MotorBitU0140: Lost Communication With Body Control Module
Lost comms with the BCM. Interior electronics, lights, or locks may misbehave along with a MIL or multiple lamps.
Educational OBD2 information. Confirm on your vehicle with a scan tool. MotorBit can read this code, freeze frame, and live data over an ELM327 adapter.
What U0140 means
A module did not receive BCM messages in time.
Why the check engine light comes on
Body and powertrain networks are linked. A BCM dropout can set engine-related lamps.
Common causes
- Low voltage
- BCM connector
- Water in a module
- CAN fault
Typical symptoms
- Interior electrical gremlins
- Multiple warning lights
What to do next
- Battery/charging system test.
- Look for water intrusion under carpets and in kick panels.
How MotorBit helps
Open MotorBit, connect your ELM327, and read U0140 with freeze frame (RPM, load, temperature, speed at the moment the fault set). Then watch live PIDs and fuel trims instead of replacing parts by guesswork. When the repair is verified, clear the code and re-check monitors.
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FAQ
Is U0140 serious?
Severity is listed as medium on this page. Misfire, crank/cam, and communication codes deserve faster attention than a tiny EVAP leak.
Will disconnecting the battery clear U0140?
It may hide the lamp temporarily, but the fault usually returns and you lose freeze-frame evidence. Scan first, then clear after the repair.
Can MotorBit clear U0140?
Yes, after you understand the cause. Clearing without a repair is how the light comes back on the next drive cycle.