U0455: Invalid Data Received From Restraints Occupant Classification System Module
What to do
This is the system that works out who is in the passenger seat and decides whether the passenger airbag should go off, and at what force.
Most often the fault shows as the passenger airbag off light staying on with a grown adult sitting there. That means they are travelling without a front airbag, and it needs sorting — but it is the system failing safely.
Before spending anything, do this, because it is free and it fixes a good proportion of these. Take everything out from under the passenger seat — bags, bottles, tools, the jack. Take off any seat cover or cushion. Make sure no floor mat is trapped under the seat rails. Then sit in the seat normally and see whether the light behaves. Anything pressing on the seat from above or below corrupts the reading, and that is far commoner than a failed part.
Two things worth telling a garage. If the passenger seat has been unbolted for any reason — carpets dried out, wiring done, the seat taken out to carry something — the system has to be re-zeroed afterwards, and that step gets skipped constantly. And if a child seat is normally fitted there, say so: on some cars a tightly belted child seat loads the mat far beyond the child's weight.
Until it is fixed, carry an adult passenger in the back if you have the choice, and never fit a rear-facing child seat in the front while the airbag's status is uncertain.
What this code means
The occupant classification module is broadcasting data that cannot be accepted as true. See U0452 for the restraints system's framing and safety rules.
This is the system that decides who is sitting in the passenger seat, and it exists because an airbag sized for an adult is dangerous to a child. A sensing mat, a fluid-filled bladder or a set of strain gauges in the seat frame measures the load in the seat, and the module classifies it: empty, a child or child restraint, a small occupant, an adult. The passenger airbag is then enabled, disabled, or deployed at reduced force accordingly — which is what the passenger airbag off lamp on the dashboard is reporting when it lights.
Invalid data here fails in two directions and they are not equally visible.
The safe direction, and the common one, is that the system disables the passenger airbag. The lamp stays on with a full-sized adult in the seat. That is a fault, and it means an occupant is travelling without a front airbag — but the system has failed the right way.
The other direction is the one that justifies this page. A classification that overstates a small occupant, or a system reporting a plausible-but-wrong figure, leaves the airbag deploying at a force chosen for somebody who is not there. That is not visible from the dashboard at all.
The causes are overwhelmingly physical and mostly innocent, which is why this is worth checking before anything is replaced.
- Something under the seat. A bag, a jack, a bottle or a tool wedged under the seat frame loads it from below and corrupts the reading.
- Something on the seat. A heavy aftermarket seat cover, a cushion, or a taut cover pulling across the sensing mat.
- A floor mat trapped under the rails, which does the same thing more subtly.
- The seat unbolted and refitted. Carpet drying, wiring work, or removal to carry something — the system must be re-zeroed after almost any work on that seat, and that step is skipped constantly.
- A child seat belted in tightly, which on some vehicles loads the sensing mat well beyond the child's weight.
So there is a free check worth doing first: empty the seat and the space under it completely, remove any cover, sit in the seat normally, and watch the lamp. If it behaves, the fault was what was in the car rather than what is wrong with it.
Likely causes
Start here
- Object or fitting under the seat loading the sensor · easy
- Occupant classification system not recalibrated · specialist
- Damaged wiring under the front seats · moderate
- Corroded or loose connector · easy
Less common
- Faulty restraints control module · specialist
- Damaged data bus wiring · moderate
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.
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