Symptom
Airbag warning light illuminated
The airbag or SRS warning is lit, usually a seated figure with a circle in front of it. It means the system has switched itself off, so the airbags and seatbelt pretensioners may not work in a crash — the safe direction, since a bag firing when it should not is worse, but the protection is absent while the car drives perfectly normally. A roadworthiness test failure in most jurisdictions. Not something to investigate at home: airbags are pyrotechnic devices and disturbing the wiring with the battery connected can deploy one. The commonest cause is the connectors under the front seats, disturbed by seat adjustment or cleaning underneath.
Also described as: srs light, airbag light, srs warning, air bag light on, restraint warning, چراغ ایربگ روشن شد, چراغ ایربگ, ایربگ روشن, luz airbag, testigo airbag encendido, luz bolsa aire, لمبة الإيرباق, لمبة الإيرباق مضيية, لمبة الوسادة الهوائية, علامة الإيرباق مضيئة, إشارة كيس الهواء
What this usually means
The system has switched itself off, so the airbags and pretensioners may not fire in a crash while the car drives entirely normally. That gap between how the car feels and what has actually been lost is the whole reason this lamp gets postponed, and it is worth naming to anybody who asks.
Two causes dominate and both are connections rather than components. The connectors under the front seats are the commonest — they are disturbed by seat adjustment, by cleaning underneath, and by anything slid under the seat, and their contacts are deliberately designed to be sensitive so that a marginal connection is reported rather than tolerated. The clock spring is the other, and Japanese workshop references identify it as the leading cause: it is the flat ribbon cable that carries power to the driver's airbag through a steering wheel that turns, and after enough thousands of turns its conductors fatigue and break. It commonly announces itself alongside horn or steering-wheel-control faults, because they share the same ribbon.
The passenger seat's occupant sensing mat is the third, and Japanese sources note the specific way it fails: heavy loads left on the seat for long periods, or strong pressure on the cushion, damage the sensing element. That produces its own separate lamp on many cars.
Do not investigate this at home. Airbags are pyrotechnic devices, and disturbing the wiring with the battery connected can deploy one — into the face of whoever is leaning over it. The standard workshop practice is to disconnect the battery and wait for the system's reserve capacitor to discharge before touching any airbag circuit.
An illuminated lamp is a roadworthiness test failure in most jurisdictions, which is often what finally prompts the repair.
Working through it
| What you find | Likely cause | How to confirm it | What fixes it |
|---|---|---|---|
| Lamp came on after seat adjustment, cleaning under the seats, or carrying something | A connector under the front seat disturbed — the commonest cause by a wide margin | Read airbag module codes, which name the circuit. Inspect the under-seat connectors for security and corrosion — with the battery disconnected and the reserve discharged. | Reseat or renew the connector. Clear the code and confirm it does not return after a drive. |
| Lamp with horn or steering-wheel buttons also not working | Clock spring — the ribbon cable through the steering column has fatigued and broken a conductor | The coincidence is the confirmation, because those circuits share the ribbon. Codes will name the driver's airbag circuit as open. | Renew the clock spring. Centre it correctly on refitting; a mis-centred one fails again quickly and can affect steering angle sensing. |
| Lamp appeared after the seat was unbolted or the interior worked on | A connection not remade, or the occupant sensing system not re-zeroed after the seat was removed | Retrace the work. Ask specifically whether the seat came out — the re-zero step is skipped constantly. | Remake the connection and run the manufacturer's re-zero or calibration procedure. |
| Passenger-side fault codes, heavy items usually left on that seat | The occupant sensing mat damaged by sustained load or strong pressure on the cushion | Empty the seat completely and re-test. Read the occupant classification module's own codes rather than the general airbag ones. | Renew the sensing mat or seat cushion assembly, then re-zero the system. |
| Lamp on a car with a known history of a crash | Crash data stored in the module, which many modules latch permanently after deployment | Read the module for crash data as well as current faults. A module that has recorded a deployment will not clear on a code reset. | Replace or reset the module by the manufacturer's approved route. Be aware this is exactly the fault a badly repaired car conceals. |
| Lamp flickers over bumps or with a particular seat position | An intermittent connection rather than a failed component — a chafed harness under the seat or in the door pillar | Read for intermittent codes and inspect the harness where it flexes. Reproduce by moving the seat through its travel with the ignition on. | Repair the chafed harness and secure it clear of the mechanism. An intermittent here is as serious as a permanent fault. |
-
Lamp came on after seat adjustment, cleaning under the seats, or carrying something
- Likely cause
- A connector under the front seat disturbed — the commonest cause by a wide margin
- How to confirm it
- Read airbag module codes, which name the circuit. Inspect the under-seat connectors for security and corrosion — with the battery disconnected and the reserve discharged.
- What fixes it
- Reseat or renew the connector. Clear the code and confirm it does not return after a drive.
-
Lamp with horn or steering-wheel buttons also not working
- Likely cause
- Clock spring — the ribbon cable through the steering column has fatigued and broken a conductor
- How to confirm it
- The coincidence is the confirmation, because those circuits share the ribbon. Codes will name the driver's airbag circuit as open.
- What fixes it
- Renew the clock spring. Centre it correctly on refitting; a mis-centred one fails again quickly and can affect steering angle sensing.
-
Lamp appeared after the seat was unbolted or the interior worked on
- Likely cause
- A connection not remade, or the occupant sensing system not re-zeroed after the seat was removed
- How to confirm it
- Retrace the work. Ask specifically whether the seat came out — the re-zero step is skipped constantly.
- What fixes it
- Remake the connection and run the manufacturer's re-zero or calibration procedure.
-
Passenger-side fault codes, heavy items usually left on that seat
- Likely cause
- The occupant sensing mat damaged by sustained load or strong pressure on the cushion
- How to confirm it
- Empty the seat completely and re-test. Read the occupant classification module's own codes rather than the general airbag ones.
- What fixes it
- Renew the sensing mat or seat cushion assembly, then re-zero the system.
-
Lamp on a car with a known history of a crash
- Likely cause
- Crash data stored in the module, which many modules latch permanently after deployment
- How to confirm it
- Read the module for crash data as well as current faults. A module that has recorded a deployment will not clear on a code reset.
- What fixes it
- Replace or reset the module by the manufacturer's approved route. Be aware this is exactly the fault a badly repaired car conceals.
-
Lamp flickers over bumps or with a particular seat position
- Likely cause
- An intermittent connection rather than a failed component — a chafed harness under the seat or in the door pillar
- How to confirm it
- Read for intermittent codes and inspect the harness where it flexes. Reproduce by moving the seat through its travel with the ignition on.
- What fixes it
- Repair the chafed harness and secure it clear of the mechanism. An intermittent here is as serious as a permanent fault.
Codes that produce this symptom (178)
Listed with the codes that most typically present this way first — the likeliest place to start.
- B0001 Driver Frontal Stage 1 Deployment Control Typical of this code High
- B0002 Driver Frontal Stage 2 Deployment Control Typical of this code High
- B0003 Driver Frontal Stage 3 Deployment Control Typical of this code High
- B0004 Driver Knee Bolster Deployment Control Typical of this code High
- B0005 Collapsible Steering Column Deployment Control Typical of this code High
- B0010 Passenger Frontal Stage 1 Deployment Control Typical of this code High
- B0011 Passenger Frontal Stage 2 Deployment Control Typical of this code High
- B0012 Passenger Frontal Stage 3 Deployment Control Typical of this code High
- B0013 Passenger Knee Bolster Deployment Control Typical of this code High
- B0020 Left Side Airbag Deployment Control Typical of this code High
- B0021 Left Curtain Deployment Control 1 Typical of this code High
- B0022 Left Curtain Deployment Control 2 Typical of this code High
- B0028 Right Side Airbag Deployment Control Typical of this code High
- B0029 Right Curtain Deployment Control 1 Typical of this code High
- B002A Right Curtain Deployment Control 2 Typical of this code High
- B0030 Second Row Left Side Airbag Deployment Control Typical of this code High
- B0031 Second Row Left Frontal Stage 1 Deployment Control Typical of this code High
- B0032 Second Row Left Frontal Stage 2 Deployment Control Typical of this code High
- B0033 Second Row Left Frontal Stage 3 Deployment Control Typical of this code High
- B0038 Second Row Right Side Airbag Deployment Control Typical of this code High
- B0039 Second Row Right Frontal Stage 1 Deployment Control Typical of this code High
- B003A Second Row Right Frontal Stage 2 Deployment Control Typical of this code High
- B003B Second Row Right Frontal Stage 3 Deployment Control Typical of this code High
- B0040 Third Row Left Side Airbag Deployment Control Typical of this code High
- B0041 Third Row Left Frontal Stage 1 Deployment Control Typical of this code High
Information, not instruction
CarGeek is a reference, not a service manual. Its pages are written from public sources and from what other people have found, never from a manufacturer's own service information, so they can be wrong or incomplete for your particular vehicle. Some of what they describe carries real risk: high voltage, fuel under pressure, stored energy, hot and moving parts.
Have anything you intend to act on checked by a trained person against the manufacturer's own procedure for your vehicle. Nothing here replaces that procedure.
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