C1A10: Front Radar Sensor / Millimeter Wave Radar Sensor Malfunction
3 vehicles · 2 makes · $250-$1,800 repair
Most Reported On
C1A10 is an OBD-II diagnostic trouble code meaning “Front Radar Sensor / Millimeter Wave Radar Sensor Malfunction.” C1A10 is a manufacturer-specific code (commonly Toyota/Lexus) indicating an internal malfunction of the front millimeter-wave radar sensor assembly. This radar, usually mounted behind the front emblem in the grille, feeds object-detection data to driver-assistance features like adaptive (dynamic radar) cruise control, the pre-collision/automatic emergency braking system, and lane-departure assist. When the module detects the radar is faulty or not responding correctly, it sets this code and typically disables those safety features. It does not affect basic driving but means key crash-avoidance systems may be offline. This code is most commonly reported on 2024-2025 Toyota Land Cruiser, 2023-2025 Lexus IS, and 2023-2025 Lexus RX, with repair costs ranging from $250 to $1,800.
Common Causes
Typical Repair Cost
Based on 3 documented vehicle-specific issues. Actual cost depends on root cause and vehicle.
Diagnostic Tools
To diagnose C1A10, you'll need an OBD-II scanner. Here are our recommendations at every price point.
ANCEL AD310 Classic OBD-II Scanner
by ANCEL
A simple, affordable code reader that reads and clears check engine codes. Great for quick diagnostics on any OBD-II vehicle (1996+).
- Read & clear engine codes
- View freeze frame data
- I/M readiness status
- No batteries or app needed
BlueDriver Pro Bluetooth Scanner
by BlueDriver
Bluetooth OBD-II scanner with a free companion app. Provides enhanced diagnostics, smog readiness, and repair reports sourced from a database of verified fixes.
- Enhanced diagnostics (ABS, SRS, transmission)
- Repair Reports with verified fixes
- Smog check readiness
- Free app (iOS & Android)
LAUNCH CRP123X OBD-II Scanner
by LAUNCH
A professional-grade handheld scanner that reads all four major systems (engine, transmission, ABS, SRS) with live data streaming and graphing.
- Engine, transmission, ABS, SRS diagnostics
- Live data stream & graphing
- AutoVIN for vehicle identification
- Free lifetime updates via Wi-Fi
Autel MaxiCOM MK808S Diagnostic Tool
by Autel
Shop-level diagnostic tablet with bi-directional control, active tests, and full system coverage. Ideal for serious DIYers and small shops.
- All-system diagnostics (25+ modules)
- Bi-directional control & active tests
- Oil reset, EPB, BMS, TPMS, injector coding
- 7-inch touchscreen with Android OS
As an Amazon Associate, we earn from qualifying purchases. Prices are approximate and may vary.
Vehicles Affected (3)
FAQ
What does C1A10 mean?
C1A10 stands for "Front Radar Sensor / Millimeter Wave Radar Sensor Malfunction." C1A10 is a manufacturer-specific code (commonly Toyota/Lexus) indicating an internal malfunction of the front millimeter-wave radar sensor assembly. This radar, usually mounted behind the front emblem in the grille, feeds object-detection data to driver-assistance features like adaptive (dynamic radar) cruise control, the pre-collision/automatic emergency braking system, and lane-departure assist. When the module detects the radar is faulty or not responding correctly, it sets this code and typically disables those safety features. It does not affect basic driving but means key crash-avoidance systems may be offline.
What are the most common causes of C1A10?
The most common causes of C1A10 are: Faulty/internally failed millimeter-wave radar sensor, Sensor knocked out of alignment after a front collision or repair, Obstruction on the sensor face (ice, snow, mud, debris, aftermarket emblem), Damaged wiring or corroded connector to the radar, Sensor calibration/aiming not performed after bumper or grille work, Low system voltage or poor ground, Driving-support ECU fault or software issue. The specific cause varies by vehicle.
How much does it cost to fix C1A10?
Repair costs for C1A10 range from $250 to $1,800, depending on the vehicle and root cause.
Which vehicles are affected by C1A10?
Au7o has documented C1A10 across 3 vehicle models from 2 manufacturers: Lexus, Toyota.
Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.