Toyota, Lexus & Subaru 4D/8A Key Copy Guide with AT100 & KM100

Car keys play a major role in vehicle security; not only do they help protect your property, but they also determine whether your car can start properly. If you want to make a spare key, key cloning is a simpler process than key programming—provided you have an original key.

So, how do you duplicate a car key? This guide will use the Autel key programming tools—the Autel KM100 and AT100 chips—to complete the entire key cloning process. It provides detailed explanations of the application scenarios, required tools, and specific steps to help you complete the entire process quickly.

When Do You Need to Copy a 4D/8A Key Chip?

A 4D/8A chip copy is mainly useful when an existing vehicle key is still available and working, but the owner needs an additional spare key. For supported Toyota, Lexus, and Subaru vehicles, technicians can use AT100 to identify and copy the applicable transponder chip to a compatible blank chip.

When You Need a Spare Key

If the original key works normally, copying the 4D/8A chip can be a practical way to create a duplicate key for a family member or as a backup.

When the Original Chip Can Be Read

The original key must generally be available and readable because it provides the transponder information needed for the copying process. Autel AT100 can be used to identify and copy supported 4D/8A chips.

Chip Copy vs. Key Programming

Chip copying and vehicle key programming are different procedures. After copying the chip, some vehicles may require additional key programming. In such cases, KM100 can be used for the applicable vehicle-side programming procedure.

If all keys are lost, chip copying may not be applicable because there is no original chip to use as the source. A separate all-keys-lost or key programming procedure may be required.

Toyota, Lexus & Subaru 4D/8A Key Compatibility

So, which types of keys with which chips can perform this operation? As we’ve made very clear in the article title, this guide focuses primarily on keys with 4D and 8A chips. Of course, other chip types can also be programmed using the Autel AT100, but this article primarily covers the 4D and 8A chip types.

Toyota 4D/8A Key Copy

• 4D Chip Series (Texas 4D / TIRIS DST): This is an extremely common type of chip used by Toyota, widely found in numerous vehicle models. It includes various sub-models, such as 4D-67 (ID67), 4D-68, 4D-60, 4D-63, 4D-70, 4D-80, 4D-83, and others. The ID4D mentioned in your screenshot belongs to this series.
• 8A Chip Series: Used in certain Toyota and Lexus models, this series also includes several subtypes, such as 8A (P4=00 00 A8 A8) and 8A (P4=91 00 AA AA), among others.

Lexus 4D/8A Key Copy

• 4D Chip Series: 4D-67 (ID67), 4D-68 (ID68), 4D (Texas Crypto)
• 8A Chip Series: ID8A, Some newer models or models with high security levels

Subaru 4D/8A Key Copy

• 4D-60 Chip (Subaru G-chip): This is one of the most widely used chips in Subaru vehicles. For example, the second-generation Forester (SG) from 2003 to 2008 used this chip. It is also used in Forester, Impreza, Legacy, and Outback models from 2013 onward.
• 4D-62 Chip: Another common type, widely used in 2008–2011 models of the Forester, Impreza, Legacy, and others.

Note:This is just a simple list of compatible vehicle models; actual compatibility depends on the tool's coverage. Additionally, if you don't know the chip type of your car key, you can use the Autel KM100 to read and verify it.

AT100 vs. Autel KM100: What Does Each Tool Do?

AT100 for 4D/8A Chip Copy

The Autel MaxiIM AT100 chip is a universal, programmable transponder superchip designed to replace a variety of automotive key chips. The Autel AT100 supports cloning 4D/8A-type chips, enabling automotive chip duplication and simplifying the process of adding new keys.

Autel KM100 for Key Programming

The Autel KM100, on the other hand, is a simple key programming tool that can not only read key information but also clone or program keys to add new ones. When used in conjunction with the AT100, the Autel KM100 enables 4D/8A key copying for Toyota, Lexus, and Subaru vehicles.

What You Need Before Starting

What Tools do You Need to Prepare?

• Autel KM100 Key Programming Tool
• Autel AT100 Transponder
• A Working Original Key
• Blank keys that fit
• Vehicle

Before You Start

• Confirm vehicle compatibility
• Confirm the original key can be read
• Prepare a AT100
• Ensure the tools have sufficient power
• Follow the applicable vehicle-specific procedure

Autel MaxiIM AT100 Chip

How to Copy Toyota, Lexus & Subaru 4D/8A Chips

Step 1: Read the Original Key Data

Select the “Reading/Cloning” option from the Autel KM100 menu to enter the operation interface, place the original key in the KM100's recognition area, tap “Reading” in the lower-left corner, and complete the data reading.

Step 2: Clone the Original Key

Keep the original key in the sensing area, then press the “Cloning” button located in the center at the bottom of the Autel KM100 to begin reading the original key's data. Once the reading is complete, remove the original key and place an AT100 transponder chip in the KM100's chip recognition area, then press “Next” to begin cloning the data to the chip.

Step 3: Test the transponder chip after completion

After cloning is complete, don’t rush to install the chip into the key just yet. First, test whether the chip can start the vehicle normally. Use the chip to press the start button and see if the vehicle starts as expected. If there are no issues, install the chip into the new key and test whether the other functions work properly.

AT100 & KM100 4D/8A Key Copy Tips

When working with 4D/8A transponder keys, the AT100 transponder chip can be used with supported key types and vehicle applications. It supports the following 4D and 8A series:

• 4D type: 34 / 94 / D4 / 98
• 8A type: 88 / 8A / A9 / AA / 39 / F3

When using the AT100 with the KM100, first identify the original key's transponder type and confirm that it falls within the supported series. Then follow the KM100's on-screen procedure for the specific vehicle application.

Key tips:

• Confirm the original key is a supported 4D or 8A type.
• Use AT100 as the replacement transponder chip for compatible applications.
• Check vehicle coverage in KM100 before starting the key-copy procedure.
• Keep the original key available during the process for identification and verification.
• Follow the KM100 prompts step by step and test the replacement key after completion.

Important: AT100 is the transponder chip itself, while KM100 is the key programming tool used to perform supported key-related operations.

Final Thoughts

When you want to create a spare car key to start your vehicle, if you have a working original key, cloning it using the AT100 transponder chip is much simpler than the complex process of key programming. This tutorial is specifically for cloning Toyota, Lexus, and Subaru 4D/8A key chips.

If your key uses a different type of chip, be sure to first confirm whether the AT100 and Autel KM100 support cloning the chip in your vehicle's key. If they do, you can follow the procedure above to clone the key and add a new one.

Frequently Asked Questions

What is 4D/8A chip copying?

4D/8A chip copying is the process of copying supported transponder chip data to a compatible blank chip. With AT100, the applicable supported series include:

• 4D type: 34/94/D4/98
• 8A type: 88/8A/A9/AA/39/F3

Which vehicles can use the AT100 for 4D/8A chip copying?

AT100 supports applicable 4D and 8A transponder chip applications. For this guide, the focus is on supported Toyota, Lexus, and Subaru applications. Always verify the specific vehicle and chip compatibility before starting.

What does AT100 do during the key-copying process?

AT100 is used for the applicable transponder chip functions, including identifying and copying supported 4D/8A chips. It works with a compatible blank chip to create the duplicated transponder.

Can I copy a 4D/8A chip if I still have the original key?

Yes, having a working and readable original key is the typical scenario for chip copying. The original chip provides the source information for the applicable copying procedure.

Can I use chip copying if all keys are lost?

Generally, conventional chip copying requires an original chip as the source. If all keys are lost, a different all-keys-lost or key programming procedure may be required.