Code Definition

B0090 — Active switch circuit voltage out of range

System: Body  |  Type: Generic (OBD-II Standard)  |  Make: Generic

About B0090

B0090 is a generic (obd-ii standard) body diagnostic trouble code. It belongs to the B-prefix family of codes, which covers body, interior, airbag, or comfort-electronics faults.

When B0090 is stored, the module has detected a plausibility fault — the measured value is in the electrical range but is not consistent with expected operating behaviour.

Scanning & clearing: Body (B) codes are often stored in the body control module, airbag module, or climate module. A basic OBD-II tool usually will not read body codes — an enhanced or OEM-level scan tool is typically required.

Because B0090 is a generic OBD-II code, its base definition is shared across manufacturers. The specific diagnostic steps, reference values, and repair procedures can vary by vehicle, and the TaT Diagnostic Assistant includes verified procedures submitted by working technicians.

Code Information

The airbag control module (ACM) monitors an active switch input that reports the state of an SRS related switch back to the module, typically the passenger airbag deactivation (PAD) switch on vehicles equipped with a manual on and off key switch, or on some vehicles a seat belt or occupant classification switch. DTC B0090 sets when the voltage the ACM measures on this switch input is outside the expected range, meaning the input is stuck at supply voltage, stuck at ground, floating, or fluctuating in a way that cannot correspond to either valid switch state. The ACM uses this input to gate dep...

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