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AI Box Fix

Power & connectionReviewed

"Device Not Supported" After Enabling ADB: Turn ADB Off

Car says device not supported after ADB code 142618? Enter the code again or reset the flag over ADB to restore car mode. Carlinkit TBox Ultra, Plus.

Quick answer

Turn ADB mode off again: connect the box to your computer, open its screen with scrcpy, and enter 142618 in Settings → Other → Factory settings until the message no longer says adb, then unplug and connect to the car. That restored car mode for two of the three owners who reported back, and it is the way back the community's ADB guide gives; the setprop command below worked for two more owners, and a factory reset revived one box.

Symptoms

  • After an ADB session (removing the exclamation mark, multitouch, app control) the car shows "device not supported" or "not compatible"
  • The box powers up and its LED is lit, but the head unit no longer shows CarPlay or Android Auto
  • The computer still sees the box over ADB or scrcpy, the car does not
  • You entered 142618 again and the box rebooted, but the car still rejects it
  • Neither the car nor the computer sees the box any more

Applies to

Connection to the car
CarPlay and Android Auto
Highest risk on this page
Advanced
Status
Workaround confirmed by the community

Why it happens

The box’s USB port has two personalities. In car mode it presents itself to the head unit as a CarPlay or Android Auto phone. Code 142618 in the factory settings switches the port into ADB mode, where it presents itself as an Android device for debugging, so a computer can control it. The car sees that unfamiliar device and reports it as unsupported.

The code is a toggle. Entering it once turns ADB mode on; entering it again without a reboot in between turns it off. The setting is stored in a system property, persist.sdcarplay.reverse.disable, which must read 0 for car mode. Every guide that uses ADB, including the ones for the exclamation mark on the Wi-Fi icon and multitouch, ends with switching back. When that last step is skipped, mistyped or does not stick, the box stays in ADB mode and the car refuses it.

Fixes, ranked

Enter 142618 again until ADB mode is off

  • Advanced
  • Time: 10 minutes
  • Worked for 2 of 3 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. Connect the box to your computer with a USB data cable and open its screen with scrcpy, as in enable ADB on an AI box. In ADB mode this is the only way to see the screen.
  2. Open Settings → Other → Factory settings and enter 142618.
  3. Read the short message that appears. If it contains adb, ADB mode has been turned on: enter the code once more.
  4. When the message appears without the word adb, unplug the box from the computer. One owner found the change took effect only after unplugging.
  5. Connect the box to the car. If it comes up in the wrong protocol, switch it as described in switch the box’s protocol.
Code entry under Settings → Other → Factory settings, seen through scrcpy. Reconstructed screen, labels may differ by firmware.

The community’s ADB guide gives this as the way back, and two owners confirmed it worked for them. An Ultra 2 owner whose box would not start in the car after the multitouch procedure entered the code and everything worked. An Ultra owner on the September 2026 firmware entered it once, saw the box reboot without any message, and still got “device not supported”; it came back on the fifth attempt.

On one Ultra 4 with August 2026 firmware the box rebooted every time the code was entered and came back in ADB mode, and the command in the next fix did not help either. If that is your box, go to the reset.

Set the car-mode flag back to 0 over ADB

  • Advanced
  • Time: 10 minutes
  • Worked for 2 of 3 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. With the box connected to the computer, check that ADB sees it:
adb devices
  1. Set the flag back to car mode. The last character is the digit zero, not the letter O:
adb shell setprop persist.sdcarplay.reverse.disable 0
  1. Check the value; it should print 0:
adb shell getprop persist.sdcarplay.reverse.disable
  1. Unplug the box from the computer and connect it to the car.

An Ultra owner whose box would not start after a multitouch session ran the command and the box connected again in Android Auto. Another Ultra owner thought the command had failed because ADB still worked, until they unplugged the box from the computer; after that ADB was off and the box was back in car mode.

The Ultra 4 owner from the previous fix read back 0 and the box still booted into ADB. A reply suggested turning off Developer options, which resets everything set there; nobody reported whether it helped. Before you give up on this fix, check you typed a zero: the letter O is a common slip when copying the command from a phone. The ADB cheat sheet lists the other commands these guides use.

Factory reset with the reset file on a microSD card

  • Advanced
  • Time: 30–60 minutes including setup
  • Worked for 1 of 1 report

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. Ask Carlinkit support for the factory-reset file for your model. This site does not host or link it.
  2. Format a microSD card of 32 GB or less as FAT32 and copy the file to its root.
  3. Insert the card into the running box and wait for it to reboot. The LEDs show when it restarts.
  4. Remove the card, connect the box to the car, and set it up again.

A TBox Plus owner turned ADB on in the car, could not connect with scrcpy, ran the disable command, and was then left with a box that neither the car nor any computer would see. The reset file brought it back. A forum regular also noted that some owners could only recover with a reset. Everything on the box is erased, so it is the last step before full recovery.

Things to try (unverified)

  • Check the memory card. A TBox Plus owner found a protocol file left on the card seemed to return the box to normal mode after an ADB session. They did not report back after checking in the car.
  • Turn off Developer options. Suggested for the Ultra 4 that kept booting into ADB; no result reported.
  • Do not reboot from inside ADB. One owner who finished a multitouch change with a reboot command had a box that stopped starting until the flag was set back to 0. Switch back to car mode first, then power-cycle.

If nothing works

If neither the car nor the computer sees the box, the problem is no longer ADB mode. One Ultra 2 owner reported exactly that straight after entering 142618, and boxes in that state need the manufacturer’s recovery procedure; see TBox Ultra recovery and read its risks first. For a box that still boots, a local reinstall of the official firmware is gentler; see update TBox firmware with FOTA.

When you contact Carlinkit support, give the model and firmware date, which guide you followed, which commands you ran in what order, the output of adb shell getprop persist.sdcarplay.reverse.disable, and what the car shows. The engineering codes page explains what each code changes. If the box was second-hand and has been modified by someone else, start here helps you decide whether replacing it is the better answer.

Parts the fixes above need

  • microSD card (32 GB or smaller, formatted FAT32)

    Local firmware updates, reset files and protocol-switch files are read from a FAT32 card.

Related fixes

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Changelog

  • Last reviewed against new community reports:
  • Confirmed by 5 community reports on Carlinkit TBox Ultra 2, Carlinkit TBox Plus.
  • 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.