B05A0

Code

Generic B — Body

Occupant Classification System Calibration Incomplete

Brand: Generic

Type: B — Body

Views: UK: 19 EN: 55 RU: 20

AI status

Completed

ready

Completed 100%

Page language: EN

Causes

Calibration procedure not performed after seat removal, replacement, or repair
Battery disconnected or replaced and calibration not re-run
Interrupted or failed calibration sequence (scan tool or procedural error)
Faulty occupant detection sensor mat or individual sensor elements
Damaged wiring or poor connector connections between sensor mat and OCS module
Corrosion or water/moisture ingress in seat/connector area

Symptoms

DTC B05A0 stored in SRS/airbag system
Passenger airbag status may show disabled or on the dash/in vehicle message
Vehicle may prevent completion of OCS calibration routine
Occupant detection readings show erratic or near-zero values for passenger seat
Possible warning light (SRS/airbag) present

What to check

Read and record all SRS/airbag and body control module codes with a capable scan tool
Verify OCS calibration state and available calibration routines with manufacturer scan tool
Visually inspect seat area, connectors, and wiring harness for damage, corrosion, or loose connectors
Check battery voltage and charging system health before attempting calibration (stable >12.4 V recommended)
Inspect sensor mat for physical damage, moisture, or compression debris
Observe live data for occupant sensor channels while applying known test loads (manufacturer-specified) to the seat

Signal parameters

OCS sensor mat raw channel values (per-sensor or zone weight readings)
Occupant Classification Module calibration status/flag
Passenger airbag enable/disable output/status
Seatbelt buckle switch state (passenger side)
Seat position/occupancy logical output
Battery/ignition voltage during calibration

Diagnostic algorithm

Retrieve and record all stored DTCs from SRS/airbag and related modules. Note freeze frame data if present.
Verify vehicle-specific calibration procedure and required tools/weights from manufacturer documentation or service manual.
Inspect physical condition of passenger seat, sensor mat, connectors and wiring. Repair any damaged wiring or connectors and clear corrosion or moisture.
Confirm stable battery/charging voltage. Charge or maintain battery to manufacturer-specified level before attempting calibration.
Using a capable factory or dealer-level scan tool, confirm OCS module reports 'calibration incomplete' or similar status and attempt the manufacturer calibration routine exactly as specified (use specified weight or fixture).
While performing calibration, monitor live sensor channel values to verify sensors respond and produce plausible weight readings. If readings remain erratic or zero, suspect sensor mat or wiring.
If calibration fails repeatedly and wiring/connectors are good, swap or bench-test sensor mat (if serviceable) or replace sensor mat per service procedures. Re-attempt calibration after replacement.
If sensor mat replacement does not resolve, consider OCS control module fault. Check for available software updates or module reprogramming. Replace module only after confirming sensors and wiring are good and calibration still fails.
After successful calibration, clear codes and verify system status. Confirm passenger airbag enable/disable logic and that no related DTCs return during a road test or functional checks per manufacturer guidance.
If intermittent or CAN/communication related faults are present, diagnose those networks (U-codes) before repeating calibration.

Likely causes

Service work removed/installed seat or seat components and calibration was not performed
Connector not fully seated after repair leaving module without valid calibration data
Sensor mat damaged (tears, compression, foam debris) preventing stable readings
Low battery/unstable voltage during calibration attempt corrupted stored calibration
Module software requires update or has lost calibration memory

Fault status

⚠️ Status

Occupant Classification System calibration incomplete — the OCS module does not have a valid calibration. Passenger airbag enable/disable logic may be inhibited until calibration is completed successfully.

🟡 Repair difficulty: Medium

⏱️ Diagnostic time: 1.0 - 2.5 hours