OBD-II trouble code
U0235: Lost Communication With Cruise Control Front Distance Range Sensor
A module on the network can no longer hear from the front distance range sensor — the forward-facing radar that adaptive cruise control and collision-avoidance systems rely on. Those driver-assist features shut off, but normal driving is unaffected.
Quick facts
- System
- Network
- Category
- Network Communication
- Severity
- Medium severity
- Drivable
- Usually safe to drive short-term
- Repair cost range
- $150 – $1,500
- DIY difficulty
- Shop recommended
What does U0235 mean?
U0235 sets when a module on the vehicle's communication network — typically the cruise control or driver-assistance controller — stops receiving messages from the cruise control front distance range sensor. This sensor is the forward-facing radar (sometimes paired with a camera) usually mounted behind the grille, in the front bumper, or near the windshield. It measures the distance and closing speed to vehicles ahead, and that data is what lets adaptive cruise control hold a set following gap, and what feeds forward-collision warning and automatic emergency braking. When the controller can no longer hear that sensor on the bus, it logs U0235 and shuts the affected features down.
As a lost-communication code, the cause is usually electrical rather than a misaimed radar. The sensor may have lost power or ground through a blown fuse, a corroded ground, or a wiring fault. The bus wiring between the sensor and its controller may be damaged, or the connectors corroded or loose. Because the sensor lives at the front of the vehicle, it's exposed to road debris, moisture, and minor front-end impacts that can disturb its connector or harness — a low-speed bumper tap or grille work is a common trigger. The radar module itself can also fail internally, and occasionally corrupted software or a wider bus fault makes it appear to drop off the network even though it's functional.
The practical effect is that adaptive cruise control, forward-collision warning, and automatic emergency braking will be disabled, usually with a warning light or message telling the driver those systems are unavailable. The vehicle still drives, steers, brakes, and accelerates normally under the driver's control, so U0235 is a medium-severity, drivable fault. The catch is that the safety features you may have come to rely on are off until it's fixed, so it should be diagnosed without long delay — and after any front-end repair, the sensor often needs to be re-aimed and calibrated.
Common causes
- Blown fuse feeding the front distance range (radar) sensor
- Corroded or loose ground for the sensor
- Damaged communication-bus wiring between the sensor and its controller
- Corroded, loose, or backed-out connectors at the sensor
- Front-end impact, grille, or bumper work that disturbed the sensor or harness
- Water or debris intrusion at the sensor connector
- Internally failed radar / distance range sensor
- A wider bus fault making the sensor appear off the network
Symptoms
- Adaptive cruise control unavailable or won't engage
- Forward-collision warning and automatic emergency braking disabled
- Warning light or message that driver-assist systems are unavailable
- Possible 'service' or radar-system message on the display
- Cruise control may revert to standard (non-adaptive) operation or not work at all
- Other communication codes stored if a wider bus fault is present
Diagnostic steps
- 1.Scan all modules and record codes — note whether U0235 is alone or with other communication codes.
- 2.Locate the front distance range sensor for the specific vehicle (commonly behind the grille, in the bumper, or near the windshield).
- 3.Confirm the sensor has power and a good ground; check its fuse(s).
- 4.Inspect the sensor connector and harness for corrosion, water/debris intrusion, looseness, and damage — pay close attention after any front-end work.
- 5.Check the communication wiring between the sensor and its controller for continuity and shorts.
- 6.If power, ground, and wiring are good but communication is still lost, the sensor is likely failed; replace it, then perform the required radar aiming/calibration per the manufacturer procedure.
Repair cost
$150 – $1,500
A fuse, ground, or connector repair is the cheapest fix at $150-$400 including diagnosis. Wiring repair runs $250-$600. Replacing the front radar/distance sensor is the expensive case at $700-$1,500+, and it almost always requires a dealer-level aiming and calibration afterward, which adds labor. Even when only the bumper or grille is repaired, the radar usually needs recalibration to clear U0235 reliably.
Estimate your repair
Run the numbers for your vehicle
Open the Repair Cost Estimator with module communication / can bus diagnosis preselected. Adjust labor rate and vehicle category to fit your situation.
DIY vs shop
Leave this one to a qualified shop. It typically involves emissions-critical components, refrigerant handling, or other work that requires manufacturer-grade tooling, training, or certification. DIY attempts often produce a more expensive problem than the original code.