U0140 on Cadillac
Lost Communication with BCM
U0140 on Cadillac vehicles indicates lost communication with bcm. Au7o has documented this code across 1 Cadillac model — most commonly on Celestiq. 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.
Common Causes of U0140
- •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
U0140 on Cadillac by Model
Cadillac Celestiq(1 issue)
- Complex Software Integration Issues Across Vehicle Systems2024-2025
As a hand-built, technology-flagship vehicle, the Celestiq experiences occasional software integration issues between its numerous systems including the 55-inch LED display, four-zone smart glass roof, and advanced driver assistance features. Individual systems may temporarily lose communication with each other, requiring a vehicle restart.
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View U0140 across all makes →Frequently Asked Questions
What does U0140 mean on Cadillac?▼
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. On Cadillac specifically, this code is documented across 1 model.
What causes U0140 on Cadillac vehicles?▼
Common causes on Cadillac: 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. Specific causes vary by model and year — see the per-model sections below.
How much does it cost to fix U0140 on a Cadillac?▼
Repair costs vary widely depending on the root cause and specific Cadillac model.
Which Cadillac models have U0140 documented?▼
Au7o has documented U0140 on 1 Cadillac model: Celestiq.