What Is The Card Reader In Japanese Cars?

When it comes to the weird and wonderful world of JDM, there is one accessory/modification that is more authentically JDM than anything else.

Sure, you can go for yellow fog lights or a 180km/h dash cluster … but the real MVP of JDM car accessories looks a bit like this

That’s right, it’s one of those funny little card readers.

Familiar to many motorists who own ex-Japanese cars of all different makes and models, the card reader is a fairly ubiquitous piece of JDM automotive curios. 

Usually found by the driver’s knee area, but also sometimes in the glovebox or mounted to the dashboard, if you’ve owned or driven a used Japanese import car, then you’ve probably seen one of these in the past.

But what is the card reader in Japanese cars? And what exactly does it do?

In this edition of Car Facts we will explain it all for you!

What Exactly Is The Card Reader?

Long story short, the card reader/card “box” you sometimes find in Japanese cars is a reader system for ETC toll road payment.

The system is built on the 5.8ghz wireless band, and the on-board card reader can “talk” to the roadside toll collection system and vice versa.

The reader unit itself is only half of the puzzle. The other component that is required to make the system work is an ETC card, which is a bit like a credit/debit card but specifically for payment of road tolls (another way to think of it is like an Oyster card/public transport card). From what we can gather, some ETC cards are prepaid but most are postpaid like credit cards, and this means that it can be challenging for foreigners to get one without having the right bank account and documentation.

In Japan, a motorist has an ETC reader unit installed into their car. This unit carries information about the vehicle. The owner then inserts their ETC card into the unit before going through the toll gate.

Some cars built specifically for the Japanese domestic market actually have their own in-built card readers, but most of the time it is an aftermarket unit.

An advantage of this approach (as opposed to having an all-in-one unit that is both the reader and the payment card) is that more than one payment card can be used with any given vehicle. For example, person A might drive the car today and pay for a toll road with their card, and then person B might drive the car tomorrow and use their own ETC card.

What Is The ETC System?

ETC stands for ‘Electronic Toll Collection’, and is a way of expediting toll road fee collection and reducing congestion.

If you’ve ever used an old-fashioned cash toll road (or even one that allows for manual debit/credit card payment) then you’ll know it can be a slow and time-consuming process to pay your toll.

You have to stop and pay the toll booth attendant, or at the very least swipe your card through some kind of automated system.

However, with the Japanese ETC system all you need to do is approach an ETC lane (with a valid card and functioning reader), slow down to approximately 20 km/h and then the toll road gate will open and let you through. The appropriate fee for the road is then deducted from your card, and you are on your merry way with minimum fuss and inconvenience.

The following graphic does a good job of explaining how the ETC system works in Japan:

The ETC system helps to make toll road traffic flow more freely and smoothly.

Unlike many other countries, Japan has various roads that are owned and operated by different road companies (this is as opposed to a country like New Zealand, where we are based, where all roads are effectively owned and maintained by the government) and there can be different pricing for some roads compared to others. There are also factors like peak and off-peak pricing, holiday specials and other price factors. The ETC system handles all of this automatically!

Can You Use The Card Reader Outside Of Japan?

Almost certainly not.

While some other countries use similar types of systems, it’s unlikely that you’ll be able to take a card from a different country’s system and use it in the Japanese reader … the ETC system really is custom to Japan, at least in terms of the way it’s implemented in Japanese vehicles.

We therefore don’t really understand why the readers are typically not removed before vehicles are sold at auction and exported overseas to countries like New Zealand, Australia and the United Kingdom … surely there must be a market for second-hand readers? If you have any insight into this, please leave a comment below.

One thing to note (and you might have picked up on this already if your car has one of these readers) is that they will typically throw a warning message via the unit’s in-built speaker if there is no valid ETC card inserted. You can learn more here about this and why your car is talking to you in Japanese.

Recap – What Is The Card Reader In Japanese Cars?

The small card reader unit you find in many ex-Japan cars is an ETC (i.e. electronic toll road payment) card reader.

A driver inserts their valid ETC card, and the reader unit communicates with the toll gate to deduct the correct fare off the car and allow the vehicle access through the gate.

In our view, this is about as legitimate of a JDM piece of technology as it is possible to find, as the system was built specifically for Japan and only functions there.

You won’t find one in a made-for-export Japanese car; it’s purely technology for the domestic market.

We’ve read stories online of people looking to buy card readers for their JDM cars just to “look the part”. Although the reader is fundamentally useless outside of Japan, it is a cool little piece of kit nonetheless.


  • Sam

    Sam focuses mainly on researching and writing the growing database of Car Facts articles on Garage Dreams, as well as creating interesting list content. He is particularly enthusiastic about JDM cars, although has also owned numerous European vehicles in the past. Currently drives a 3rd generation Suzuki Swift Sport, and a Volkswagen Touareg (mainly kept for taking his border collie out to the hills to go walking)

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