U0140: Lost Communication with BCM
13 vehicles · 9 makes · $100-$2,500 repair
Most Reported On
U0140 is an OBD-II diagnostic trouble code meaning “Lost Communication with BCM.” U0140 is a network communication code meaning a module has lost communication with the body control module (BCM) over the vehicle's data bus. The BCM oversees many body and convenience functions — lighting, door locks, windows, wipers, anti-theft, and gateway communications — so losing contact with it can cause a wide range of seemingly unrelated electrical problems and warning lights. This is typically a wiring, connector, power/ground, or bus fault, or a failure of the BCM itself. Because the BCM often acts as a communication hub, this code can appear alongside other 'lost communication' codes. This code is most commonly reported on 2000-2008 Jaguar S-TYPE, 2004-2012 Jaguar XJ, and 2005-2008 Dodge Magnum, plus 10 other vehicles, with repair costs ranging from $100 to $2,500.
Common Causes
Typical Repair Cost
Based on 13 documented vehicle-specific issues. Actual cost depends on root cause and vehicle.
Diagnostic Tools
To diagnose U0140, you'll need an OBD-II scanner. Here are our recommendations at every price point.
ANCEL AD310 Classic OBD-II Scanner
by ANCEL
A simple, affordable code reader that reads and clears check engine codes. Great for quick diagnostics on any OBD-II vehicle (1996+).
- Read & clear engine codes
- View freeze frame data
- I/M readiness status
- No batteries or app needed
BlueDriver Pro Bluetooth Scanner
by BlueDriver
Bluetooth OBD-II scanner with a free companion app. Provides enhanced diagnostics, smog readiness, and repair reports sourced from a database of verified fixes.
- Enhanced diagnostics (ABS, SRS, transmission)
- Repair Reports with verified fixes
- Smog check readiness
- Free app (iOS & Android)
LAUNCH CRP123X OBD-II Scanner
by LAUNCH
A professional-grade handheld scanner that reads all four major systems (engine, transmission, ABS, SRS) with live data streaming and graphing.
- Engine, transmission, ABS, SRS diagnostics
- Live data stream & graphing
- AutoVIN for vehicle identification
- Free lifetime updates via Wi-Fi
Autel MaxiCOM MK808S Diagnostic Tool
by Autel
Shop-level diagnostic tablet with bi-directional control, active tests, and full system coverage. Ideal for serious DIYers and small shops.
- All-system diagnostics (25+ modules)
- Bi-directional control & active tests
- Oil reset, EPB, BMS, TPMS, injector coding
- 7-inch touchscreen with Android OS
As an Amazon Associate, we earn from qualifying purchases. Prices are approximate and may vary.
Vehicles Affected (13)
FAQ
What does U0140 mean?
U0140 stands for "Lost Communication with BCM." U0140 is a network communication code meaning a module has lost communication with the body control module (BCM) over the vehicle's data bus. The BCM oversees many body and convenience functions — lighting, door locks, windows, wipers, anti-theft, and gateway communications — so losing contact with it can cause a wide range of seemingly unrelated electrical problems and warning lights. This is typically a wiring, connector, power/ground, or bus fault, or a failure of the BCM itself. Because the BCM often acts as a communication hub, this code can appear alongside other 'lost communication' codes.
What are the most common causes of U0140?
The most common causes of U0140 are: Loss of power or ground to the BCM, CAN/data bus wiring damage, short, or open circuit, Corroded, loose, or damaged BCM connectors, Blown fuse feeding the BCM, Failed body control module, Water intrusion or corrosion in the harness, Another module faulting the shared data bus. The specific cause varies by vehicle.
How much does it cost to fix U0140?
Repair costs for U0140 range from $100 to $2,500, depending on the vehicle and root cause.
Which vehicles are affected by U0140?
Au7o has documented U0140 across 13 vehicle models from 9 manufacturers: Cadillac, Chevrolet, Dodge, Ford, GMC, Jaguar, Jeep, Land Rover, Toyota.
Sources (10)
- NHTSADodge Magnum Electrical System Problems - NHTSA Complaints
- owner-reportDodge Magnum Reliability and Common Problems
- NHTSANHTSA Vehicle Complaints for 2015 GMC Yukon XL
- videoYouTube - Diagnosing and Fixing Steering Column Lock Actuator Noise on GMC Yukon XL
- ForumReddit r/ChevyEquinox thread discussing 2024 Equinox EV infotainment freezing and software glitches
- videoYouTube video by a known automotive tech channel showing troubleshooting of 2024 Chevrolet Equinox EV infotainment reboot issues
- NHTSANHTSA complaints for 2021 Cadillac Escalade ESV battery drain and no-start issues
- ForumOwner forum discussions of 2024 Land Cruiser dead 12V battery and parasitic draw
- ForumReddit r/cadillac Thread Discussing Software Integration Problems in Cadillac Celestiq
- ForumReddit r/MustangMachE Thread Discussing 12V Battery Drain and No-Start Issues
Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.