What Does ACC / LKAS / CMBS Warning — 'Radar Obstructed' or 'Camera Too Hot' Mean?
Reviewed by automotive technicians · Last updated August 22, 2026
Quick Answer
ACC / LKAS / CMBS Warning — 'Radar Obstructed' or 'Camera Too Hot' = Honda Sensing suite (ACC/LKAS/CMBS) has detected that the radar unit (behind the Honda emblem in the grille) or the camera (at the top of the windshield) cannot see clearly. This is usually caused by: (1) heavy rain, snow, or fog — clears when weather improves; (2) direct sunlight hitting the camera at a low angle — clears when sun angle changes; (3) dirt, ice, or bugs on the Honda emblem or windshield camera area; (4) the radar unit has been knocked out of alignment by a minor front-end bump.
Severity: Warning · System: Honda Accord (2018-2025)
DRIVE WITH CAUTION — Repair Soon
Honda Sensing suite (ACC/LKAS/CMBS) has detected that the radar unit (behind the Honda emblem in the grille) or the camera (at the top of the windshield) cannot see clearly. This is usually caused by: (1) heavy rain, snow, or fog — clears when weather improves; (2) direct sunlight hitting the camera at a low angle — clears when sun angle changes; (3) dirt, ice, or bugs on the Honda emblem or windshield camera area; (4) the radar unit has been knocked out of alignment by a minor front-end bump.
What you see: An orange car icon with radar waves, or messages on the MID: 'ACC Cannot Be Used — Radar Sensor Blocked', 'Collision Mitigation System Problem', 'Lane Keeping Assist Problem'
What to Do Right Now
If due to weather: the systems will auto-recover when conditions improve. If due to dirt: clean the Honda emblem in the grille and the windshield area in front of the rearview mirror. If the warning persists in clear weather after cleaning, the radar unit may need recalibration — this requires a Honda dealer visit. The car drives fine — you just lose adaptive cruise and collision braking temporarily.
Emergency Action Guide
URGENCY: DRIVE WITH CAUTION
YELLOW — If due to weather (heavy rain, snow, fog), the systems will auto-recover when conditions improve. If due to dirt: clean the Honda emblem in the front grille and the windshield area in front of the rearview mirror. If the warning persists in clear weather after cleaning, the radar may need recalibration. The car drives fine — you just lose adaptive cruise and collision braking temporarily.
Can you keep driving?
Yes — the car drives completely normally. You only lose the advanced driver-assist features (adaptive cruise control, lane keeping assist, collision mitigation braking). Standard cruise control still works. The car is fully safe to drive — just do not rely on the automatic braking or lane keeping features until the warning clears.
What happens if you ignore it?
LOW — the car is safe to drive. The Honda Sensing features are convenience and supplementary safety systems, not primary safety systems. You still have full manual braking, steering, and standard cruise control. However, if you have become dependent on adaptive cruise or automatic emergency braking, be aware that these features are temporarily unavailable.
Diagnosis & Cost
- Check if the warning appeared during adverse weather — heavy rain, fog, or snow can temporarily block the radar or camera. If so, no action is needed; the systems will resume when conditions improve.
- Clean the radar sensor (behind the Honda emblem in the grille) with a soft damp cloth. Also clean the windshield area in front of the rearview mirror where the camera is located. Dirt, bugs, or road film on these surfaces block the sensors.
- If the warning appeared after a front-end bump or windshield replacement, the radar or camera may have been knocked out of alignment. This requires a Honda dealer recalibration ($300–800).
- If none of the above apply and the warning persists, try parking in a cool, shaded area for 30 minutes. The camera can overheat in direct sun and trigger a 'Camera Too Hot' warning. Once cooled, it should resume normal operation.
| Item | Details |
|---|---|
| Estimated Repair Cost | $0 (clean the sensors or wait for weather to clear) – $300–800 (Honda dealer radar/camera recalibration, required after windshield replacement or front-end impact) |
Repair Cost Estimate
| Option | Est. Cost | Notes |
|---|---|---|
| Do It Yourself | $0 (clean the emblem and windshield); $0 (weather-related — wait for it to clear) | If you have basic tools and mechanical knowledge |
| Mechanic / Dealer | $300-800 for Honda dealer radar recalibration (required after any front bumper removal or minor collision) | Includes diagnostic labor + parts |
About This Data
Dashboard warning light information compiled from Honda owner's manuals, OEM service documentation, SAE J2402 standards, and NHTSA guidance. This is an independent reference — not affiliated with or endorsed by Honda. All brand names, model names, and dashboard symbols are trademarks of their respective vehicle manufacturers.
Published: 2026-07-05 · Repair costs are national averages and vary by location. Always get multiple quotes before authorizing repairs.
⚠️ Red dashboard lights demand immediate action — continued driving may cause engine damage or brake failure. When in doubt, pull over and consult a certified mechanic.
By Patricia N. Simmons — Automotive Electronics Specialist
Patricia has spent 12 years researching instrument cluster diagnostics and dashboard warning light systems across 20+ automotive brands. She has analyzed over 500 OEM owner's manuals and SAE standards to compile this reference. Her experience includes field diagnostics with certified technicians, cross-referencing NHTSA technical service bulletins, and building practical decision guides that help drivers understand exactly what each warning light means — and whether they should keep driving or pull over immediately.
About Patricia · Published: 2026-07-05 · Updated: August 22, 2026
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Frequently Asked Questions
Can I drive my Honda Accord with the ACC / LKAS / CMBS Warning — 'Radar Obstructed' or 'Camera Too Hot' on?
Yes, but with caution. Drive directly to a mechanic and avoid hard acceleration or highway speeds. The vehicle is drivable but the affected system is not functioning correctly.
How much does it cost to fix the ACC / LKAS / CMBS Warning — 'Radar Obstructed' or 'Camera Too Hot' on a Honda Accord?
DIY cost estimate: $0 (clean the emblem and windshield); $0 (weather-related — wait for it to clear). Mechanic/dealer estimate: $300-800 for Honda dealer radar recalibration (required after any front bumper removal or minor collision). Costs vary by location, shop rate, and whether additional components are found to be damaged during diagnosis. Always get 2-3 quotes before authorizing repairs.
What causes the ACC / LKAS / CMBS Warning — 'Radar Obstructed' or 'Camera Too Hot' to come on in a Honda Accord?
Honda Sensing suite (ACC/LKAS/CMBS) has detected that the radar unit (behind the Honda emblem in the grille) or the camera (at the top of the windshield) cannot see clearly. This is usually caused by:. The most common causes vary by model year and driving conditions. See the troubleshooting section above for model-specific diagnostic guidance.
Why does the Honda Sensing warning come on in the rain?
The radar unit behind the front grille cannot distinguish between rain drops and actual objects when the rain is heavy enough. The system correctly disables itself rather than risk false emergency braking events. This is normal behavior and not a defect. The system will automatically resume when the rain subsides.
Do I need to go to a Honda dealer for radar recalibration?
Yes — the radar and camera calibration requires Honda-specific tools (the Acura/Honda radar aiming target and the HDS diagnostic system). Independent shops generally do not have this equipment. The recalibration takes 1–2 hours and costs $300–800 at a dealer. It is required after ANY front bumper removal, windshield replacement, or impact that may have shifted the radar or camera.
Will the Honda Sensing warning affect my car's ability to pass inspection?
No — the Honda Sensing system is not part of any state safety or emissions inspection. The warning does not affect the vehicle's compliance with any federal or state requirements. It is purely a convenience/supplementary safety system. You can legally drive with the warning indefinitely, though you will not have the driver-assist features.
Can I disable the Honda Sensing warning message?
You can press and hold the MAIN button on the steering wheel to disable the adaptive cruise control system, which will stop the warning message from appearing. However, this also disables the automatic emergency braking feature. A better approach is to fix the underlying issue (clean sensors, recalibrate if needed) so all safety features are operational.