ND Miata Navigation SD Card
The 2016–2023 ND MX-5 (ND1 and ND2) runs the same Gen 6 Mazda Connect CMU as the rest of the supported lineup, so navigation lives on a removable, vehicle-locked SD card. Card encryption, VIN pairing, counterfeit spotting, and troubleshooting are the same across every Gen 6 car and are covered on the platform reference. This page covers what’s specific to the ND. The 2024+ ND3 uses a different head unit and a different card; see what changed for the ND3.
The card is BHP1-66-EZ1N in North America
Section titled “The card is BHP1-66-EZ1N in North America”Every 2016–2023 ND in the US and Canada takes the same card: Mazda part BHP1-66-EZ1N, a full-size SD card sold as a genuine accessory. It’s the same part across the Gen 6 family (CX-3, CX-5, CX-9, Mazda3, Mazda6), so a card listed for a CX-5 fits your Miata. The final letter is a revision that Mazda bumps as the preloaded maps age; any current revision works in any model year because Mazda Toolbox brings the maps up to date.
The part number encodes the region. European and other-market NDs use different part numbers carrying their own map databases, and a card from the wrong continent is rejected outright. Outside North America, order by VIN through a Mazda dealer rather than matching a forum part number.
One mechanical note from the factory navigation manual: never slide the card’s side switch to LOCK. A write-protected card can’t be read and navigation won’t start.
Where the slot is
Section titled “Where the slot is”The slot sits low on the center stack, in the same panel as the two USB ports and the aux jack, behind a small unlabeled cover. The cover blends into the trim and takes a fingernail or a taped-up flat screwdriver to pop open; it snaps back in place afterward. The slot itself is push-push spring loaded: press the card in to release it, and it pops out far enough to grab.
Cars delivered with navigation often left the factory with a plastic pull-tab blocking the card contacts, removed at dealer prep so the card doesn’t activate before delivery. If you buy a used ND and find a tab hanging out of the slot, the card was never activated.
Every trim has the slot; only Grand Touring got the card
Section titled “Every trim has the slot; only Grand Touring got the card”| Trim (North America) | Card from factory |
|---|---|
| Sport | No card; slot present, nav inactive |
| Club | No card from factory; often added by dealer or a prior owner |
| Grand Touring | Card included |
Navigation on the ND is the card, not a different head unit. The CMU and the slot are identical on a Sport and a Grand Touring; insert a valid card and the Navigation entry on the home screen comes alive. Before buying a card for a used Club or Sport, pop the cover and check the slot, because accessory cards were a common dealer add-on. The Fiat 124 Spider shares the same CMU and the same card behavior; see the 124 Spider page.
What works without the card
Section titled “What works without the card”The GPS receiver is on the CMU board, not the card, so pulling the card costs you only the built-in maps. Position fix, clock sync, and the compass keep working; routing, the map display, and POI search go dark. Most owners cover navigation with a phone instead. Factory CarPlay arrived on the 2019+ ND and retrofits to earlier cars; see CarPlay on the ND by year.
Used and cloned cards usually don’t work
Section titled “Used and cloned cards usually don’t work”The card pairs to the first vehicle it runs in, after roughly 100 km of driving. Mazda’s manual is blunt about it: the card is valid in one vehicle only, and a card that has lived in another car won’t navigate in yours unless a dealer re-codes it. That $50 “tested, working” card pulled from a wrecked CX-5 is the most common way ND owners burn money here.
Two safe paths exist. A sector-by-sector clone of your own card is a valid backup for the same car. And a new card from a dealer or parts.mazdausa.com pairs to your VIN on its own. Cards priced at $20–50 on Amazon or eBay are counterfeits more often than not; the failure modes are on the platform page.
Map updates go through Mazda Toolbox
Section titled “Map updates go through Mazda Toolbox”New cards include three years of free map updates through Mazda Toolbox, a free desktop app. Eject the card, put it in your computer, and Toolbox downloads the current region-locked database onto it; there is no over-the-air path and nothing touches the CMU. After the free window, updates are paid, roughly $85–140 per region. One catch from the Toolbox FAQ: the free years apply only if a different nav card was never used in the car, another reason to skip used cards.
The card slows wireless CarPlay and eats RAM
Section titled “The card slows wireless CarPlay and eats RAM”The nav card shares an internal data bus with the CMU’s Wi-Fi chip. Seated, it delays wireless CarPlay connection by 2–5 seconds, slows Wi-Fi startup by about 3 seconds, and ties up 27–65 MB of memory after boot, whether or not you ever open the maps. If you navigate by phone, pulling the card is a free performance gain; reinsert it any time and nav is back on the next boot with no re-pairing. The measurements are on nav SD performance.
Also pull the card before any firmware update. A flash with the card seated can corrupt it; the sequence is on the update procedure page.
ND1 vs ND2: no difference
Section titled “ND1 vs ND2: no difference”The 2019 ND2 update changed the engine and the steering column, not the infotainment. ND1 and ND2 use the same CMU, the same slot in the same panel, and the same card part number. The break is the 2024 ND3, which moved to a new 8.8-inch system outside the Gen 6 platform; its card is a different part and nothing on this page applies to it.
Related
Section titled “Related”- Navigation SD cards and map updates — full platform reference
- Nav SD performance — measured boot and CarPlay impact
- CarPlay on the ND by year — phone nav as the alternative
- Dealer visit guide — ordering a card by VIN
- ND MX-5 overview