Check Engine Code
U0140
Lost Communication With Body Control Module (BCM)
What U0140 means
U0140 is a network (CAN bus) communication code: modules have stopped receiving messages from the Body Control Module, which manages lights, locks, windows, and many comfort systems. It usually points to wiring, power/ground, or a failed BCM.
Symptoms
- Multiple warning lights and unrelated fault codes at once
- Non-working accessories — lights, locks, windows, wipers
- Intermittent electrical gremlins
- Possible no-start
Likely causes (most common first)
- CAN bus wiring fault — chafed, shorted, or open circuit
- Blown fuse or bad power/ground to the BCM
- Corroded or loose module connector
- Low or unstable battery voltage
- Failed Body Control Module
Can I keep driving?
Check the battery and grounds first — low voltage causes many U-codes. Persistent BCM comm loss can disable safety systems, so get it diagnosed.
Typical repair cost
DIY fixes can start near $50 (parts only). Shop repairs for U0140 typically run up to $900 depending on the underlying cause and vehicle. Start with the most common cause — CAN bus wiring fault — chafed, shorted, or open circuit — before throwing parts at it.
Recommended parts & tools for U0140
Our buyer’s guides cover the tools and parts that pair with AXLY:
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