Symptom
Driver assistance features unavailable
Adaptive cruise control, lane keeping, blind spot warning or automatic emergency braking have switched themselves off, usually with a message saying so.
The car itself is unaffected. Steering, brakes and engine are exactly as they were — what has stopped is everything that was watching the road on your behalf. Nothing has been taken away that the car did not add.
The risk is the habit rather than the fault. These systems become invisible when they work, and a driver who has learned that the car keeps its own distance has stopped checking. So the useful response is deliberate: go back to your own following distance for the rest of the journey, and expect nothing to intervene.
Three ordinary causes account for most of them, and all are worth mentioning to whoever looks at it. A dirty, iced or snow-covered sensor — the front of the car, behind the badge, and the windscreen in front of the mirror. Recent front-end work, including a windscreen replacement, bumper repair or a parking knock that left no visible damage, because these sensors are aimed to a fraction of a degree. And a software update applied to one module and not another, which makes two systems describe the same road differently.
Switching off deliberately is the designed behaviour when something is uncertain, so a system that has disabled itself is usually working correctly. A system that stays on while aiming at the wrong part of the road is the failure that matters, which is why calibration after any disturbance is not optional.
Also described as: adaptive cruise not working, lane assist not working, cruise control unavailable, driver assist disabled, emergency braking unavailable, blind spot warning not working, سیستمهای کمک راننده غیرفعال, asistentes no disponibles, ayudas conduccion no disponibles, adas no disponible, أنظمة المساعدة غير متاحة, مساعدات القيادة معطلة, خصائص الأمان لا تعمل
What this usually means
The car itself is unaffected. Steering, brakes and engine are exactly as they were — what has stopped is everything that was watching the road on your behalf. Nothing has been taken away that the car did not add.
The risk is the habit rather than the fault. These systems become invisible when they work, and a driver who has learned that the car keeps its own distance has stopped checking. So the useful response is deliberate: go back to your own following distance for the rest of the journey, and expect nothing to intervene.
Three ordinary causes account for most of them, and all are worth mentioning to whoever looks at it.
- A dirty, iced or snow-covered sensor — the front of the car, behind the badge, and the windscreen in front of the mirror.
- Recent front-end work, including a windscreen replacement, bumper repair or a parking knock that left no visible damage, because these sensors are aimed to a fraction of a degree.
- A software update applied to one module and not another, which makes two systems describe the same road differently.
Switching off deliberately is the designed behaviour when something is uncertain, so a system that has disabled itself is usually working correctly. A system that stays on while aiming at the wrong part of the road is the failure that matters, which is why calibration after any disturbance is not optional.
And check the settings. Several vehicles allow assistance features to be switched off individually in a menu, and a car handed over with them disabled reports exactly this.
Working through it
| What you find | Likely cause | How to confirm it | What fixes it |
|---|---|---|---|
| Several functions unavailable at once | One shared sensor — they usually look through the same camera or radar | List what has gone. A single fault removing several functions is the norm rather than a coincidence. | Repair the shared sensor rather than each function. |
| Sensor area dirty, iced or snow-covered | Blinding — the correct response is to report unavailable | Clean behind the badge and the screen in front of the mirror, then retest. | No repair. Largest single share of these complaints. |
| Since front-end work, a windscreen, or a knock with no visible mark | Alignment — aimed to a fraction of a degree | Ask what happened rather than inspecting for damage. | Recalibrate to the manufacturer's procedure. |
| Since a software update or a module replacement | Versions mismatched — two systems describing the same road differently | Check module software versions against the vehicle's current specification. | Bring all related modules to matching versions. |
| Features switched off in a settings menu | Nothing — a setting rather than a fault | Check the vehicle's assistance settings before anything else. Common on a used car after a handover. | No repair. Restore the settings. |
| Available but behaving oddly rather than unavailable | The failure that matters — the system is confident and wrong | Take it more seriously than an unavailable message, not less. | Recalibrate and have the sensor checked. |
-
Several functions unavailable at once
- Likely cause
- One shared sensor — they usually look through the same camera or radar
- How to confirm it
- List what has gone. A single fault removing several functions is the norm rather than a coincidence.
- What fixes it
- Repair the shared sensor rather than each function.
-
Sensor area dirty, iced or snow-covered
- Likely cause
- Blinding — the correct response is to report unavailable
- How to confirm it
- Clean behind the badge and the screen in front of the mirror, then retest.
- What fixes it
- No repair. Largest single share of these complaints.
-
Since front-end work, a windscreen, or a knock with no visible mark
- Likely cause
- Alignment — aimed to a fraction of a degree
- How to confirm it
- Ask what happened rather than inspecting for damage.
- What fixes it
- Recalibrate to the manufacturer's procedure.
-
Since a software update or a module replacement
- Likely cause
- Versions mismatched — two systems describing the same road differently
- How to confirm it
- Check module software versions against the vehicle's current specification.
- What fixes it
- Bring all related modules to matching versions.
-
Features switched off in a settings menu
- Likely cause
- Nothing — a setting rather than a fault
- How to confirm it
- Check the vehicle's assistance settings before anything else. Common on a used car after a handover.
- What fixes it
- No repair. Restore the settings.
-
Available but behaving oddly rather than unavailable
- Likely cause
- The failure that matters — the system is confident and wrong
- How to confirm it
- Take it more seriously than an unavailable message, not less.
- What fixes it
- Recalibrate and have the sensor checked.
Codes that produce this symptom (4)
Listed with the codes that most typically present this way first — the likeliest place to start.
- U015C Lost Communication With Automated Driving System Control Module A Typical of this code Moderate
- U02B5 Lost Communication With Front Radar Module B Typical of this code Moderate
- U045D Invalid Data Received From Automated Driving System Control Module A Typical of this code High
- U045A Invalid Data Received From Parking Assist Control Module A Low
Information, not instruction
CarGeek is a reference, not a service manual. Its pages are written from public sources and from what other people have found, never from a manufacturer's own service information, so they can be wrong or incomplete for your particular vehicle. Some of what they describe carries real risk: high voltage, fuel under pressure, stored energy, hot and moving parts.
Have anything you intend to act on checked by a trained person against the manufacturer's own procedure for your vehicle. Nothing here replaces that procedure.
Others with this symptom
Be the first to write this up
Nothing posted about this yet. Whatever you found is worth writing down — even a dead end saves someone the same afternoon.
What makes one worth reading:
- The car — make, model, year and engine. The same fault behaves differently on each.
- What you measured, not only what you replaced.
- What actually fixed it — or that nothing did, which is worth knowing too.
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