Fault-Code Library · Network communication
U0140: Lost communication with body control module
One or more modules have lost communication with the body control module.
Common symptoms
- •Multiple electrical warnings
- •Lighting or locking faults
- •Battery drain
- •Intermittent no-start
Likely causes
- •Weak battery
- •Water ingress
- •Body-module power or ground fault
- •CAN wiring problem
First checks
- •Check battery health and charging
- •Scan the complete vehicle
- •Inspect known water-entry areas, module connectors, powers, and grounds
Important
Water ingress and low voltage can create widespread network faults; correct the root condition before module replacement.
A fault code identifies a detected condition, not a failed part. Confirm manufacturer-specific subcodes and live data.
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