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DTC codes / U04xx · Invalid data received from a module / U0445

U0445Invalid Data Received From Body Control Module D

U0445 is a communication fault indicating that the Body Control Module D (BCM-D) is sending data that other modules on the vehicle network consider invalid or corrupted. The computer detected a message from BCM-D that failed its internal validity checks, such as a checksum error or missing expected data fields, rather than a complete loss of communication.

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

Symptoms you may notice

  • Illumination of the malfunction indicator lamp (MIL) or a dedicated communication warning light
  • Often no symptoms besides the warning light, especially if the corrupted message is non-critical
  • Intermittent or erratic operation of body functions such as interior lights, door locks, or wipers
  • Unexplained battery drain if the BCM-D remains awake due to communication errors
  • Multiple unrelated warning lights or system messages appearing simultaneously
  • Remote keyless entry or push-button start intermittently failing to respond

Common causes, most likely first

  1. Corroded, loose, or damaged wiring and connectors in the controller area network (CAN) bus or other data bus circuits
  2. Failing Body Control Module D itself, often due to internal circuit faults or water intrusion
  3. Low or unstable battery voltage causing modules to send malformed data frames
  4. Poor ground connections for BCM-D or other modules on the same network segment
  5. Aftermarket accessories or improper electrical repairs introducing noise or incorrect bus termination
  6. Software or firmware corruption in BCM-D requiring reflash or replacement

How to diagnose and fix it

  1. Perform a full system scan with a capable scan tool to record all stored codes and freeze-frame data before clearing anything
  2. Inspect and test the battery, charging system, and all ground connections for voltage drops or corrosion
  3. Visually inspect the wiring harness and connectors at BCM-D and along the data bus for chafing, moisture, or loose pins
  4. Measure bus voltage and resistance with a digital multimeter to check for shorts, opens, or incorrect termination
  5. Consult the factory service information for the specific vehicle to perform guided diagnostics for U0445, including BCM-D power and ground checks
  6. If wiring and power are confirmed good, reflash or replace BCM-D according to the manufacturer's procedure, then clear codes and verify repair

Why U0445 is rarely just a bad module

  • A corrupted message from BCM-D often originates from a marginal ground or low battery voltage rather than a failed module, so always load-test the battery and check grounds before condemning the BCM.
  • U0445 can be set by a single intermittent glitch on the data bus, and clearing the code may be all that is needed if it does not return after a thorough test drive and wiggle test.
  • Aftermarket alarms, remote starters, or improperly installed accessories that tap into the bus can introduce invalid data frames that mimic a failing BCM-D.
  • The code does not always mean BCM-D is faulty; another module on the same bus can corrupt the signal, so check for related communication codes in all modules before replacing parts.
  • Water intrusion into the BCM-D connector or housing is a common hidden cause, especially on vehicles with clogged sunroof drains or cowl leaks, so inspect for moisture and corrosion.

Can I keep driving with U0445?

The vehicle is generally safe to drive because U0445 affects body and convenience functions rather than engine or brake control, but avoid long trips until diagnosed if multiple warning lights are present. Do not ignore persistent battery drain or intermittent electrical failures that could affect safety systems.

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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