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Key Fob Battery Replacement 1998 Toyota Supra

By CarCOX · Published 2026-05-20 · ~8 min read

Is your 1998 Toyota Supra key fob not working? Learn how to perform a simple key fob battery replacement yourself and restore its functionality quickly.

At a glance

Difficulty
6/10 — Easy to moderate
Est. repair cost
$80 – $900 (parts + typical shop labor)
OEM tooling
Standard OBD-II scanner and hand tools
Common symptoms
  • Key fob is unresponsive: Pressing buttons yields no reaction from the vehicle.
  • Reduced operating range: The fob only works when you are very close to the Supra.
  • Intermittent functionality: The fob works sometimes
  • but not consistently.
  • Doors do not lock or unlock remotely: The primary function of the key fob fails.

Experiencing issues with your 1998 Toyota Supra's key fob? A common and easily fixable problem is a dead or weak battery. When your key fob stops responding, or its range significantly diminishes, a simple battery replacement is often all it takes to restore full functionality. This guide will walk you through the process, helping you avoid unnecessary trips to the dealership and get your keyless entry working again.

What drivers notice on this 1998 Toyota Supra

Drivers of the 1998 Toyota Supra typically notice a gradual decline in their key fob's performance before it completely fails. The convenience of keyless entry and remote locking/unlocking is a feature many depend on, and its absence can be frustrating. You might find yourself having to press the buttons multiple times, or getting closer to the vehicle than usual for commands to register.

At a glance: difficulty, repair cost, and diagnostic workflow

  • Difficulty Rating: 6/10 — Easy to moderate
  • Common Symptoms: Key fob is unresponsive: Pressing buttons yields no reaction from the vehicle.; Reduced operating range: The fob only works when you are very close to the Supra.; Intermittent functionality: The fob works sometimes, but not consistently.; Doors do not lock or unlock remotely: The primary function of the key fob fails.
  • Estimated Repair Cost: $80–$900 (parts + typical shop labor)
  • OEM Tooling Required: Standard OBD-II scanner and hand tools

Diagnostic workflow:

  1. Confirm the symptom on your vehicle.
  2. Scan for stored or pending codes with an OBD-II tool.
  3. Inspect the most common causes in this guide (visual checks first).
  4. Run verification tests before replacing parts.
  5. Repair, clear codes, and verify on a test drive.

Symptoms and warning signs

Recognizing the early signs of a dying key fob battery can help you address the issue proactively. Here are the common symptoms:

  • Key fob is unresponsive: Pressing buttons yields no reaction from the vehicle.
  • Reduced operating range: The fob only works when you are very close to the Supra.
  • Intermittent functionality: The fob works sometimes, but not consistently.
  • Doors do not lock or unlock remotely: The primary function of the key fob fails.
  • Trunk release fails: The remote trunk button no longer opens the trunk.
  • Panic button doesn't activate: The alarm function is unresponsive.
  • LED indicator on fob doesn't light up: Many fobs have a small LED that illuminates when a button is pressed; if it's dim or off, the battery is likely low.

How to verify and confirm the issue

Before assuming a dead battery, it's wise to perform a few quick checks to confirm the issue. This helps rule out other problems, such as a faulty key fob or a vehicle-side receiver issue.

  • Test a spare key fob (if available): If you have a second key fob, test it. If the spare works perfectly, it strongly indicates the primary fob's battery is the problem.
  • Check the operating range: Stand close to your Supra (within a few feet) and try the fob. If it works up close but not from a distance, the battery is weak.
  • Visual inspection: Carefully inspect the key fob for any signs of physical damage, such as cracks, water exposure, or corrosion around the buttons. Sometimes damage can mimic a dead battery.
  • Try a new battery: The most definitive test is to simply replace the battery with a fresh one. This is often the quickest and most cost-effective diagnostic step.

Common causes (most likely first)

For a 1998 Toyota Supra key fob, the causes for malfunction are typically straightforward:

  • Dead or weak battery: This is by far the most common reason. Batteries have a finite lifespan and naturally deplete over time.
  • Physical damage: Dropping the key fob or exposing it to impact can damage internal components or dislodge the battery.
  • Water exposure: Moisture can short-circuit the internal electronics, leading to permanent damage.
  • Corrosion: Battery leakage or moisture can cause corrosion on the battery terminals or circuit board.
  • Worn out buttons: Over time, the internal contacts under the buttons can wear out, preventing a signal from being sent.

Step-by-step diagnosis and fixes

Replacing the battery in your 1998 Toyota Supra key fob is a simple DIY task. Here's how to do it:

  1. Obtain the correct battery: Most 1998 Toyota Supra key fobs use a CR1616 coin cell battery. However, it's always best to open your fob first and confirm the battery type and number printed on it before purchasing a replacement. You can find replacement batteries at most electronics stores or online.
  2. Open the key fob casing: Look for a small notch or seam along the edge of the fob. Use a small flat-head screwdriver or a coin to carefully pry open the two halves of the casing. Be gentle to avoid damaging the plastic.
  3. Remove the old battery: Once open, locate the small coin cell battery. Note its orientation (which side is facing up). Gently pry out the old battery using a small screwdriver or your fingernail.
  4. Insert the new battery: Place the new CR1616 battery into the slot, ensuring the positive (+) side faces the same direction as the old battery (usually upward).
  5. Close the key fob: Carefully align the two halves of the key fob casing and press them together until they snap securely into place.
  6. Test the key fob: Stand near your 1998 Toyota Supra and test all the buttons (lock, unlock, trunk, panic). The fob should now respond instantly and from a normal operating range. If you're looking for other repair guides for your vehicle, check out our collection of All repair guides.

Repair options and cost factors

  • DIY battery replacement: This is the most cost-effective option, typically costing only a few dollars for the battery itself. The process usually takes less than 10 minutes.
  • Professional battery replacement: Some automotive service centers or dealerships will replace the battery for you. This will incur a labor charge in addition to the battery cost, making it more expensive than DIY.
  • Key fob repair/replacement: If a new battery doesn't resolve the issue, or if the fob is physically damaged, you may need to repair or replace the entire unit. A new OEM key fob can be significantly more expensive, often requiring programming to your vehicle, which adds to the cost. For more information on your vehicle, you can Browse vehicles on our site.

When to see a professional

While key fob battery replacement is a straightforward task, there are instances when professional assistance is recommended:

  • Battery replacement doesn't work: If you've replaced the battery correctly and the key fob still doesn't function, there might be internal damage to the fob's electronics or an issue with the vehicle's receiver.
  • Physical damage: If the key fob has been severely damaged by impact or water, it might be beyond a simple battery swap.
  • Reprogramming issues: Although rare for just a battery change, some fobs may lose their programming. If your fob needs to be reprogrammed to the vehicle, a professional with diagnostic tools will be required.

Frequently asked questions

How long does a 1998 Toyota Supra key fob battery last?

Typically, a key fob battery in a 1998 Toyota Supra can last anywhere from 2 to 5 years, depending on usage frequency and environmental factors. You might notice a gradual decrease in performance before it completely dies, indicating it's time for a replacement.

Do I need to reprogram my 1998 Toyota Supra key fob after changing the battery?

In most cases, no. Changing the battery in a 1998 Toyota Supra key fob does not usually require reprogramming the fob to the vehicle. The fob's internal memory retains its programming even when the battery is removed, making it a simple swap-and-go process.

What type of battery does a 1998 Toyota Supra key fob use?

The 1998 Toyota Supra key fob commonly uses a CR1616 coin cell battery. However, it's always best practice to open your specific key fob and verify the battery type printed on the old battery before purchasing a replacement to ensure compatibility.

Helpful links

On ClearTheCode

Sources and further reading

For additional vehicle-specific information, always consult your 1998 Toyota Supra's owner's manual. Online forums and dedicated Toyota Supra communities can also offer valuable insights and tips from other owners.

Disclaimer: This article provides general information and is not a substitute for OEM service procedures. Always use a qualified technician for safety-critical work.

Cited catalog sources

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