U0433: Invalid ACC Distance Sensor Data
Diagnostic trouble code U0433 indicates that the vehicle's control module has received invalid or erroneous data from the Cruise Control Front Distance Range Sensor, which is part of the Adaptive Cruise Control (ACC) system. This sensor measures the distance between your vehicle and obstacles or vehicles ahead. The fault is classified as a Controller Area Network (CAN) communication error, meaning the data frame transmitted by the distance sensor to the Powertrain Control Module (PCM) or cruise control module is corrupted, implausible, or improperly formatted. It does not typically indicate an open or short circuit in the sensor wiring.
1. Commonly Affected Makes
This is a generic OBD2 code, potentially applicable to any manufacturer using this diagnostic standard.
2. Most Common Causes
- Internal failure of the front distance sensor (radar or lidar)
- Intermittent connection or high resistance in the CAN bus communication wires
- Moisture or corrosion in the front distance sensor connectors
- Electromagnetic interference (EMI) affecting the data signal
- Software fault or need for calibration update in the cruise control module
- Physical obstruction, dirt, or misalignment of the sensor lens/antenna
- Damaged Cruise Control Module (CCM)
3. Symptoms You Will Notice
- Adaptive Cruise Control (ACC) system inoperative or disabled
- Warning lights on the dashboard (e.g., ACC, Check Engine, or cruise control indicator)
4. Step-by-Step Diagnosis
Scan for all stored codes and freeze frame data to confirm U0433 and related codes.
Visually inspect the front distance sensor for physical damage, dirt, or misalignment.
Check the sensor connectors and CAN bus wiring for corrosion, moisture, or damage.
Test the sensor's power and ground circuits with a multimeter.
Use an oscilloscope to check CAN bus signal integrity (voltage levels and waveform).
If no wiring issues found, attempt to recalibrate the sensor using a scan tool.
If recalibration fails, replace the front distance sensor and perform calibration.
If problem persists, test or replace the Cruise Control Module (CCM).
5. Frequently Asked Questions
Is it safe to drive?▼
Driving is possible but not recommended because the ACC system will be disabled, and the fault may affect other safety systems that rely on the distance sensor. Have it diagnosed promptly.
How much does it cost to fix?▼
Repair costs typically range from $200 to $1,200 depending on the root cause. Sensor replacement and calibration can be $400–$800, while module replacement may exceed $1,000.