Toyota 4Runner, Tundra, and Tacoma (1996-present): Why is My Key Fob Not Working?

Did you know some key fob problems can be fixed on your own at home? Keep reading to learn how to carry out these helpful fixes.

By Charlie Gaston - January 27, 2016

This article applies to the Toyota 4Runner, Tacoma, and Tundra (1996-present).

If the key fob to your Toyota 4Runner, Tacoma, or Tundra doesn't work the way it used to or appears to be completely non-functional, don't head down to your local Toyota dealership just yet. There are simple solutions you can do right there from your very own home, without ever needing to enlist (or pay for) the help of a professional mechanic or dealer, to fix the problem. Not all fixes can be done from home, but we've outlined the ones that can. We also explain when's a good time to make that trip to the dealership, after all.

Why isn't my key fob working infographic

Materials Needed

  • Replacement batteries
  • Microfiber cloth

Step 1 – Check the batteries

They might be going bad.

Before carrying out more complex troubleshooting tips, which we will explain how to do in subsequent steps, it's best to check the fob batteries for power. If they are going bad, you'll need to remove the old set and replace them with a new one.

  • Replacement batteries will typically cost between $2 and $5 for a set of two.
  • You can purchase individual and bulk sets at any local auto parts store or big box retailer.
  • Ensure your new batteries have a strong contact point; increased tension will improve performance.
  • Place the cover back onto your key fob and check the device for activity.
Key fob
Figure 1. Check the fob batteries.

Pro Tip

  • It's also a good idea to check your fuses (see your fuse box) at this point, as well.

Step 2 – Check the receiver

It might be shorting from seasonal moisture found in the air.

The receiver is located in the lift gate of your truck and can short if it's exposed to moisture. You'll need to pull the cover off the hatch to check the receiver for water (or moisture) damage.

  • Try drying the receiver with a dry microfiber cloth and creating tension along the contact point inside the actual key fob before seeking outside professional assistance.
  • Check your key for for results.
  • If you need to head down to the dealer, an electrical diagnostic report will run you around $85 and, if a replacement receiver is needed, you'll be looking at another $380 plus the cost of labor.

Pro Tip

  • Check the box (ECU) under the driver's seat for damage, as well. Moisture can become trapped here and will need to be repaired if the damage is significant.

Figure 2. Check the ECU.

Step 3 – Have a mechanic check the door lock actuator or latch assembly

It might be malfunctioning or going bad.

If your doors unlock but won't lock with the key fob, a bad door lock actuator or latch assembly could be the culprit.

  • However, if the doors unlock using the door control panel, then the issue is something else and will need further troubleshooting.
  • If there is a beeping sound, the issue could be related to your alarm.
  • If your alarm is malfunctioning, tricking itself into responding to the threat that you are about to lock your key fob inside your vehicle, then you'll need to see a professional mechanic for more advanced service repair (unless you are skilled in repairing sensors).
Rear door latch
Figure 3. Faulty rear door latch.

Step 4 – Reprogram the key fob

The factory programming might have been erased.

Occasionally, a key fob can lose its original programming and will need to be reprogrammed, which either you or a Toyota dealer can do.

  • Remove your key from the ignition, if it is not already.
  • Next, open ONLY the driver's side door (keeping it unlocked).
  • Insert the key into the ignition without turning it, and then remove it.
  • Using the door control switches, lock and unlock your doors (proceed for five passes) and do this within 40 seconds.
  • Close and then open the driver's side door, manually.
  • Within 40 seconds, lock and unlock your truck for five passes or cycles.
  • Turn the key on and then off in the ignition (once) to reprogram your key fob.
  • Remove your key from the ignition.
  • Your power doors will automatically lock within three seconds.
  • You will have 40 seconds to press and hold the "lock" and "unlock" buttons on your key fob. This should be done simultaneously and for one second.
  • Release both buttons, and hold the "lock" button for two seconds.
  • Wait three seconds, and programming is complete.

Key fob
Figure 4. The fob may need to be reprogrammed.

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