B0196

Code

Generic B — Body

Airbag System Fault - Sensor/Communication

Brand: Generic

Type: B — Body

Views: UK: 6 EN: 4 RU: 1

AI status

Completed

ready

Completed 100%

Page language: EN

Causes

Faulty SRS impact sensor or occupant sensor
Damaged or corroded wiring or connector between sensor and airbag control module
Open or shorted squib (airbag) circuit or seatbelt pretensioner circuit
Loss of power or ground to the airbag control module or sensor
Intermittent or failed CAN/LIN/serial communication on the vehicle data bus
Faulty airbag control module (ACM)/SRS module

Symptoms

SRS/Airbag warning light illuminated on the dash
Possible companion safety lights (seatbelt pretensioner) on
Vehicle may disable one or more airbags or pretensioners
Crash data or airbag deployed flag stored in module
Intermittent light that returns after driving or connector movement

What to check

Read full SRS code list and freeze frame with a capable scan tool
Confirm module software/version and check for stored crash/deployment flags
Visually inspect connectors and wiring for corrosion, damage, or chafing (under seats, B-pillars, dash)
Check battery voltage and ground integrity at the airbag control module
Wiggle-test connectors and wiring while monitoring live data for fault flicker
Compare sensor live-data values to known-good values or manufacturer specifications

Signal parameters

Airbag control module supply voltage: stable 12 V (check during cranking and at key ON)
Module ground: low resistance to chassis ground
Squib/pretensioner circuit resistance: typically very low (manufacturer-specific; often
Occupant/sensor signal voltages or CAN message rate and content (compare live sensor messages to expected values)
CAN bus idle level ~2.5 V per line (differential behavior during activity); watch for missing or corrupted packets
Fault counters or checksum error rates reported by the SRS module

Diagnostic algorithm

Follow manufacturer SRS safety procedures before any work (disable battery and wait required time; use insulated tools; avoid static).
Use a compatible scan tool to read and record all SRS codes and live data. Note any U-codes (communication) or crash flags.
Inspect connectors, harnesses, and grounding points for the sensor circuits referenced by the code. Repair any physical damage.
With battery reconnected per safe procedure, monitor live sensor data while gently moving wires/connectors to reproduce the fault; isolate intermittent connector issues.
Check supply voltage and ground at the airbag control module and at the affected sensor(s). Repair poor power/ground paths.
If the fault indicates communication errors, inspect CAN/LIN bus wiring and related modules. Use a scope or CAN tester to verify bus activity and signal integrity.
Measure squib and sensor resistances only following the manufacturer’s prescribed procedure (many systems require module power-down before measuring). Compare to spec.
If a sensor or wiring fault is confirmed, repair or replace the faulty component. Clear codes and perform required system resets or calibrations.
If module replacement is required, ensure correct programming/coding and clear crash/deployment data per manufacturer instructions.
Re-check the system for stored codes and confirm the SRS lamp extinguishes and that no new codes appear after test drive.

Likely causes

Connector corrosion or loose pin at an SRS sensor (under seats or in B-pillar)
Damaged harness due to seat movement, seat track, or previous repairs
Failed sensor (rear/front impact or occupant classification sensor)
CAN bus wiring short or high resistance causing packet errors
Battery disconnect or low supply voltage causing module faults

Fault status

⚠️ Status

SRS fault indicating a sensor or communication problem. The airbag control module has detected invalid, missing, or out-of-range data from an SRS sensor or a bus communication issue. The system may disable related airbags until the cause is fixed.

🟡 Repair difficulty: Medium

⏱️ Diagnostic time: 1-3 hours