U0140 on Toyota
Lost Communication with BCM
U0140 on Toyota vehicles indicates lost communication with bcm. Au7o has documented this code across 1 Toyota model — most commonly on Land Cruiser. 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. Typical repair costs on Toyota range from $250 to $900, depending on the specific model and root cause.
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 Toyota by Model
Toyota Land Cruiser(1 issue)
- 12-Volt Battery Drain and No-Start After Short Parking Periods2024-2025
Multiple owners of the new U.S.-market 2024+ Land Cruiser have reported weak 12-volt batteries, repeated jump-starts, or complete no-start conditions after the vehicle sits for relatively short periods. Reports often mention telematics, accessory modules, or software-related parasitic draw behavior rather than a single failed starter or alternator. The issue is especially frustrating on low-mileage vehicles and can trigger a cascade of warning messages when voltage drops.
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View U0140 across all makes →Frequently Asked Questions
What does U0140 mean on Toyota?▼
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 Toyota specifically, this code is documented across 1 model.
What causes U0140 on Toyota vehicles?▼
Common causes on Toyota: 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 Toyota?▼
Repair costs on Toyota range from $250 to $900, depending on the specific model and root cause.
Which Toyota models have U0140 documented?▼
Au7o has documented U0140 on 1 Toyota model: Land Cruiser.