U0431 High Generic / SAE

U0431: Invalid Data Received From Body Control Module A

Network and Communication Invalid Data Received

What to do

Expect a list of faults, and probably a dashboard with several warnings.

The most useful thing you can tell a workshop is where the problems are on the car rather than what they are. Your vehicle has more than one body control module, each looking after a zone of the car. So "everything at the back has stopped working" is far more helpful than listing each item — it points straight at one module rather than at the several things it controls.

Two questions worth answering. Has any water been in the car — a damp carpet, a wet boot floor, a leaking seal? These modules sit low and behind trim, and water is the leading cause. And has any module been replaced or reprogrammed? Each one has to be told what equipment exists in its part of the car, and one fitted without that configuration will report things that are not true.

If several systems across the whole car have gone at once, that is more likely the gateway that links them than several modules failing together.

What this code means

The first body control module is broadcasting data that cannot be accepted as true. See U0400 for the family's framing and U0422 for what a body control module does.

The existence of both U0422 and this code reflects the standard catching up with vehicles that have more than one body module, and the practical meaning is simply that this vehicle's body electronics are distributed rather than centralised.

That distribution is worth understanding because it changes where to look. On a vehicle with several body modules, each covers a zone — front, rear, roof, or left and right — and they are linked to each other and to the rest of the vehicle through a gateway. So the symptoms cluster geographically rather than functionally: everything at one end of the car misbehaving at once, rather than all the lighting or all the locking.

That geographic clustering is the most useful diagnostic observation available, and any owner can supply it. "Everything at the back of the car has stopped" is a far more informative statement than a list of individual faults, and it points directly at one module and its supply rather than at the several parts it serves.

The counting logic applies as elsewhere. Several body modules reporting at once points at the gateway or a shared supply. One alone points at that module's own zone — its connector, its supply, and the water ingress that is the leading cause throughout this area.

And the configuration point from U0422 applies with more force on a zoned architecture, because each module has to be told which equipment exists in its zone. A module replaced without that reports equipment the vehicle does not have, or fails to report equipment it does.

Likely causes

Start here

Water ingress into module · moderate
Faulty body control module · specialist
Incorrect module configuration after replacement · specialist
Corroded or loose connector · easy

Less common

Faulty gateway module · specialist
Damaged data bus wiring · moderate

Symptoms

Components involved

Information, not instruction

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Have anything you intend to act on checked by a trained person against the manufacturer's own procedure for your vehicle. Nothing here replaces that procedure.

Community experience

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