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2017-2020 Toyota 86 & Subaru BRZ Keyless Entry Module: Why Your Key Fob Stopped Working

A complete guide to diagnosing a failed keyless entry module, understanding replacement costs, and navigating the critical programming requirements.

6 minutes to read 2018-2020 SUBARU BRZ 2017-2020 TOYOTA 86
Difficulty
2/5
Est. Time
1.5 hrs
DIY Doable?
🔧 Shop
Shop Labor
$100 - $250
Used OEM Price
$70 - $100
⚠️ Drivable, but... — Yes, but only if the car still recognizes the key to start the engine. If the failure affects the immobilizer function, the car will not start, leaving you stranded.
Key Takeaways
  • A replacement Keyless Entry Module MUST be professionally programmed by a dealer or qualified locksmith; it is not a plug-and-play part.
  • Before blaming the module, always replace the key fob battery and check the main car battery, as these are more common failure points.
  • The module is located behind the glove box and is easy to physically replace, but the mandatory programming is what makes the job difficult and costly.
  • Buying a used OEM module with a matching part number (88801CA350) is a viable, cost-effective option, but you must factor in the cost of programming.
The Keyless Entry Module, also known as the Smart Main ECU, is the electronic brain for your vehicle's remote functions. It receives radio frequency signals from your key fob to lock and unlock the doors, open the trunk, and sound the panic alarm. Crucially, this module is also integrated with the car's immobilizer system. It verifies that a valid, programmed key is present before allowing the engine to start, making it a vital component for both convenience and security.

Symptoms of a Failing Keyless Entry Module

When the keyless entry module in a 2017-2020 Toyota 86 or 2018-2020 Subaru BRZ begins to fail, the symptoms can often be mistaken for a dead key fob battery or a weak car battery. It's important to rule out these simpler issues first before suspecting the module itself.

  • Intermittent or No Response from Key Fob: The most common symptom is the key fob ceasing to work. You may find yourself pressing the lock or unlock button multiple times with no effect, or it may work only sporadically.
  • Reduced Remote Range: You might have to stand very close to the vehicle for the key fob to register, whereas it used to work from a much greater distance.
  • All Key Fobs Fail: If you have a spare key fob and it also fails to communicate with the car (after checking its battery), it strongly points to a problem with the vehicle's receiver module rather than the fobs themselves.
  • Car Fails to Detect Key for Starting: For models with push-button start, the car may display a "Key Not Detected" message and refuse to start, even with the fob inside the vehicle. This happens because the module cannot validate the immobilizer code from the key.
  • Interior Lock Switches and Trunk Release May Also Fail: In some instances, a faulty module can cause the interior power lock/unlock switch and the interior trunk release button to stop working until the ignition is turned on.

Pro Tip: Before suspecting the module, always start by replacing the battery in your key fob (it's typically a CR1632 for these models). Also, check the health of your main car battery. A weak or dying car battery can cause a wide range of electronic issues, including poor keyless entry performance.

Buying a Used Keyless Entry Module

Given that a new OEM module can be very expensive, a used OEM part is a cost-effective and reliable alternative. Aftermarket modules for this specific component are generally not available, making used OEM the best budget-friendly choice. Here’s what to look for:

  • Match the Part Number Exactly: The most critical step is to match the OEM part number on your original module. For the 2017-2020 Toyota 86 and 2018-2020 Subaru BRZ, the primary part number is 88801CA350. The Denso manufacturer number is 232900-7080. Do not install a module with a different part number, even if it looks identical, as it may not be compatible.
  • Physical Inspection: When the part arrives, inspect the casing for any cracks or signs of water damage. Check the connector pins to ensure they are straight and free of corrosion.
  • Source from a Reputable Seller: Purchase from a seller that offers a warranty and a return policy. This protects you in case the part is dead on arrival.
  • Budget for Programming: A used module is a paperweight until it is professionally programmed. It will not work by simply plugging it in. Factor the cost of programming by a dealer or automotive locksmith into your total repair cost.

Warning: This module is a core part of the vehicle's anti-theft and immobilizer system. It must be professionally programmed to your vehicle and existing keys. This is not a DIY-friendly task.

Programming Requirements

Replacing the keyless entry module is not a simple plug-and-play repair. The new or used module must be electronically paired with your vehicle's systems and keys.

  • Professional Programming is Mandatory: There are no self-programming procedures for this module. You will need either a Toyota/Subaru dealership or a qualified automotive locksmith with advanced diagnostic tools (like an Autel IM508/IM608 or Subaru Select Monitor) to perform the programming.
  • Dealership vs. Locksmith: A dealership can always perform the programming, but they are typically the most expensive option. An automotive locksmith is often more affordable and can provide the same service. However, always call ahead to confirm they have the capability to program this specific module for your vehicle.
  • 'All Keys Lost' Scenario: If you lose all your keys, the situation becomes much more complex and expensive. The official dealer procedure may involve replacing not just the keyless entry module but also the immobilizer ECU and steering lock module, potentially costing thousands. This highlights the importance of having a spare key and addressing a faulty module before it leads to a bigger problem.

Replacement Overview and Difficulty

  • Installation Difficulty: 1/5 (Physical replacement is very easy)
  • Programming Difficulty: 5/5 (Requires expensive, specialized tools and expertise)

The physical installation of the module is straightforward. It is located behind the glove box. The process involves:

  1. Disconnecting the vehicle's battery.
  2. Opening and removing the glove box assembly to gain access.
  3. The module is typically mounted to a metal bracket with two 10mm bolts.
  4. Unplug the three electrical connectors from the bottom of the module.
  5. Remove the bolts and take out the old module.
  6. Install the replacement module and reconnect everything in reverse order.

After installation, the vehicle will not start and the remote will not work until the module is programmed.

Cost Comparison

Here is an estimated breakdown of costs to replace the keyless entry module. Prices can vary based on location and supplier.

ItemEstimated Cost
New OEM Module$500 - $750
Used OEM Module$70 - $100
Mail-In Repair Service$175 - $250
Shop Labor (Programming)$100 - $250

Known Issues, TSBs, and Recalls

As of mid-2024, there are no specific recalls or widespread Technical Service Bulletins (TSBs) from Toyota or Subaru directly addressing the failure of the keyless entry module for the 2017-2020 Toyota 86 or 2018-2020 Subaru BRZ. Most owner complaints are resolved by addressing battery issues or, in cases of module failure, by replacing and reprogramming the unit.

Frequently Asked Questions (FAQ)

Can I program a used keyless entry module myself?

No. This module requires special diagnostic equipment and software subscriptions that are only available to dealerships and professional automotive locksmiths. There is no DIY programming procedure for this part.

My key fob stopped working. Is it definitely the module?

Not necessarily. Always start with the cheapest and easiest fixes: replace the battery in the key fob, test your spare fob, and check the main car battery's health. Radio frequency interference can also cause temporary issues. If all of these are ruled out, then the module itself becomes the primary suspect.

Can I still drive my car with a bad keyless entry module?

Maybe. If the module fails in a way that it can no longer recognize the immobilizer chip in your key, the car will not start. If it only affects the remote lock/unlock functions but the car can still detect the key for starting, you can drive it. However, you may not be able to lock or unlock your car remotely, which is a security risk.

Why is a used OEM module better than a new aftermarket one?

For this specific part, there are no widely available new aftermarket modules. The choice is between new OEM, used OEM, or a mail-in repair service for your original unit. A used OEM module is often the most cost-effective solution, providing the same factory performance as a new part for a fraction of the price, as long as it is programmed correctly.

Technical Specifications

OEM Part Numbers: 88801CA350 232900-7080

Controls remote functions (lock, unlock, trunk) and immobilizer verification. Operates on 315 MHz frequency band in North America.

Wrenchy
Article researched & written by
Go-Parts' AI research assistant. Every article is backed by live web research, verified OEM data, and real technician knowledge — so you get accurate, up-to-date information you can trust.
Meet Wrenchy → Updated Jul 21, 2026

The information in this article is provided for general reference and educational purposes only. Vehicle specifications, procedures, and part compatibility can vary by production date, trim level, and region. Always consult your vehicle's factory service manual and verify part numbers before purchasing or performing repairs. Safety-critical components such as airbags, seat belts, and braking systems should be installed by a qualified professional.

Year Coverage
This article covers the Keyless Entry Module for:
  • TOYOTA 86: 2017201820192020
  • SUBARU BRZ: 201820192020
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