These instructions apply to the SsangYong Rexton Mk3 (Y400) 2017-2022.
For other models, please choose your vehicle here.
When the big centre screen in your SsangYong Rexton (Y400, 2017–2022) locks up — the navigation freezes mid-route, the touch surface stops registering, or the unit hangs on the boot logo — a forced restart almost always fixes it in under a minute. The Y400 runs the SsangYong MTXW100Y40 multimedia head unit (the same family fitted to the Musso pickup), an 8″ or 9.2″ touchscreen with TomTom navigation. Like any embedded computer it can stall, and the cure is a knob-hold reboot rather than a workshop visit.
What you are working with
The first-trim Rexton came with an 8″ screen; the EX/Ultimate and later cars use the 9.2″ unit with built-in TomTom maps. Both are full touchscreens and both keep one mechanical control: the Power/Volume rotary knob set into the bottom corner of the bezel. That knob doubles as the reset control. A long hold cuts power to the unit’s processor and forces a clean restart — the standard recovery for a frozen MTXW100Y40 head unit.
Soft reset — hold the Power/Volume knob
- Stop the vehicle, apply the handbrake and leave the ignition in ACC or ON so the screen stays powered.
- Locate the round Power/Volume knob on the corner of the touchscreen panel.
- Press and hold it — keep pressing well past the point where the sound mutes, about 10 seconds.
- The display blanks and the SsangYong logo reappears. Let go of the knob.
- Give it 20–40 seconds to reload audio, Bluetooth and the TomTom map engine. You are done.
Will a reboot wipe my settings?
No. The knob-hold restart only clears the unit’s temporary working memory. Paired phones, radio presets, saved navigation destinations, TomTom map data, brightness and language all sit in permanent storage and are untouched. It is the equivalent of restarting a phone, not resetting it — safe to repeat as often as needed.
If it stays frozen
- Full ignition cycle. Turn the Rexton off, open the driver’s door, wait two minutes for the head unit to power down with the CAN bus, then restart. A quick off/on is sometimes not enough.
- Pull the AV/audio fuse. With the ignition off, open the cabin fuse box (driver-side lower dash or passenger footwell) and remove the head-unit / AUDIO fuse for 30 seconds, then refit. This forces a hard power-down when the knob is unresponsive.
- Check the map SD card. On TomTom cars a loose or corrupt navigation SD card can hang the unit on boot. Re-seat it; if the freeze only happens in navigation, the card may need re-imaging by a dealer.
- Disconnect the battery. As a last resort, disconnect the negative terminal for two to three minutes to reboot every module. Reset the clock afterwards.
Factory reset (erases data)
Reserve this for a unit that misbehaves after every reboot, or for selling the car. With the system on, go to Settings → General/System and choose Factory data reset (sometimes Default). Confirm to wipe paired devices, presets, saved destinations and accounts back to factory state. Always try the knob-hold soft reset first — it clears almost every freeze without deleting anything.
Frequently Asked Questions
Which button restarts the Rexton Y400 screen? The single round Power/Volume knob on the corner of the touchscreen. Press and hold it about 10 seconds until the SsangYong logo returns.
Will I lose my TomTom favourites or maps? No. A knob-hold reboot leaves saved destinations and the on-board map data intact — only working memory is cleared.
Is the Rexton head unit the same as the Musso’s? Yes. Both use the MTXW100Y40 family, so the reset procedure is identical across the SUV and the pickup.
The screen hangs in navigation specifically — why? That points to the map SD card. Re-seat it; a corrupt card can stall the boot or freeze the route, and a dealer can re-image it.
Do I need the engine running to reboot? No. The ignition only needs to be in ACC or ON so the head unit has power; the engine can stay off.
Chasing a warning light or fault code on your Rexton as well? Our sister site autodtcs.com decodes every OBD-II diagnostic trouble code and tells you how urgent it is.
Independent guide — not affiliated with SsangYong. Always follow your official service manual and safety precautions. Read our full disclaimer.