How to Perform a Throttle Relearn on Your Acura

How to Perform a Throttle Relearn on Your Acura

If you’ve recently disconnected the battery, cleaned the throttle body, or replaced the ECM/PCM on your Acura, you may need to perform a throttle relearn procedure. This process allows the engine control module to relearn the idle and throttle settings for optimal performance and fuel efficiency. In this guide, we’ll walk through the detailed steps to do a throttle relearn on various Acura models.

What is a Throttle Relearn and When is it Needed?

A throttle relearn, also known as an idle relearn, is a procedure that recalibrates the vehicle’s throttle body and engine control module (ECM) or powertrain control module (PCM). The ECM/PCM needs to learn the minimum idle speed and throttle position to properly control the engine idle and throttle response.

You should perform a throttle relearn if you’ve done any of the following:

• Disconnected or replaced the battery
• Cleaned the throttle body
• Replaced the throttle body, ECM, or PCM
• Reflashed or updated the ECM/PCM

Some signs that your Acura may need a throttle relearn include:

• Rough or unstable idle
• Illuminated check engine light
• Reduced fuel economy
• Sluggish throttle response

Throttle Relearn Procedure for Acura Vehicles

The general process to perform a throttle relearn is similar across most Acura models from the early 2000s through today, including the MDX, RDX, TLX, ILX, RLX, and NSX. However, always consult your owner’s manual for model-specific instructions.

Here are the steps to do a throttle relearn on your Acura:

1. Ensure all electrical accessories are turned off, including the radio, A/C, headlights, etc.
2. Turn the ignition to the ON position (do not start the engine) and wait for 2 seconds.
3. Start the engine and let it idle in park for 2-3 minutes until it reaches operating temperature. The radiator fans may cycle on and off during this time.
4. With your foot on the brake, quickly press the accelerator pedal to the floor and release it immediately. Repeat this 5 times within 5 seconds.
5. Let the engine idle for 7 minutes with the throttle fully closed. Do not press the accelerator during this time. If the radiator fans come on, do not include that time as part of the 7 minutes.
6. Turn off the engine and wait 60 seconds. The ECM/PCM will now be reset with the relearned values.
7. Restart the engine and let it idle for 2 minutes in park to complete the relearn process. Then drive the vehicle normally.

Some newer Acura models like the 2019+ RDX have a slightly different procedure:

1. With the engine off, press and hold the accelerator pedal for 10 seconds.
2. Turn the ignition on (do not start) and wait 2 seconds.
3. Release the accelerator pedal.
4. Press the accelerator pedal to the floor quickly 5 times within 5 seconds.
5. Start the engine and let it idle for 5-7 minutes until the radiator fans cycle on.
6. Turn off the engine and wait 60 seconds to complete the relearn.

Tips for a Successful Throttle Relearn

To ensure the throttle relearn procedure works properly on your Acura, keep these tips in mind:

• Always perform the relearn in an open, well-ventilated area, not in a garage.
• Make sure the battery is fully charged and the charging system is working properly.
• Do not touch the accelerator pedal during the 5-7 minute idle relearn period.
• If the check engine light comes on during the relearn, turn off the engine and restart the procedure from the beginning.
• For keyless push-button start models, press and hold the start button for 2 seconds without your foot on the brake to turn the ignition on.
• If the idle is still rough or unstable after the relearn, there may be an underlying issue that needs to be diagnosed.

The Importance of Proper Throttle Operation

The throttle body is a key component that controls the amount of air entering the engine, which directly impacts performance, fuel economy, and emissions. Over time, carbon deposits can build up on the throttle plate and cause issues like a rough idle, stumbling, or stalling.

Cleaning the throttle body and performing a throttle relearn allows the ECM to compensate for these changes and restore proper operation. It’s a relatively simple procedure that can often resolve idle issues without needing more extensive diagnostics or repairs.

When to See a Professional

While a throttle relearn is a straightforward process that many DIYers can perform at home, there are some cases where it’s best to consult a professional Acura technician:

• If the check engine light remains on after the relearn with throttle-related trouble codes
• The idle is still rough or the car is stalling after the relearn
• You’re unsure about performing the procedure correctly
• There are other underlying issues with the throttle body, sensors, or wiring

A skilled technician will have the proper diagnostic tools and expertise to pinpoint any problems and ensure your Acura’s throttle and idle control systems are operating as designed.

Final Words from Boss Erwin

Performing a throttle relearn is an important part of maintaining your Acura’s engine performance and driveability. By following the steps outlined in this guide, you can reset the idle and throttle settings after a battery disconnect, ECM replacement, or throttle body cleaning.

If you’re still experiencing issues after the relearn, don’t hesitate to bring your car to a trusted Acura service center for further diagnosis. With proper care and maintenance, your Acura’s throttle and engine management systems will continue to deliver the responsive, efficient performance you expect for many miles to come.