Parts
$0-700+
U0140 — Lost Communication With Body Control Module
CAUTIONIs it safe to drive? The body control module is offline on the network. Accessories like windows, locks, and lights may not respond — check fuses and wiring before replacing the module.
What U0140 means
The BCM controls a wide range of body functions and reports through the CAN/LIN bus. Loss of BCM communication usually means its fuse, power supply, or ground is gone — not a failed module. Multiple seemingly unrelated accessories failing at once is the tell.
Most likely causes (in order)
- Blown BCM fuse or lost power/ground
- Corroded or damaged BCM connector
- CAN or LIN bus wiring fault to the BCM
- Failed BCM
Symptoms you might notice
- Power windows or locks dead
- Lighting faults
- Multiple accessories fail simultaneously
What to check first
Find the BCM fuses (often split across multiple boxes) and verify power and ground at the BCM connector. Multiple unrelated accessory failures all at once = BCM power or ground, not individual component failures.
Repair cost & difficulty
Labor
0.5-4 hr
Difficulty
DIY-friendly