U0140: Lost Communication With Body Control Module
U0140 means Lost Communication With Body Control Module. Another module has stopped receiving messages from the body control module (lights, locks, wipers and more).
CodeU0140
SystemNetwork communication
SeverityHigh
TypeGeneric network communication
Can I keep driving? Limit driving and diagnose promptly. Continued driving can cause damage, stalling or limp mode.
Common symptoms
- Several warning lights at once
- Modules or features not working
- Possible no-start or limp mode, depending on the module
Possible causes
- Low battery voltage or poor ground
- Blown fuse or lost power to the module
- Damaged CAN bus wiring or connector
- Failed module
- Aftermarket accessories tapped into the network
How to diagnose U0140
- Check battery voltage and grounds first.
- Scan all modules to see which ones do not respond.
- Check power and ground to the non-responding module.
- Measure resistance between CAN-H and CAN-L at the diagnostic connector with the battery disconnected; many high-speed CAN networks read about 60 Ω.
- Inspect wiring and connectors along the bus.
What the code means, digit by digit
UNetwork communication0Generic (SAE) code1Sub-system40Specific fault
Generic codes have the same definition on every OBD-II vehicle (petrol cars from model year 1996 in the US, 2001 in the EU; diesels later). Manufacturers can add their own enhanced codes; those are not listed here.
Related codes
- U0155 Lost Communication With Instrument Panel Cluster (IPC) Control Module
- U0121 Lost Communication With Anti-Lock Brake System (ABS) Control Module
- U0101 Lost Communication With TCM
- U0100 Lost Communication With ECM/PCM "A"
- U0073 Control Module Communication Bus "A" Off
- U0001 High Speed CAN Communication Bus
General guidance only. Fault codes describe what the engine computer saw, not which part failed: confirm with testing before replacing parts, and follow the vehicle's service information.