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DTC codes / U04xx · Invalid data received from a module / U047B

U047BInvalid Data Received From Restraints System Sensor K

U047B is a communication fault where the restraints control module (RCM) or airbag control unit receives invalid or corrupted data from a specific restraints system sensor designated as 'K'. The computer has detected that the sensor's signal is outside the expected range, missing, or fails plausibility checks, so it cannot trust the data for airbag deployment decisions.

SystemNetwork
Code typeGeneric (all makes)
SeverityHigh
Fix difficultyProfessional
AreaInvalid data received from a module

Symptoms you may notice

  • Airbag warning light illuminated on the instrument cluster
  • Supplemental restraint system (SRS) warning message displayed on the driver information center
  • Airbag system may be disabled, offering no protection in a collision
  • Often no symptoms besides the warning light
  • Intermittent warning light that comes and goes with temperature or vibration
  • Other restraint-related warnings or chimes may accompany the light

Common causes, most likely first

  1. Faulty restraints system sensor K itself (internal failure or contamination)
  2. Damaged or chafed wiring harness at the sensor connector or along the body routing
  3. Corroded or loose electrical connector at the sensor or RCM
  4. Water intrusion or moisture in the sensor connector or module
  5. Failed restraints control module (RCM) or airbag control unit
  6. Software or calibration issue in the RCM requiring reprogramming
  7. Aftermarket accessories or previous collision repair disturbing sensor wiring

How to diagnose and fix it

  1. Connect a scan tool and retrieve all stored codes from the restraints control module to confirm U047B and check for related sensor codes
  2. Visually inspect sensor K and its connector for corrosion, damage, or loose pins, and check for water intrusion
  3. Perform a wiggle test on the sensor harness while monitoring live data to detect intermittent connections
  4. Measure resistance and voltage on the sensor circuit according to the manufacturer's service information to verify signal integrity
  5. Check for technical service bulletins (TSBs) or software updates for the RCM that address invalid data faults
  6. If the sensor and wiring test good, substitute a known-good sensor K and clear codes to see if the fault returns
  7. If the fault persists after sensor replacement, diagnose or replace the restraints control module as the last step

What most technicians miss on U047B

  • A weak or failing battery or charging system can cause momentary voltage drops that corrupt sensor data and set U047B without any sensor fault.
  • The sensor designated 'K' varies by manufacturer and model year, so always consult the specific service information to identify its exact location and function before testing.
  • Aftermarket seat covers, phone chargers, or accessories plugged into the same circuit can introduce electrical noise that the RCM interprets as invalid sensor data.
  • U047B can be stored as a history code after a low-voltage event or jump-start, and may not indicate a current fault if the light is off and the code does not return after clearing.
  • A poor ground connection at the RCM or sensor can cause invalid data that mimics a failed sensor, so always verify ground integrity before replacing parts.

Can I keep driving with U047B?

Because the airbag system may be disabled, the vehicle should not be driven until the fault is diagnosed and repaired; if you must move it, drive directly to a repair facility and avoid any situation where airbag deployment could be needed.

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.

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