HomeTrouble CodesU0144

U0144 — Lost Communication Body Control Module D

Generic OBD-II · all makesNetwork / communication

U0144 means the vehicle’s network has lost communication with the Body Control Module designated as 'D'. This BCM controls various body‑electrical functions such as lighting, door locks, wipers, and sometimes the immobilizer. When the module cannot be reached on the CAN bus, the PCM stores this trouble code.

Symptoms

What causes it — most likely first

1. Faulty Body Control Module D

The BCM D itself may have an internal electronics failure that prevents it from transmitting or receiving CAN messages.

2. Damaged wiring or connectors in the CAN bus to BCM D

Corrosion, chafed wires, or loose pins in the harness linking BCM D to the vehicle network can interrupt communication.

3. Loss of power or ground to BCM D

A blown fuse, faulty relay, or poor ground connection can deprive the module of voltage, causing it to appear offline.

4. Faulty CAN transceiver or another node on the bus

A malfunctioning transceiver in BCM D or a competing module can bus‑off the network, blocking messages to/from BCM D.

5. Software or calibration glitch in BCM D

Corrupted firmware or an incorrect configuration can cause the module to stop responding on the CAN bus.

6. PCM/ECM communication issue

While rare, a fault in the powertrain control module’s CAN interface could prevent it from seeing BCM D; this is considered only after other causes are ruled out.

How it's diagnosed

  1. Scan for all stored codes and note any related U‑ or B‑codes that may indicate broader network issues.
  2. Check the BCM D fuse and power supply voltages at the module’s connector with the key ON.
  3. Inspect the ground circuit for BCM D for continuity and low resistance.
  4. Visually examine the wiring harness and connectors between BCM D and the CAN bus for damage, corrosion, or loose pins.
  5. Use a CAN bus tester or oscilloscope to verify that CAN_H and CAN_L signals are present and within spec at the BCM D connector.
  6. If power, ground, and bus signals are good, consider substituting a known‑good BCM D or re‑programming the existing unit.

Code facts & related codes

SystemNetwork / communication
StandardizationSAE generic — identical on every make

Frequently asked

Is it common to replace the PCM/ECM to fix U0144?

No. The PCM/ECM is rarely at fault for a lost‑communication code with a specific BCM. Replacing the control module is usually unnecessary and expensive; focus first on the BCM D, its wiring, power, ground, and CAN bus integrity.

Can a weak battery cause U0144?

A severely discharged battery can cause low voltage that may prevent the BCM from operating correctly, potentially triggering the code. However, proper battery voltage should be verified as part of the power‑supply check.

Will clearing the code fix the problem?

Clearing the code only removes the stored fault; if the underlying communication issue persists, the code will return shortly after the vehicle is driven or the network is re‑initialized.

Are aftermarket accessories a possible cause?

Improperly installed aftermarket electronics that tap into the CAN bus or draw excessive current can introduce noise or voltage drops, leading to lost communication with BCM D.