OBD-II trouble code
U0433: Invalid Data Received From Cruise Control Front Distance Range Sensor
A module is receiving messages from the cruise control front distance range sensor, but the data inside them is implausible or out of range. The link is alive — the content is wrong. Can disable adaptive cruise and forward-collision features.
Quick facts
- System
- Network
- Category
- Network Communication
- Severity
- Medium severity
- Drivable
- Usually safe to drive short-term
- Repair cost range
- $100 – $1,300
- DIY difficulty
- Shop recommended
What does U0433 mean?
The cruise control front distance range sensor is the forward-facing radar (and on some vehicles the camera or lidar) that measures the distance and closing speed to the vehicle ahead. It is the core input for adaptive cruise control (ACC), and its data is often shared with forward-collision warning and automatic emergency braking. This sensor or its module broadcasts the range data to the modules that use it. U0433 sets when a receiving module is still hearing from the front distance range sensor, but the data in its messages is invalid: a value is out of range, implausible, or contradicts what other sensors see. The link is alive; the content can't be trusted. That is the key difference from a lost-communication code, which means the sensor has gone completely silent.
Because the fault is bad data rather than a dead bus, the causes cluster around whatever makes the sensor broadcast wrong information. The single most common real-world source is anything blocking or mis-aiming the radar: ice, snow, mud, road grime, or a bug-covered emblem or bumper cover in front of the sensor, or — very often — a sensor knocked out of alignment by a minor front-end impact, a bumper repair, or a windshield or grille replacement without recalibration. A failing sensor, low system voltage, or corroded connectors and wiring at the front of the vehicle can also produce implausible data. The sensor's software can be at fault if it is outdated, corrupted, or was never recalibrated after front-end work, and electrical noise or damaged bus wiring can corrupt otherwise-good messages in transit.
Symptoms center on the driver-assist features. You will usually see a check engine light and messages that adaptive cruise control, forward-collision warning, or automatic emergency braking are unavailable, and those features will be disabled because the module won't act on distance data it can't trust. The vehicle stays fully driveable — base engine, brakes, and steering are unaffected, and conventional (non-adaptive) cruise may still work on some vehicles — which is why U0433 is medium rather than high severity. The important caution is not to rely on the disabled safety assists until the fault is fixed. Because U0433 often follows front-end service, a recalibration is frequently the cure; and because it can be secondary to a specific radar code, read the full list, since a companion sensor or 'radar blocked/misaligned' code often names the real root cause.
Common causes
- Radar sensor blocked by ice, snow, mud, or road grime, or an obstruction on the emblem/bumper
- Sensor knocked out of alignment by a minor front impact, bumper repair, or grille/windshield work
- Front distance range sensor not recalibrated after front-end service
- Failing radar/distance sensor (internal fault)
- Low system voltage or a weak battery/charging system
- Corroded connectors or damaged wiring at the front of the vehicle
- Outdated, corrupted, or mismatched sensor software
- Electrical noise or damaged bus wiring corrupting messages in transit
Symptoms
- Check engine light with 'adaptive cruise unavailable' or similar driver-assist message
- Adaptive cruise control disabled or refusing to set
- Forward-collision warning and automatic emergency braking unavailable
- Warning to clean the front sensor/radar
- Companion radar sensor or 'sensor blocked/misaligned' codes stored alongside U0433
- Vehicle otherwise driving normally — power, braking, and steering unaffected
Diagnostic steps
- 1.Read ALL stored codes first — U0433 is often secondary to a specific radar/distance-sensor code that names the fault.
- 2.Check the sensor face and the area in front of it for ice, snow, mud, grime, or an obstruction, and clean it.
- 3.Ask about recent front-end work — a bumper, grille, or windshield job without recalibration is a very common trigger.
- 4.Check battery and charging system voltage; low voltage causes implausible sensor data.
- 5.Inspect front-end connectors and wiring to the sensor for corrosion and damage.
- 6.Perform the manufacturer's radar/distance-sensor alignment and calibration procedure.
- 7.Verify the sensor has the correct, current software, then address companion codes before condemning it.
Repair cost
$100 – $1,300
Cost depends on what is producing the bad data. Cleaning a blocked sensor is essentially free. A radar sensor alignment/calibration is commonly $150-$400. Repairing front-end wiring or a connector varies with access. The front distance range radar sensor itself is the expensive part, frequently $600-$1,300 installed and calibrated depending on the vehicle. Correcting low voltage varies, and a software update is $100-$300 — but replacement should only follow diagnosis, since blockage or misalignment is a far more common and cheaper cause.
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.