B06A3

Code

Generic B — Body

Occupant Classification System Fault

Brand: Generic

Type: B — Body

Views: UK: 4 EN: 4 RU: 2

AI status

Completed

ready

Completed 100%

Page language: EN

Causes

Damaged or shorted occupant detection mat (seat sensor pad)
Open or short in sensor wiring or poor connector contact (moisture/corrosion)
Faulty OCS control module or seat control unit
Loss of power or ground to the OCS module
CAN bus or LIN communication fault between OCS and airbag/SRS module
Incorrect module software or calibration needed after seat replacement

Symptoms

SRS / airbag warning light illuminated on dash
Passenger airbag indicator incorrectly showing disabled/enabled
Passenger airbag not arming when occupied (or arming incorrectly)
DTC stored in OCS or SRS module with possible related communication codes
Intermittent or persistent fault after seat movement

What to check

Scan SRS and OCS modules with a capable scan tool; read and record all codes and freeze frame data
Verify battery voltage is within normal range (11–14.5 V) with key on
Visually inspect seat area for signs of liquid, corrosion, or physical damage
Check connectors under the seat are fully seated and locking tabs intact
Wiggle test wiring harness while watching live data for changes
Check for related bus communication codes (U-codes) that indicate network issues

Signal parameters

OCS mat element resistance or impedance (manufacturer-specific ohms range)
Seat occupancy voltage or sensor voltage range (0–5 V typical for some systems)
OCS module supply voltage (B+ with ignition on)
Ground integrity (low resistance to chassis ground)
OCS status bits on CAN: occupant present/absent, weight classification, self-test status
Short-to-ground or short-to-voltage indications on sensor channels

Diagnostic algorithm

Safety first: follow vehicle manufacturer SRS service procedures — disable SRS system or disconnect battery as required before disconnecting connectors or performing repairs.
Scan and record all stored codes from SRS and OCS modules. Note freeze frame or PID values showing sensor readings at time of fault.
Visually inspect the seat and occupant sensor mat for damage, stains, or foreign objects. Inspect wiring routing under the seat and seat track areas for pinched/damaged wires.
Verify power and ground to the OCS module: measure B+ at the module with ignition on and check ground resistance to chassis.
With a scan tool capable of OCS diagnostics, view live sensor data and run any built-in self-tests or sensor resistive checks. Wiggle harness/connectors while monitoring for changes.
If a specific sensor channel shows open/short or out-of-range resistance, disconnect the mat and measure continuity/resistance of the mat per service data. Replace mat if out of spec.
If wiring is suspected, test continuity between mat connector and OCS module connector, checking for shorts to chassis or battery voltage.
If communication errors are present, check CAN/LIN bus voltages, termination, and related module communications. Repair any bus faults before replacing OCS module.
If module or mat is replaced, perform required calibration/learn procedure for the OCS per manufacturer instructions and then clear codes. Re-check for reappearance of B06A3.
If fault persists after wiring and sensor checks, consider replacement of the OCS control module and repeat calibration; retest thoroughly.

Likely causes

Poor connector contacts or damaged wiring under the seat (most common)
Faulty or degraded occupant detection mat/sensor pad
Module fault or intermittent communication on vehicle bus
Recent seat removal or service without OCS recalibration

Fault status

⚠️ Status

Occupant Classification System fault — SRS warning lamp may be illuminated; passenger airbag enable/disable may be incorrect. Diagnostic trouble code B06A3 stored in OCS/SRS module.

🟡 Repair difficulty: Medium

⏱️ Diagnostic time: 1-3 hours