Can you start Acura MDX with dead key fob?

Yes—Acura’s MDX with push-button start includes a built-in backup method that lets you start the engine even if the key fob battery is dead. In practice, you bring the fob close to the Start/Stop button, press the brake, and start as you normally would. Some model years also offer a hidden key slot or pocket location for emergency starts, so check your owner’s manual for the exact location.

Backup start methods for MDX

Use these steps to start the MDX when the fob is dead.

1. Ensure the fob is inside the vehicle, within close proximity to the Start/Stop button.


2. With the brake pedal pressed, press the Start/Stop button once. The system should recognize the fob and start the engine.


3. If the engine does not start on the first attempt, reposition the fob closer to the Start/Stop button and try again.


4. Continue attempting for a short period. If repeated tries fail, stop and seek assistance from Acura Roadside Assistance or a dealer.


5. Once the engine is running, plan to replace the key fob battery promptly to avoid future issues.

In some MDX trims, there may be a designated area or slot for emergency starts when the fob battery is dead. If you can’t locate it, refer to the owner’s manual for your specific year and model.

Emergency alternatives and troubleshooting

If the standard backup method doesn’t work, consider these additional steps and checks. This information helps you diagnose common issues without compromising safety.

• Inspect and replace the key fob battery. Most Acura fobs use a CR2032 battery; confirm the exact specification in your manual and replace if needed.


• If you have a spare key fob, try starting with it to determine whether the issue is limited to the primary fob.


• Verify that you are attempting to start from inside the vehicle with the brake pedal depressed, as starting procedures can vary by year and trim.


• Check for signs of immobilizer or security system faults. A persistent failure to start may indicate a larger system issue that requires dealer diagnostics.


• Consult the owner’s manual for the precise emergency-start location if your MDX has a dedicated fob slot or pocket, as this can vary by model year.

Bottom line: keep a spare battery on hand and arrange a quick replacement to restore normal starting capability.

Summary

Facing a dead key fob on an Acura MDX doesn’t necessarily leave you stranded. Use the built-in backup method—bring the fob close to the Start/Stop button, hold the brake, and press Start. If that fails, try a spare fob or replace the fob battery, and consult a dealer if identical issues recur. Regular maintenance of the fob battery helps prevent future interruptions and keeps your MDX ready to roll.

Is there a key hole behind the push to start button?

Unless you broke everything up, then no. If you have push button start, there is no physical ignition anywhere on your car that you can insert a key to start it.

Will Acura work with a low battery fob?

Even if the key fob battery is entirely dead, you can still start the vehicle by bringing the fob close to the start button. I recommend going to AutoZone to get a CR2032 battery. It's inexpensive and easy to replace yourself. They can even help you with the installation if needed.

How to start mdx with dead fob?

To start an Acura MDX with a dead key fob, hold the key fob directly against the push-button start, press the brake pedal, and then push the start button. The car can still be opened using the physical key located inside the fob, accessible by sliding a release lever.
 
This video demonstrates how to open and start an Acura with a dead key fob: 1mSerra AcuraYouTube · Sep 13, 2021
Step 1: Open the door

• Look for a small release on the key fob to slide and remove the physical, mechanical key.
• Use this key to unlock the driver's door, as the remote's electronic lock function will not work. 

This video shows how to get inside an Acura MDX with a dead key fob: 1:00PYR Automotive YouTube · Jan 30, 2023
Step 2: Start the engine 

• Get into the car, press the brake pedal, and take the key fob. 
• Press the part of the fob that contains the transponder chip directly against the engine start/stop button. For most Acura models, this is the back of the fob. 
• The car's sensor will detect the fob's chip, you may hear a beep, and the start button may change color, indicating it's ready. 
• Press the start/stop button to start the car as you normally would. 

This video demonstrates how to start an Acura MDX with a dead key fob: 0:50PYR Automotive YouTube · Jan 17, 2023
Step 3: Replace the fob battery 

• The fob-battery backup method is a temporary solution. You should replace the dead battery as soon as possible to avoid being locked out again. 
• The MDX fob typically uses a CR2032 battery. 

Will my car start with just the key without a fob?

Yes, you can often start your car without the key fob, especially if it's just the battery that's dead, by placing the fob directly on or near the push-button start. If you have lost the fob entirely, you will not be able to start the car with a push-button start unless you have a mechanical key, a digital key card, or a professional can help. 
If the key fob battery is dead

• Use the backup system: Most cars have a backup system that detects a dead fob. Place the fob directly against the start/stop button or the steering column to start the car, as a direct proximity can still transmit the signal. 
• Use the physical key: Many fobs contain a physical key inside. You can take this out to unlock the door and then use it in the ignition to start the car, as shown in this video. 

This video shows how to find and use the physical key hidden inside a key fob: 58sKPTV FOX 12 | Local news, weather Portland, OregonYouTube · Jan 8, 2025
If you've lost the key fob

• You cannot start the car: Without any key fob or the physical key it contains, you will not be able to start the engine if it has a keyless start system. 
• Your options include:
  • Using the physical key: If you have the physical key that the fob hides, you can use it to start the car. 
  • Using a digital key card: Some cars come with a digital key card that can start the car if placed in a specific slot, such as a wireless charging pad. 
  • Contacting a professional: You may need to contact a dealership or an automotive locksmith to get a replacement key or have the car reprogrammed, but this is often expensive.