Internal failure of the Occupant Detection Module (ODM) itself, such as a faulty circuit board or corrupted software.; Poor electrical connection at the ODM connector, including corrosion or loose pins.; Damaged wiring harness between the ODM and the airbag control module, causing signal interference.; Voltage supply issues to the ODM, such as a weak battery or faulty ground connection.; Water intrusion or physical damage to the ODM, often from spills or accidents.; Software glitch in the ODM requiring a reset or reprogramming.; Failed occupant weight sensor or seat mat that is integrated with the ODM, though this is less common for an internal fault code.

DTC codes / B00xx · Airbags, seats, doors, lights and comfort systems / B0099

B0099Occupant Detection Module Internal Fault

Q: What does code B0099 mean?

Occupant Detection Module Internal Fault. The B0099 code indicates that the Occupant Detection Module (ODM), which monitors the passenger seat to determine if an occupant is present and their size, has detected an internal fault within its own circuitry or software. The module's self-diagnostics have identified a failure that prevents it from reliably reporting occupant status to the airbag control module, potentially affecting passenger airbag deployment.

The B0099 code indicates that the Occupant Detection Module (ODM), which monitors the passenger seat to determine if an occupant is present and their size, has detected an internal fault within its own circuitry or software. The module's self-diagnostics have identified a failure that prevents it from reliably reporting occupant status to the airbag control module, potentially affecting passenger airbag deployment.

SystemBody

Code typeGeneric (all makes)

SeverityHigh

Fix difficultyProfessional

AreaAirbags, seats, doors, lights and comfort systems

Symptoms you may notice

The airbag warning light on the dashboard is illuminated, often with no other noticeable symptoms.
The passenger airbag status indicator may show 'off' or 'disabled' even when an adult is seated in the passenger seat.
The passenger airbag may be disabled entirely, increasing injury risk in a collision.
In some vehicles, a message such as 'Service Airbag System' or 'Occupant Sensor Fault' may appear on the driver information center.
Intermittent operation of the passenger airbag indicator, where it flickers or changes state without a passenger present.

Common causes, most likely first

Internal failure of the Occupant Detection Module (ODM) itself, such as a faulty circuit board or corrupted software.
Poor electrical connection at the ODM connector, including corrosion or loose pins.
Damaged wiring harness between the ODM and the airbag control module, causing signal interference.
Voltage supply issues to the ODM, such as a weak battery or faulty ground connection.
Water intrusion or physical damage to the ODM, often from spills or accidents.
Software glitch in the ODM requiring a reset or reprogramming.
Failed occupant weight sensor or seat mat that is integrated with the ODM, though this is less common for an internal fault code.

How to diagnose and fix it

Verify the code with a scan tool that can read body codes and check for related codes in the airbag system.
Inspect the ODM connector and wiring for corrosion, loose pins, or damage, and clean or repair as needed.
Check the battery voltage and ground connections to ensure the ODM receives stable power.
Perform a battery disconnect reset (capacitive discharge) to clear any temporary software glitch, then recheck the code.
If the code persists, follow the manufacturer's diagnostic flow chart, which may involve testing the ODM with a known-good unit or using a scan tool to perform calibration or reprogramming.
Replace the ODM if internal failure is confirmed, and perform any required initialization or calibration procedure with a scan tool.
Clear codes and verify the repair by cycling the ignition and confirming the airbag light is off and the passenger airbag indicator functions correctly.

ODM Internal Faults Often Misdiagnosed

A weak or failing battery can cause the ODM to set an internal fault code due to low voltage during startup, so always load-test the battery before condemning the module.
The ODM is often integrated with the passenger seat weight sensor mat, and a faulty mat can sometimes trigger an internal fault code, so inspect the seat wiring and mat for damage.
After replacing the ODM, some vehicles require reprogramming or calibration with a factory-level scan tool, and skipping this step will leave the airbag light on.
Water damage from spills or a leaking sunroof can corrode the ODM connectors and cause internal faults, so check for signs of moisture under the passenger seat.
This code does not always mean the ODM is defective; poor grounds or a chafed wiring harness can mimic an internal fault, so perform a thorough circuit test before replacement.

Can I keep driving with B0099?

It is not safe to continue driving with this code because the passenger airbag may be disabled, increasing the risk of serious injury in a crash. Have the vehicle diagnosed and repaired by a qualified technician before carrying passengers in the front seat.

Tools that help

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Guidance is general and written for all OBD-II vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.