U0445 Invalid Data from Body Control Module D
The U0445 code indicates that the engine or powertrain control module (ECM/PCM) has received invalid, corrupt, or out-of-range data from the Body Control Module 'D' (BCM 'D') over the CAN bus. This means the physical CAN communication is working, but the data content is faulty—such as impossible sensor values, incorrect checksums, or messages outside expected parameters. The BCM 'D' is a specific instance of the body control module used in vehicles with multiple BCMs or where a particular module handles dedicated functions.
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 BCM 'D' causing corrupted data output
- Electromagnetic interference on the CAN bus altering BCM 'D' messages
- Software version mismatch between BCM 'D' and the receiving module (ECM/PCM)
- Incorrect CAN bus termination or faulty termination resistors
- Low voltage or power fluctuations to the BCM 'D'
- Corrosion or excessive resistance in BCM 'D' connectors
3. Symptoms You Will Notice
- Check Engine Light or Body Control Module warning light on
- Malfunction of body-related features (lights, locks, windows, etc.)
4. Step-by-Step Diagnosis
Scan for all stored codes and freeze frame data to confirm U0445 and related codes.
Inspect CAN bus wiring and connectors at BCM 'D' for damage, corrosion, or loose pins.
Check BCM 'D' power and ground circuits for proper voltage and low resistance.
Verify CAN bus termination resistance (should be ~60 ohms between CAN-H and CAN-L with power off).
Update BCM 'D' and ECM/PCM software to latest versions if mismatch is suspected.
If all else fails, replace BCM 'D' and reprogram as needed.
5. Frequently Asked Questions
Is it safe to drive?▼
Yes, but you may experience intermittent electrical issues. It's best to diagnose and repair soon to avoid further problems.
How much does it cost to fix?▼
Diagnosis typically $100-$200. If BCM replacement is needed, total cost ranges from $500 to $1,200 including parts and labor.