Reference / reviewed
AI Box Engineering Codes: 4545, 166888, 121212, 142618 and More
Every factory-settings code owners use on Carlinkit TBox, Ownice and Ottocast AI boxes: what each opens, what you can change, risk and how to undo it.
Engineering codes open hidden settings screens on Android AI boxes. On Carlinkit units you type them into Settings → Other → Factory settings; Ownice uses the same screen with its own code, and Ottocast hides its version under a “Boot menu”. This page lists every code that owners in the community have used, what it opens, what you can change there, and how to put things back.
The codes at a glance
| Code | Where you type it | What it opens | Devices | What you can change | Risk |
|---|---|---|---|---|---|
| 4545 | Settings → Other → Factory settings | Main engineering menu (“Other” tab) | Carlinkit TBox Plus, Ambient, UHD, Ultra 1–4 | Side navigation bar, start-up delay, CarPlay / Android Auto protocol, car’s own GPS, CPU temperature overlay | Advanced |
| 166888 | Settings → Other → Factory settings | Audio engineering menu | TBox Plus, Ambient, UHD; Ultra with caution | “Force Audio 44K” (forced 44.1 kHz output), then Save and reboot | Advanced |
| 110144 | Settings → Other → Factory settings | Clears the system cache, no menu | TBox Plus, Ambient, Ultra 1–4 | Nothing to set; apps and settings stay | Advanced |
| 121212 | Settings → Other → Factory settings | Split-screen preset builder | TBox Ambient, Ultra 1–4, TBox Plus on later Android 13 builds | Split ratio and the two apps; saves a dual-app shortcut | Advanced |
| 142618 | Settings → Other → Factory settings | Toggles USB “ADB mode” | TBox Ultra 1–4; also used on Plus, Ambient, UHD | Box stops acting as a CarPlay / Android Auto device and appears to a computer as an ADB device | Advanced |
| 9999 | Settings → Other → Factory settings | Developer options | TBox Plus, Ownice; not on Ultra firmware from late 2025 | Standard Android developer options (DPI, USB and Wi-Fi debugging) | Advanced |
| 1260 | Settings → Factory settings | Ownice engineering menu, second tab | Ownice A5 / A5 HD | Side system panel (navigation bar) on or off | Advanced |
| adbdev | Settings → Special settings → Boot menu | Turns on developer options until the next reboot | Ottocast Picasou 2 / Picasou 2 Pro, some Picasou 3 firmware | Developer options, including Minimum width (DPI) | Advanced |
| 126 | Settings → Special settings → Boot menu | Ottocast hidden factory menu | Ottocast Picasou 2, 2 Pro, Picasou 3 | LTE options, boot logo, calls through the SIM, USB debugging | Advanced |
| 88888888 | Your phone’s Wi-Fi settings | Default password of the box’s own hotspot | Ottocast Picasou 3, OttoAibox Nano | Lets a phone join the box’s hotspot to enable ADB on port 65535 | Advanced |
| *#*#4636#*#* | A phone (dialer) app on the box | Android’s built-in testing menu | Any box with a dialer app, used on ApplePie UX999 | Preferred network type (for example LTE only) | Advanced |
Every code is rated Advanced because each one changes settings outside the normal Android menus, and one of them (166888) has left a box stuck in a reboot loop. Before you change anything, note the current value so you can set it back, and keep the undo steps in each section open. The sections below explain each one, in the order owners ask about them.
4545: what is in the Carlinkit engineering menu?
4545 is the code Carlinkit’s own help pages use, so it is the one with the most official documentation. After the code, open the Other tab. The items owners use most:
- System navigation bar: turns the left-hand dock off. You need this off before a third-party launcher works without an endless “Loading phone” screen. On recent firmware the same switch also sits in Settings → Display. See remove the navigation bar and floating button.
- Delay start connection: makes the box wait before it announces itself to the car. Carlinkit recommends 20 seconds when the box has to be unplugged to be recognised, and owners of cars whose CAN bus goes to sleep use 20–30 seconds. Carlinkit says the option needs firmware from 10 Aug 2023 or later. Background: car doesn’t detect the AI box.
- Protocol switching: switches the box between CarPlay and Android Auto in software. If the button reads “Android Auto”, the box is in CarPlay now. Switch only to a protocol your car supports; if the car stops seeing the box, use the box’s physical mode button to come back. Full walk-through: switch between CarPlay and Android Auto.
- Use OEM GPS: takes position from the car instead of the box’s own receiver. It is off by default. Not every car sends GPS data, and owners found it usually works only in CarPlay mode; if your map stops moving, turn it off again.
- Show CPU temperature: puts a small temperature readout in the top-right corner. One owner showed the toggle and its readout in a video, and the community FAQ recommends it for judging heat; see how hot is too hot.
Two side effects were reported. One owner found that changing anything under 4545 reset the arrangement of home-screen icons, and another saw split-screen shortcuts made with 121212 disappear after visiting 4545 or switching protocol. Take a photo of your home screen first.
One TBox Ambient owner on 2026 firmware noticed that opening 4545 and rebooting made the SIM card work until the next restart. That is a symptom of a firmware regression, not a fix; see TBox Ambient SIM lost after 2026 firmware.
166888: does forcing 44.1 kHz improve the sound?
166888 opens the audio menu. Its main switch is Force Audio 44K: turn it on, tap Save, and wait for the box to reboot. Carlinkit’s own help page recommends it when music or video sound cuts out like a skipping disc, and the community FAQ says sound gets better for some owners on the TBox Plus, Ambient and UHD.
One owner’s box went into an endless reboot loop right after they turned Force Audio 44K on and tapped Save. A factory reset was not possible because the box never finished booting; another owner pointed them to the manufacturer’s recovery image, and after flashing it the box started normally again. Recovery images are available from the manufacturer’s support channel (Carlinkit: [email protected]); ask for the one that matches your exact model.
On the TBox Ultra the results are mixed. One owner heard more bass; others reported crackle, distortion that stayed after switching it off until a factory reset, and one had no sound at all until they disabled it. On an Ultra, try it only if your sound already has a problem, and undo it if nothing improves.
To undo it, enter 166888 again, turn Force Audio 44K off (or back to Auto), tap Save and let the box reboot. More detail: improve sound quality with 44.1 kHz and, if you hear crackle, crackling or muffled sound. One Ultra 2 owner noticed that a July 2026 build added Settings → Sound settings with noise suppression and audio/video sync sliders, so some of this may move out of the engineering menu.
110144: what does the cache code clear?
110144 clears the system cache. Owners describe it as a cache wipe only: apps, logins and settings stay after the reboot.
The community uses it as the first step when a box misbehaves after a firmware update, before a full reset; see factory reset after a firmware update. One owner whose backlight stopped adjusting after changing firmware without a reset fixed it by clearing the cache this way.
To undo it there is nothing to set back; the cache rebuilds itself as you use the box.
121212: how do I get real split screen on the stock launcher?
121212 opens a split-screen builder. Pick a ratio and an app for each side, and the box creates a dual-app shortcut on the home screen. TBox Plus firmware from 10 Oct 2023 added 3:7 and 2:3 ratios next to the default 1:1. One owner set up four presets this way and stopped using a third-party launcher altogether.
Known limits from owners:
- An app that is set as the stock launcher’s navigation widget cannot go into a split pair. Remove it from the widget first.
- The presets depend on Quickstep, the stock launcher component. Owners who uninstalled it could no longer save presets.
- Move the dual-app icon to another home-screen page; owners found it otherwise disappears over time.
- Some TBox Plus units do not accept the code at all.
More: split screen on Carlinkit.
142618: what is ADB mode, and how do I get out of it?
142618 switches the box’s USB port from “car mode” to “ADB mode”. In ADB mode the box no longer presents itself to the car as a CarPlay or Android Auto device; instead a computer sees it as an Android device you can send commands to. The screen shows “adb” between Chinese characters while the mode is on. In Android Auto you may see the car reconnect instantly, which means the switch happened.
Owners use it for the exclamation-mark icon fix and to disable the floating button. The full procedure is in enable ADB on an AI box and the commands in the ADB cheat sheet.
To return to car mode, use either:
- Settings → Other → Factory settings → 142618 again, then reconnect to the car.
- Or, while still connected by ADB:
adb shell setprop persist.sdcarplay.reverse.disable 0If you forget this step, the car says “device not supported”. One owner who hit that on September 2026 firmware is covered in device not supported after ADB; some owners needed a factory reset.
9999: why does the developer-options code not work on my Ultra?
On the TBox Plus and on Ownice boxes, 9999 opens Android’s developer options directly. On the TBox Ultra it stopped working on firmware from late 2025: owners on builds from November 2025 onwards report a black window that closes again, and several could not find a build number to tap either. On some third-party firmware the code is disabled and the build-number method still works. If neither works on your Ultra, the ADB route under 142618 does not go through developer options.
Ownice: 1260 and 9999
Ownice boxes use the same factory-settings screen with code 1260. The second tab holds the side system panel switch, the same job as 4545 → Other on Carlinkit. 9999 opens developer options on Ownice too.
Ottocast: adbdev, 126 and the hotspot password
Ottocast hides its menu differently. On the Picasou 2 and Picasou 2 Pro, open Settings → Special settings (near the bottom, “Additional settings” on some builds) → Boot menu, and enter adbdev as the password. Developer options then appear under Settings → System; they disappear after a reboot, but changes you made there are kept. Owners use this to change Minimum width (DPI) when the picture is too large for the car screen.
Code 126 in the same Boot menu opens Ottocast’s hidden factory menu, with LTE options, boot logo and, in the last tab, a switch for calls through the SIM card. It also holds a USB debugging switch: one owner warned that with USB ADB on, the box no longer connects to the car. Turn it back off from the same menu.
The Picasou 3 and OttoAibox Nano have no code for developer options. Instead you join the box’s own Wi-Fi hotspot from a phone (default password 88888888, or see the box’s hotspot settings), connect an ADB shell app to the hotspot’s gateway address on port 65535, and run the command in the ADB cheat sheet. One Picasou 3 Pro owner reported a different default hotspot password (12345678) and a different port, and said USB debugging is closed on that model. Change the hotspot password from the default once you are done.
Codes with thin or unclear evidence
These come up in threads, but nobody reported a clear, useful result. They are listed so you know what they are, not as recommendations.
| Code | Reported meaning | Why it is not in the main table |
|---|---|---|
| 9527 | ADB over Wi-Fi on the TBox Plus (port 5555); one owner reported it also works on an Ambient (SM6225) | Another owner got an “unauthorized” error until USB debugging was also on, and one forum regular advised leaving it alone; Wireless debugging in developer options does the same job |
| 888888 | Serial-port debugging on or off | No owner use for it |
| 188666 | Bluetooth call recording switch | One owner who turned it on got a box that connected but showed no picture |
| 6868 | Suggested for removing the activation QR code | The owner who tried it said it did not help; see device not activated / QR code |
| 7890 | Described as “reset settings” on the Ultra | One mention, no confirmation |
If you find a code that does something useful, or one of these has a clear effect on your unit, tell us with the bug and report guide and include your model and firmware date.
Android’s own testing menu: *#*#4636#*#*
This one is not a manufacturer code. Typing *#*#4636#*#* in a phone (dialer) app opens Android’s testing menu on most builds. Under phone information you can set the preferred network type, for example LTE only or LTE/WCDMA. ApplePie UX999 owners use it when the modem keeps dropping to 3G. Setting the type back to the previous value undoes it.