Symptom
Adaptive cruise control unavailable
The car reports the distance-keeping function unavailable, or it works and then quits mid-journey. The sensor is a radar or camera looking forward, usually behind the grille badge or at the top of the windscreen, which explains the causes people least expect: heavy rain, road spray, a plastered-on layer of dead insects, or a badge that has been replaced. The safety point is specific — the same sensor usually feeds automatic emergency braking, so losing it silently means the car may no longer brake for you while everything else feels entirely normal.
Also described as: adaptive cruise not working, radar cruise unavailable, distance control unavailable, acc not available, cruise control sensor blocked, کروز هوشمند غیرفعال است, crucero adaptativo no disponible, acc no disponible, radar delantero no funciona, المثبت التكيفي غير متاح, الكروز الذكي معطل, الرادار الأمامي لا يعمل
What this usually means
The sensor is a radar or camera looking forward, usually behind the grille badge or at the top of the windscreen, which explains the causes people least expect: heavy rain, road spray, a plastered-on layer of dead insects, or a badge that has been replaced.
The safety point is specific — the same sensor usually feeds automatic emergency braking, so losing it silently means the car may no longer brake for you while everything else feels entirely normal.
Cleaning resolves a large share, and it is the first thing to do rather than the last. A radar behind a badge is blinded by a layer of ice or grime you would not think twice about, and by anything metallic fitted in front of it — an aftermarket badge, a number plate surround, a bumper protector.
Then alignment. These sensors are aimed to a fraction of a degree, so any front-end work — a bumper repair, a windscreen replacement, or a parking knock that left no visible mark — requires recalibration. A sensor that is not blinded and reports unavailable after such work is almost always misaligned rather than failed.
Windscreen replacement deserves naming, because a camera at the top of the screen must be recalibrated afterwards and the glass itself must be the correct specification. A screen fitted without the calibration produces exactly this complaint, sometimes days later.
And disabling itself when uncertain is the designed behaviour, so a system that has switched off is usually working correctly. The failure that matters is a system that stays on while aiming at the wrong part of the road, which is why calibration is not optional.
Working through it
| What you find | Likely cause | How to confirm it | What fixes it |
|---|---|---|---|
| Unavailable in rain, spray or snow, returns in clear weather | The sensor blinded — designed behaviour rather than a fault | Correlate with the conditions. Systems report unavailable when they cannot see reliably. | No repair. Clean the sensor area if it also happens in clear conditions. |
| Unavailable in clear weather, sensor area dirty or iced | Grime, insects, ice or snow across the radar or camera | Look behind the grille badge and at the windscreen in front of the mirror. Clean and retest. | Clean the area. This resolves a large share and costs nothing. |
| Unavailable since a bumper repair, windscreen change or parking knock | Alignment — these sensors are aimed to a fraction of a degree | Ask what work was done, including damage that left no visible mark. | Recalibrate to the manufacturer's procedure. This is not optional and not a guess. |
| Aftermarket badge, plate surround or bumper protector fitted | Something in the sensor's path — metallic items block radar entirely | Establish what has been added in front of the sensor. | Remove it. A radar cannot see through metal, however thin. |
| Unavailable with no obvious cause and no recent work | The sensor, its supply, or a stored fault elsewhere the system depends on | Read the sensor's own codes and check whether stability or speed inputs are also faulted. | Repair as the codes name. Test the supply first, as with every driver-aid module. |
| System stays available but behaves oddly — braking late or early | The dangerous version — aiming at the wrong part of the road while reporting itself healthy | Take this more seriously than an unavailable message. Have the alignment checked. | Recalibrate. A system that reports unavailable is protecting you; one that does not is not. |
-
Unavailable in rain, spray or snow, returns in clear weather
- Likely cause
- The sensor blinded — designed behaviour rather than a fault
- How to confirm it
- Correlate with the conditions. Systems report unavailable when they cannot see reliably.
- What fixes it
- No repair. Clean the sensor area if it also happens in clear conditions.
-
Unavailable in clear weather, sensor area dirty or iced
- Likely cause
- Grime, insects, ice or snow across the radar or camera
- How to confirm it
- Look behind the grille badge and at the windscreen in front of the mirror. Clean and retest.
- What fixes it
- Clean the area. This resolves a large share and costs nothing.
-
Unavailable since a bumper repair, windscreen change or parking knock
- Likely cause
- Alignment — these sensors are aimed to a fraction of a degree
- How to confirm it
- Ask what work was done, including damage that left no visible mark.
- What fixes it
- Recalibrate to the manufacturer's procedure. This is not optional and not a guess.
-
Aftermarket badge, plate surround or bumper protector fitted
- Likely cause
- Something in the sensor's path — metallic items block radar entirely
- How to confirm it
- Establish what has been added in front of the sensor.
- What fixes it
- Remove it. A radar cannot see through metal, however thin.
-
Unavailable with no obvious cause and no recent work
- Likely cause
- The sensor, its supply, or a stored fault elsewhere the system depends on
- How to confirm it
- Read the sensor's own codes and check whether stability or speed inputs are also faulted.
- What fixes it
- Repair as the codes name. Test the supply first, as with every driver-aid module.
-
System stays available but behaves oddly — braking late or early
- Likely cause
- The dangerous version — aiming at the wrong part of the road while reporting itself healthy
- How to confirm it
- Take this more seriously than an unavailable message. Have the alignment checked.
- What fixes it
- Recalibrate. A system that reports unavailable is protecting you; one that does not is not.
Codes that produce this symptom (5)
Listed with the codes that most typically present this way first — the likeliest place to start.
- P2583 Cruise Control Front Distance Range Sensor Single Sensor or Centre Typical of this code Moderate
- P2591 Cruise Control Front Distance Range Sensor Left Typical of this code Moderate
- P2592 Cruise Control Front Distance Range Sensor Right Typical of this code Moderate
- U0104 Lost Communication With Cruise Control Module Typical of this code Low
- U0405 Invalid Data Received From Cruise Control Module Typical of this code Moderate
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.
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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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