U0477 High Generic / SAE

U0477: Invalid Data Received From Restraints System Sensor G

Network and Communication Invalid Data Received

What to do

The airbag warning light means the crash sensing may not work properly, and this one has a specific and unglamorous cause worth raising.

These sensors only work if they are bolted down tightly and flatly to clean, solid metal. They measure the movement of whatever they are attached to — so anything that softens that attachment makes them report a real impact wrongly, while testing perfectly on a bench.

Things that do it: a bolt not tightened properly; underseal, paint or corrosion sprayed or built up between the sensor and the panel; a bracket that has rusted thin; a panel pushed slightly out of shape by a knock; or the wrong bolt used, when the manufacturer specified a particular single-use one.

Ask specifically for the mounting to be inspected, not just the sensor tested. This is the version of the fault that survives a new sensor — because the new one gets bolted onto exactly the same bad mounting, and the light comes back.

As always: do not have the light cleared, and refuse a resistor in place of a sensor.

What this code means

A restraints system sensor is reporting a value that cannot be accepted as true. See U0471 for the family's framing and U0452 for the safety rules.

One check on these sensors is free, takes a minute, and is skipped almost every time: the sensor's mounting is part of the sensor.

An accelerometer reports the motion of whatever it is rigidly attached to. Rigidly is the operative word. Anything that softens or alters that attachment changes the reading, and none of it shows on an electrical test:

A bolt that is not to torque. Under-tightened, the sensor moves fractionally against the panel and reads a damped, delayed version of what the structure actually did.
Anything between the sensor and the metal. Underseal oversprayed during a repair, a layer of paint, a washer that does not belong, corrosion scale, or trapped harness tape.
Corroded or distorted mounting metal. A bracket that has rusted thin, or a panel pushed slightly out of shape in a minor knock, no longer transmits what it used to.
The wrong fastener. These are not general-purpose bolts; several manufacturers specify a single-use fastener and a particular torque, both for good reason.

So the inspection is: is it tight, is it flat against clean bare metal, is the bracket sound, and is the fastener the right one. A sensor that passes every electrical measurement and reads wrongly under load is nearly always a mounting problem rather than a failed part — and it is the version of this fault that survives a replacement sensor, because the new one goes back onto the same bad mounting.

Likely causes

Start here

Impact sensor disturbed during body repair · moderate
Corroded or loose connector · easy
Corroded earth connection · moderate
Water ingress into connector · moderate

Less common

Damaged wiring harness · moderate
Faulty restraints control module · specialist

Symptoms

Components involved

Information, not instruction

CarGeek is a reference, not a service manual. Its pages are written from public sources and from what other people have found, never from a manufacturer's own service information, so they can be wrong or incomplete for your particular vehicle. Some of what they describe carries real risk: high voltage, fuel under pressure, stored energy, hot and moving parts.

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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What makes one worth reading:

The car — make, model, year and engine. The same fault behaves differently on each.
What you measured, not only what you replaced.
What actually fixed it — or that nothing did, which is worth knowing too.