01 U0020 Low Speed CAN Communication Bus Performance • 02 What Happens If You Drive a Keyless Car Without the Key? • 03 Front Wheel Vibration at High Speed: Troubleshooting and Fi… • 04 Petrol vs. Diesel vs. Electric Cars: 2024 Showdown - Pick Y… • 05 Unusual Fluid Found Under Vehicles Leaves Drivers Searching… • 06 Petrol vs Diesel: This is Why You Should Consider a Petrol … • 07 P0011 A Camshaft Position - Timing Over Advanced or System … • 08 Overheating, Misfires, and More: Common Engine Problems Cau… • 09 How to Diagnose and Fix Issues with Your Start Engine Push … • 10 This Engine Feature Saves Gas But Could Bankrupt Your Wallet •

DTC codes / U04xx · Invalid data received from a module / U043C

U043CInvalid Data Received From Front Distance Range Sensor - Right

The U043C code means the vehicle's main computer received invalid or missing data from the front distance range sensor mounted on the right side of the vehicle, which is used for systems like adaptive cruise control and forward collision warning. The computer detected that the sensor's messages were corrupted, out of range, or absent when expected, so it flagged the communication fault.

SystemNetwork
Code typeGeneric (all makes)
SeverityMedium
Fix difficultyIntermediate
AreaInvalid data received from a module

Symptoms you may notice

  • A warning light on the dashboard, often accompanied by a message that adaptive cruise control, forward collision alert, or automatic emergency braking is unavailable.
  • The driver may notice no symptoms besides the warning light if the affected system is not currently in use.
  • Adaptive cruise control may fail to engage or may disengage unexpectedly while driving.
  • Forward collision warning or automatic emergency braking may not activate, or may activate erratically without an obstacle.
  • A message indicating a sensor blockage or sensor fault may appear on the driver information display.
  • In some vehicles, the parking assist or lane-keeping systems may also be disabled as a precaution.

Common causes, most likely first

  1. A damaged, corroded, or loose electrical connector at the right front distance range sensor, often due to water intrusion or road debris.
  2. Wiring damage between the sensor and the control module, such as a chafed wire, broken conductor, or short to ground or power.
  3. A failed right front distance range sensor that is unable to transmit valid data.
  4. A software or calibration issue in the sensor or the module that receives its data, requiring a recalibration or software update.
  5. A faulty control module (such as the driver assistance module) that misinterprets or fails to receive the sensor data.
  6. A low or unstable battery voltage that causes communication errors on the controller area network (CAN) bus.
  7. Aftermarket accessories or improper previous repairs that interfere with the sensor's wiring or mounting.

How to diagnose and fix it

  1. Inspect the right front distance range sensor and its connector for physical damage, corrosion, or loose pins, and clean or reseat the connector as needed.
  2. Check the sensor's wiring harness for chafing, breaks, or shorts, and repair any damaged sections.
  3. Verify battery voltage and charging system performance to rule out low voltage causing communication faults.
  4. Use a scan tool to read live data from the right front distance range sensor and compare it with expected values to confirm whether the sensor is reporting invalid data.
  5. Perform a calibration or software update on the sensor and control module according to the manufacturer's procedure.
  6. If the sensor is confirmed faulty, replace it and perform any required calibration or initialization.
  7. Clear the diagnostic trouble codes and road-test the vehicle to verify the repair and ensure the system operates correctly.

Before you replace the right front sensor

  • A loose or corroded connector at the sensor is a far more common cause of U043C than a failed sensor, so always inspect the plug and pins before condemning the part.
  • The code can be set by a low battery or charging system fault that disrupts CAN bus communication, so check voltage and grounds before chasing sensor faults.
  • After any sensor replacement or front-end repair, the sensor usually requires a calibration; skipping this step will often cause the code to return immediately.
  • U043C can be stored alongside codes for other driver assistance systems because a single invalid sensor data stream can disable multiple features that share the same information.
  • A sensor that is physically intact but misaligned due to a minor impact or bumper removal can send invalid data without any visible damage, so check mounting and aim.

Can I keep driving with U043C?

The vehicle remains safe to drive under normal conditions because the affected driver assistance features will be disabled, but you should not rely on adaptive cruise control or forward collision warning until the fault is repaired. Avoid using those systems and have the vehicle diagnosed soon to restore full safety functionality.

Tools that help

Tools we recommend are in the Auto Veteran shop on Amazon. As an Amazon Associate we earn from qualifying purchases.

Guidance is general and written for all OBD-II vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.

Running on fumes Free guides aren't free to make. Top up the tank. Any amount, one time. Fuel the Garage