2025-2027 Lucid Gravity Collision Sensor: ADAS Errors, Calibration, and Replacement

Symptoms of a Failing Collision Avoidance Sensor

A problem with the front collision avoidance sensor on a 2025-2027 Lucid Gravity will primarily disable or degrade the vehicle's advanced safety systems. You will likely see specific error messages on the driver display.

• Warning Messages on the Display: The most common symptom is a message on the instrument panel indicating a fault. This may read "Radar sensor front Sensor blocked See Manual," "ACC unavailable," or a general ADAS fault light. Lucid's system may also show a warning that a sensor or camera is blocked and gray out the related features in the DreamDrive menu.
• Automatic Emergency Braking (AEB) and Forward Collision Warning Disabled: The vehicle will alert you that these critical safety features are inactive. This is a serious safety concern, as the car will not automatically brake to prevent or mitigate a frontal collision.
• Adaptive Cruise Control (ACC) Inoperative: You will be unable to engage ACC, or it may disengage unexpectedly during use. The system relies on the front radar to maintain distance from the vehicle ahead.
• False Alerts or "Phantom Braking": A misaligned or failing sensor can incorrectly detect an obstacle, causing the Forward Collision Warning to sound an alarm or the AEB system to apply the brakes suddenly and without reason.
• Intermittent Functionality: The systems may work sometimes but fail in certain conditions, such as in heavy rain or direct sunlight, which can sometimes indicate an underlying sensor issue rather than just a temporary blockage.

Known Issues, Recalls, and TSBs for 2025-2027 Lucid Gravity

As a relatively new vehicle, long-term failure patterns for the collision avoidance sensor are still emerging. As of mid-2026, there are no specific NHTSA recalls or Technical Service Bulletins (TSBs) for the collision avoidance sensor (part number P21-G70000-04) on the Lucid Gravity.

However, buyers and owners should be aware of several broader issues affecting the Gravity that can sometimes present symptoms similar to a sensor failure:

• General Software and ADAS Glitches: Early owners have reported a range of software-related problems, including false safety alerts and inconsistent behavior from the DreamDrive ADAS suite. Some owners have reported the hands-free driving system becoming unavailable or "ping-ponging" in the lane, which can be related to sensor data processing. A general "Drive system fault" message can sometimes be triggered by an ADAS sensor issue.
• Recalls for Other Systems: The 2025-2026 Gravity has been subject to several safety recalls, though none directly involve the front radar. These include issues with second-row seatbelt anchors (NHTSA ID: 26V192), rearview camera software (NHTSA ID: 26V018), and front seat backrest covers. While unrelated, this context is important when evaluating the overall history of a used vehicle.

Buying a Used Collision Avoidance Sensor: What to Check

Purchasing a used OEM sensor can offer significant savings over a new part, but careful inspection is critical for this sensitive electronic component. An improperly functioning used sensor is not just a waste of money—it's a safety risk.

1. Verify the Part Number

The part number must be an exact match. For this application, you are looking for Lucid part number P21-G70000-04. Different part numbers may be for different trim levels or model years and will not communicate correctly with your vehicle's systems.

2. Physical Inspection

Before purchasing, physically inspect the used sensor for any signs of damage:

• Lens/Face: Check for any cracks, deep scuffs, or signs of melting. The radar waves transmit through this surface, and damage can distort the signal.
• Housing: Look for cracks or damage to the plastic body of the sensor. Ensure all mounting tabs are intact and not broken or repaired.
• Connector: The electrical connector pins should be straight, clean, and free of any corrosion (greenish powder). Bent or damaged pins will prevent it from working.
• Signs of Impact: Avoid any sensor that shows signs of being involved in a collision. Even a minor impact can damage the delicate internal components and knock it out of alignment permanently. Ask the recycler about the donor vehicle's condition; a part from a front-end collision should be avoided.

3. Why Used OEM is Better Than Aftermarket

For ADAS components, using a recycled OEM part is strongly recommended over a new aftermarket part. The OEM sensor is designed and tested to work perfectly with the Lucid Gravity's specific software and calibration procedures. Aftermarket sensors often have issues with software compatibility, leading to calibration failures or unreliable performance, which can be dangerous.

Replacement and Calibration

Replacing a collision avoidance sensor is a two-part process: physical installation and electronic calibration. While the physical swap may seem straightforward, the calibration is complex and requires special equipment, making this job unsuitable for most DIY mechanics.

Installation Difficulty

• Physical Installation: 2 out of 5. This typically involves removing the front bumper cover or grille to access the sensor, unbolting the old unit, and plugging in the new one.
• Electronic Calibration: 5 out of 5. This is a job for a Lucid Service Center or a specialty independent shop with the correct OEM-level diagnostic tools and calibration targets.

The Calibration Process

Calibration aims the sensor so it knows exactly where it is in relation to the car's centerline and the road. The process involves:

1. Static Calibration: The vehicle is parked on a perfectly level surface in front of a special target board or reflector. A technician uses a diagnostic tool to put the sensor in calibration mode, and the sensor adjusts itself based on its readings from the target.
2. Dynamic Calibration: This may be required in addition to static calibration. It involves driving the vehicle under specific conditions (e.g., on a straight road with clear lane markings at a certain speed) to allow the sensor to fine-tune its alignment.

This procedure is also required after other services like a wheel alignment or suspension work, as changes to the vehicle's ride height can alter the sensor's aim.

Cost of Replacement

Prices can vary based on location and the specific service center. As this is a dealer-only part for a new luxury vehicle, expect costs to be high.

Frequently Asked Questions (FAQ)