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AI Box Fix

SIM, Wi-Fi & GPSReviewed

AI Box SIM Card Not Working: Data SIMs, Roaming, IMEI

SIM shows signal but no mobile data on your AI box? Turn on data roaming, then enter the APN by hand. Carlinkit TBox Ambient, Plus, Ultra; Ottocast.

Quick answer

Open the SIM settings on the box and turn on data roaming, even in your home country: alone or with other SIM settings, that brought mobile data back for five of the eight owners who reported trying it. If roaming is already on, enter your carrier's APN by hand; on a TBox Plus running Android 13, install the 4 Jul 2024 firmware.

Symptoms

  • The status bar shows 4G or LTE and signal bars, but no app has internet unless you share Wi-Fi from your phone
  • Calls or text messages reach the SIM, yet mobile data never connects
  • The same SIM works in a phone or a mobile router
  • Data worked for months, then stopped after an update or a carrier change
  • A cross or exclamation mark sits on the signal icon

Applies to

Connection to the car
CarPlay and Android Auto
Firmware in confirmed reports
Carlinkit TBox Plus: 2024-07-04
Highest risk on this page
Advanced
Status
Workaround confirmed by the community

Why it happens

An AI box uses its SIM like a mobile router: it needs a data session, not only a registration on the network. Two settings decide whether that session opens. The roaming switch matters because many SIMs, especially from virtual operators that rent another carrier’s masts, look like roaming to the modem even at home; with roaming off, the box registers, shows bars and then refuses to use data. The access point name (APN) tells the modem how to reach the carrier’s internet gateway, and the box does not always fill it in from the SIM the way a phone does.

The box also identifies itself to the network as a data device, not a phone. Most carriers do not mind, but some phone-only plans refuse data to such devices, and in some countries carriers only allow devices on their approved list. Finally, a few firmware builds broke the modem outright; on the TBox Plus with Android 13 the community traced this to one build range.

Fixes, ranked

Turn on data roaming in the SIM settings

  • Safe
  • Time: 2 minutes
  • Worked for 5 of 8 reports
  • Recommended in the community FAQ
  1. Open Settings → Network & internet (on some builds Wireless networks) → SIM card.
  2. Tap the gear icon next to the carrier’s name.
  3. Turn on Mobile data.
  4. Turn on Roaming (“connect to data services when roaming”).
  5. Turn Wi-Fi off and open a web page in the browser. Give the modem up to a minute.
SIM settings behind the gear icon next to the carrier name. Reconstructed screen, labels may differ by firmware.

Three owners fixed it with the roaming switch alone; one of them pointed out that the SIM had never left its home network. A TBox Ambient owner needed roaming on plus the network type set to LTE and the APN protocol set to IPv4/IPv6. Another Ambient owner, whose access point kept disappearing, found that roaming had been off all along.

Three owners already had roaming on and still had no data. One of them later found that data worked only on the first start after plugging in, which a firmware update fixed; that pattern is covered in no mobile data after sitting overnight.

Enter your carrier's APN by hand

  • Safe
  • Time: 10 minutes
  • Worked for 4 of 7 reports
  1. Look up your carrier’s APN settings on its website, or copy them from a phone that uses the same SIM: name, APN, and username and password if the carrier lists them.
  2. On the box: Settings → Network & internet → SIM card → gear → Access point names.
  3. Tap + and enter the values exactly as the carrier gives them.
  4. Tap ⋮ (top right) → Save, then select the new entry so its dot is filled.
  5. If data still does not start, open the entry again and set APN protocol to IPv4/IPv6, and set Preferred network type to LTE (or LTE/WCDMA).
  6. Restart the box and test with Wi-Fi off.

A TBox Plus owner whose access point list was empty got data the moment the APN was added and saved. An owner of an Ottocast Picasou 3 fixed the same symptom by typing in every field as it appeared on their phone. On a TBox Ambient that had worked for a year, the APN had vanished; restoring it together with the roaming switch brought data back.

Two owners already had the right APN, and for a third it worked until the next restart, when data dropped again although the entry was still there. If your APN disappears after every restart, see the unverified tips below.

TBox Plus on Android 13: install the 4 Jul 2024 firmware

  • Advanced
  • Time: 20–30 minutes
  • Worked for 2 of 2 reports
  • Recommended in the community FAQ

Warranty warning: this uses developer or engineering access. Follow the undo steps afterwards; some sellers refuse warranty claims on units with debugging left enabled.

  1. Open Settings → About and confirm the unit is a TBox Plus on Android 13; note whether it is the EM (668) or EAU (138) variant. Which TBox do I have explains the labels.
  2. Get the official 4 Jul 2024 build for your variant from Carlinkit’s support channel.
  3. Install it with FOTA Update → Local update, following update TBox firmware with FOTA.
  4. After the restart, check the SIM settings from the first two fixes again.

The community FAQ lists this build as the fix for Android 13 TBox Plus units on which no SIM card worked. Two owners confirmed it: one whose box saw the SIM but never connected, and one with a data SIM showing a cross and an exclamation mark although the IMEI was present. One helper reported that a later build from late November did not restore the SIM for them, with or without a reset.

Use a data-only SIM, and check the IMEI

  • Safe
  • Time: 5 minutes
  • Recommended in the community FAQ
  1. Test the SIM in a phone first. If it has no data there either, the problem is the plan or the account.
  2. If the SIM is a phone plan, ask the carrier whether it allows data in tablets, routers or other data devices. If not, use a data-only, tablet or IoT plan.
  3. Open Settings → About (on some builds Settings → More → About phone) and look at the IMEI.
  4. If the IMEI shows 0 or is blank, stop here and contact the manufacturer; no setting will make that modem connect.

The community FAQ treats a data-device plan as the starting point for any Carlinkit TBox. Ordinary phone SIMs work in many boxes: when one owner’s phone SIM did not work, others replied that theirs ran fine, and that it depends on the carrier. Some carriers keep a list of approved devices and block anything they do not recognise; US carriers are known for this. Changing a device’s IMEI is illegal in many countries and is not covered here.

Things to try (unverified)

  • Toggle airplane mode. Turning it on for a few seconds and off again forces the modem to re-register. It brought data back for owners whose box lost the network after starting, as described in no mobile data after sitting overnight, but nobody reported it fixing a SIM that never worked.
  • The APN disappears after every restart. One owner saved the APN, then opened Settings → Other → Factory settings → 4545 and tapped Save so the box restarted; it held for two days and then vanished again. Another owner on the same virtual operator found a new box kept the APN. Unresolved.
  • Check for a SIM PIN. A PIN lock can stop data. Suggested once; the owner did not report back.
  • Reseat the SIM. A thin SIM can lose contact in a tray without a spring. Suggested, not confirmed.
  • Remove the microSD card. One owner fighting a SIM problem and a microSD problem at the same time found mobile data started working once the card was out. The cause is unclear and it has not been reported again.
  • TBox Ambient with eSIM firmware. Some Ambient units run builds that support a cloud SIM. Owners on those builds were told to give the physical SIM priority; see no mobile data after sitting overnight. If the SIM disappeared after a 2026 update, read TBox Ambient loses the SIM after 2026 firmware.

If the box reboots as soon as the SIM is inserted, that is a power problem, not a SIM problem: see AI box keeps rebooting. An exclamation mark with data that otherwise works is a different issue, covered in exclamation mark on the Wi-Fi or signal icon.

If nothing works

Write down the box model and firmware date from Settings → About, the IMEI status (present, 0 or blank), the carrier and plan type, whether the SIM has data in a phone, and the exact icon in the status bar. A screenshot of the SIM settings and the APN entry saves a support engineer a round of questions.

Carlinkit lists its support contacts on its official FAQ page ([email protected]); Ottocast owners can write to [email protected]. If a known-good data SIM, the correct APN and roaming on still give no data, or the IMEI is blank or 0, the modem needs service and a warranty claim is the honest route. Sharing your phone’s hotspot works in the meantime; start here compares the box families if you are thinking of replacing the unit.

Parts the fixes above need

  • Data-only / IoT SIM card

    AI boxes use the SIM as a modem; a data-only plan avoids voice-plan device locks.

Related fixes

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Changelog

  • Last reviewed against new community reports:
  • Confirmed by 11 community reports on Carlinkit TBox Ambient, Carlinkit TBox Plus, Ottocast Picasou 3.
  • Page updated:

"Confirmed" means a community member reported that the fix worked on their unit. We have not tested it on our own hardware. How we verify.