U0140–U0145 Lost Communication With Body Control Module
This module has stopped talking on the car's data network, so nothing else can hear it.
Can you drive it? This is a communication fault on the car's data network. What it affects depends on the modules involved - a silent engine or gearbox module can bring on warning lights and limp mode, a comfort module only its own features. Check the power, earth and connector of the module named in the code, or the network wiring, first.
Which code is which
Same fault, different cylinder or bank — diagnosed the same way. Several set together usually means one shared cause.
| Code | Definition | Severity |
|---|---|---|
U0140 | Lost Communication With Body Control Module | Investigate soon |
U0141 | Lost Communication With Body Control Module A | Investigate soon |
U0142 | Lost Communication With Body Control Module B | Investigate soon |
U0143 | Lost Communication With Body Control Module C | Investigate soon |
U0144 | Lost Communication With Body Control Module D | Investigate soon |
U0145 | Lost Communication With Body Control Module E | Investigate soon |
The definition
U0140: Lost Communication With Body Control Module.
U0140 is a network code (communication between control modules), defined by the SAE standard - it means the same thing on any make of car, and any generic OBD-II reader will decode it.
What to check first
Cheapest and fastest checks first:
- Check power and earth at the module first - a module with no supply cannot answer.
- Check the two data-bus wires for continuity and for a short between them.
- Scan the other modules: if several report the same module missing, the fault is at that module rather than on the bus.
Reading the code is the easy part
A code names the circuit that complained. What tells you why is watching the sensor behind it while the engine runs — and that is where a code reader stops and a diagnostic tool starts.
VAGPULSE reads your engine ECU's fault codes and the live measuring blocks behind them, and clears the codes once you have fixed the fault. On the engine it also does what a generic OBD reader cannot on a VAG: coding, adaptations, and Stage 1–3 flashing on Bosch ME7 petrol ECUs, with a backup saved every time it reads your ECU.
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Common questions
What does U0140 mean?
U0140 means Lost Communication With Body Control Module. This module has stopped talking on the car's data network, so nothing else can hear it.
Can I drive with U0140?
This is a communication fault on the car's data network. What it affects depends on the modules involved - a silent engine or gearbox module can bring on warning lights and limp mode, a comfort module only its own features. Check the power, earth and connector of the module named in the code, or the network wiring, first.