OBD-II trouble code
U0455: Invalid Data Received From Restraints Occupant Classification System Module
A module is receiving messages from the occupant classification system (OCS) module, but the data inside them is implausible or out of range. The link is alive; the content is wrong. Because this module decides whether the passenger airbag is enabled or suppressed, treat it as safety-critical and diagnose it promptly.
Quick facts
- System
- Network
- Category
- Network Communication
- Severity
- High severity
- Drivable
- Usually safe to drive short-term
- Repair cost range
- $100 – $1,100
- DIY difficulty
- Shop recommended
What does U0455 mean?
The restraints occupant classification system (OCS) module — sometimes called the occupant detection or passenger presence module — determines who or what is in the front passenger seat. Using seat-mounted weight/pressure sensors or a bladder-and-sensor system, it classifies the occupant as empty, a small person (such as a child), or a normal-size adult, and passes that classification to the restraints control module so the system can enable or suppress the passenger airbag accordingly. This is what drives the 'PASSENGER AIRBAG OFF/ON' indicator. U0455 sets when a receiving module is still hearing from the OCS module, but the data in its messages is invalid — a value is out of range, implausible, or contradicts what other modules see. The link is alive; the content simply can't be trusted, which is the defining difference from a lost-communication code (such as U0154), where the module has gone completely silent.
Because occupant classification governs passenger airbag suppression, an invalid-data fault here is safety-relevant. When the OCS data can't be trusted, the system may default the passenger airbag to a fixed state and illuminate the airbag/SRS warning light — meaning the passenger airbag could fire when it should be suppressed, or stay suppressed when it should deploy. Common causes cluster around whatever corrupts the module's data or its link: seat-sensor and seat-harness problems are especially common here because the sensors live under a seat that slides, folds, and gets stepped on; low system voltage or a poor ground; corroded or damaged connectors under the seat, where spilled liquids are a documented cause; chafed bus wiring; and software or configuration problems after service. An OCS system frequently needs a calibration or 'zero/rezero' procedure after a seat, seat cover, or module is replaced — skipping that step is a very common source of invalid-data and classification faults.
Symptoms center on the airbag/SRS warning light, a 'PASSENGER AIRBAG OFF' light that behaves incorrectly (stuck on with an adult seated, or off with the seat empty), and sometimes companion restraints codes. The car will start and drive normally, but the passenger-side occupant protection logic may be compromised. Treat U0455 as a prompt-repair item. Basic checks of the battery, grounds, and under-seat connectors are reasonable, but OCS calibration and any airbag-circuit work should be done by a technician with the correct scan tool and service data.
Common causes
- OCS not calibrated/rezeroed after a seat, seat cover, sensor, or module replacement
- Faulty or damaged seat occupant sensor or seat sensor mat/bladder
- Corroded, loose, or damaged under-seat connectors and seat harness
- Spilled liquids or moisture reaching the under-seat sensors or connectors
- Low system voltage, a weak battery, or a poor ground
- Chafed or damaged bus wiring corrupting messages in transit
- Outdated, corrupted, or mismatched module software after an update
- Internal occupant classification module fault
Symptoms
- Airbag/SRS warning light on, often with an 'airbag service required' message
- 'PASSENGER AIRBAG OFF/ON' indicator behaving incorrectly
- Passenger airbag defaulted to a fixed enabled or suppressed state
- Companion restraints or network-communication codes stored alongside U0455
- Fault often triggered right after seat work, a spill, or heavy loading of the seat
Diagnostic steps
- 1.Read ALL stored codes, including restraints/SRS and OCS-specific codes, with a scan tool that can access the airbag system.
- 2.Confirm whether the seat, seat cover, occupant sensor, or module was recently serviced — a missing calibration/rezero is a leading cause of invalid data.
- 3.Inspect the under-seat connectors and seat harness for corrosion, damage, loose pins, and evidence of liquid intrusion.
- 4.Check the occupant sensor/mat and its wiring for damage from seat movement or foot traffic.
- 5.Load-test the battery and verify charging voltage and the module's grounds.
- 6.Perform the manufacturer's OCS calibration/zeroing procedure if indicated.
- 7.Follow the manufacturer's safety procedure before any hands-on airbag work, and refer to a qualified technician if unsure.
Repair cost
$100 – $1,100
Cost depends on the cause. An OCS calibration/rezero or reprogramming is often $100-$300 when that resolves it. Repairing an under-seat connector, seat harness, or ground is typically $150-$450. A failed seat occupant sensor or sensor mat runs roughly $200-$700 depending on the vehicle and whether the seat must be partly disassembled. Occupant classification module replacement with programming is the expensive case at roughly $400-$1,100. Because this is a safety system, prioritize a correct diagnosis over the cheapest fix.
Estimate your repair
Run the numbers for your vehicle
Open the Repair Cost Estimator with module communication / can bus diagnosis preselected. Adjust labor rate and vehicle category to fit your situation.
DIY vs shop
Leave this one to a qualified shop. It typically involves emissions-critical components, refrigerant handling, or other work that requires manufacturer-grade tooling, training, or certification. DIY attempts often produce a more expensive problem than the original code.