Lost Communication with Body Control Module D
Diagnostic trouble code U0144 indicates a loss of communication between the powertrain control module (PCM/ECM) and the Body Control Module 'D' (BCM 'D'). This means the PCM is no longer receiving or transmitting data over the vehicle's communication network (typically the CAN bus) with this specific module, which manages various body electrical functions. According to SAE J2012, U0xxx codes denote network communication faults, with the last digit identifying the specific module—'4' designates BCM 'D'.
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 Body Control Module 'D' (BCM 'D')
- Open or short circuit in the CAN bus communication lines (CAN High or CAN Low)
- Power or ground supply issues to the BCM 'D'
- Damaged, corroded, or bent pins in the module connector
- Fault in the powertrain control module (PCM/ECM)
- Interruption or excessive resistance in the CAN network termination
3. Symptoms You Will Notice
- Malfunction indicator lamp (MIL) illuminated
- Inoperative body electrical functions (e.g., interior lights, power windows, door locks)
- Erratic or no response from body control systems
4. Step-by-Step Diagnosis
Scan for all stored codes and freeze frame data
Inspect the BCM 'D' connector for corrosion, damage, or bent pins
Check for proper power and ground at the BCM 'D'
Test CAN bus wiring for opens, shorts, or high resistance between PCM and BCM 'D'
Verify CAN network termination resistance (typically 60 ohms on a healthy bus)
If all else is okay, suspect a faulty BCM 'D' or PCM
5. Frequently Asked Questions
Is it safe to drive?▼
The vehicle may still be drivable, but some body electrical functions may not work. It is recommended to diagnose and repair the issue promptly to avoid further electrical problems.
How much does it cost to fix?▼
Repair costs vary widely depending on the root cause. Diagnosing a communication fault typically costs $100-$200. Replacing a BCM can range from $400 to $800 including parts and labor, while wiring repairs may be less expensive.