedure. If the idle remains high after a day or two, there may be another underlying issue.
Troubleshooting Infiniti Idle Relearn Issues
If you’ve tried the idle relearn procedure multiple times and the idle is still surging or incorrect, here are a few things to check:
Vacuum Leaks
A vacuum leak can cause the ECM to set a lean code and idle poorly. Check all the vacuum lines, especially those going to the intake manifold, for cracks or loose connections. Spray carb cleaner around suspected leak areas while the engine is idling and see if the idle changes.
MAF Sensor
A dirty or failing mass airflow (MAF) sensor can cause poor idle quality. Try cleaning the MAF sensor with MAF cleaner spray or electrical contact cleaner. If that doesn’t help, the MAF sensor may need to be replaced.
Throttle Body
Make sure the throttle body was cleaned properly and the throttle plate moves freely. If the throttle body is sticking or gummed up, the idle relearn will not work correctly. The throttle body may need to be cleaned again or replaced if damaged.
Idle Air Control Valve
The idle air control (IAC) valve regulates the engine idle speed. If it is sticking or gummed up, it can cause idle issues. Try cleaning the IAC valve with throttle body cleaner. It may need to be replaced if faulty.
ECM Issues
In rare cases, there may be an issue with the ECM itself, such as corrupted idle data or a failing circuit board. An Infiniti dealer or specialist shop can test the ECM for faults.
The Importance of Regular Throttle Body Maintenance
The throttle body is a critical component of the air intake system that controls airflow into the engine. Over time, carbon deposits can build up on the throttle plate and bore, causing airflow restrictions and idle issues. This is especially common on direct injection engines.
To prevent throttle body buildup and idle problems, it’s important to clean the throttle body every 50,000 to 75,000 miles or as needed. Cleaning the throttle body involves removing it from the engine, spraying it down with throttle body cleaner, and scrubbing off the carbon deposits.
When reinstalling the throttle body, be careful not to damage the throttle position sensor or motor. It’s also critical to perform the idle relearn procedure afterwards to restore proper idle.
Regular throttle body maintenance, along with other tune-up items like replacing the air filter, spark plugs, and cleaning the MAF sensor, can go a long way in preventing drivability issues down the road. It’s much easier to be proactive than to deal with a rough idle later.
Final Words from Boss Erwin
In summary, performing an idle relearn is necessary after cleaning the throttle body on many Infiniti vehicles to restore proper idle. The procedure involves depressing the accelerator pedal in a specific sequence to trigger the ECM to relearn the idle position.
If the idle relearn doesn’t work after a few attempts, there may be an underlying issue like a vacuum leak, dirty MAF sensor, or faulty idle air control valve that needs to be addressed. Regular throttle body maintenance every 50,000-75,000 miles is important to prevent carbon buildup and idle issues in the first place.