Can You Reset an Airbag Control Module?
Can an airbag control unit be reset?
Yes, an airbag control unit can be reset after an accident – but not with standard diagnostic software. The stored crash data is located in the EEPROM memory of the control unit and can only be deleted by specialized service centers. Airbag24 offers this service for all makes and models.
After an accident, the airbag control unit stores so-called crash data in its internal memory (EEPROM). This data documents the impact and locks the control unit – the airbag warning light stays on continuously and the entire restraint system is deactivated. The control unit only functions normally again after these data are professionally deleted.
What is crash data in the control unit?
Crash data are digital records of an accident that the control unit stores in non-volatile EEPROM memory. They contain information about the time of impact, the severity of the crash, and which airbags/seat belt tensioners were triggered. This data remains permanently stored even after the battery is disconnected.
| Stored Information | Description | Purpose |
|---|---|---|
| Crash event flag | Marking that an accident occurred | Locks the control unit |
| Impact direction | Front, side, rear, or combination | Documentation of the accident sequence |
| Crash severity | Measured deceleration values | Determination of impact intensity |
| Triggered components | Which airbags/seat belt tensioners were fired | Documentation of deployment |
| Error codes | Associated DTCs (Diagnostic Trouble Codes) | Diagnostic information |
Why doesn't a standard reset work?
Standard OBD-2 diagnostic devices and software such as VCDS or VCP can read error codes in the airbag control unit and partially delete them – however, the actual crash data in the EEPROM is not accessible with standard diagnostic software. The memory area is deliberately protected by the manufacturer.
| Method | Delete error codes? | Delete crash data? |
|---|---|---|
| OBD-2 standard scanner | Partially | No |
| VCDS / VCP (VAG) | Yes | No (only on a few models) |
| Manufacturer diagnostics (ODIS, ISTA, etc.) | Yes | Only on some control units |
| Specialized service center (EEPROM) | Yes | Yes – completely |
The difference: Error codes vs. crash data
Error codes (DTCs) are volatile diagnostic information that any diagnostic device can delete. Crash data, on the other hand, are permanently stored in the EEPROM and are deliberately not made accessible through the standard diagnostic interface. A deleted error code returns immediately as long as the crash data is still in memory.
How does professional reset work?
During a professional reset, the control unit is removed and the EEPROM memory chip is read and written directly. The crash data is selectively deleted while all other vehicle-specific data (coding, calibration) are preserved. After that, the control unit functions exactly as it did before the accident.
- Remove control unit: Workshop removes the control unit from the vehicle
- Send in: Send the control unit to the repair shop (or bring it yourself)
- Read EEPROM: Memory chip is read directly
- Identify crash data: Affected memory areas are located
- Delete data: Crash event, error codes, and trigger flags are removed
- Testing: Control unit is tested for full functionality
- Return shipment: Repaired control unit is sent back
- Installation: Workshop reinstalls the control unit, warning light goes out
When is a reset possible – and when not?
A reset is possible if the control unit itself is undamaged and only has crash data stored. A reset is not possible if the control unit is internally damaged (e.g., by water or destroyed electronics) or if internal sensors have been triggered that only function once.
| Situation | Reset possible? | Solution |
|---|---|---|
| Crash data stored, hardware OK | Yes | EEPROM reset at Airbag24 |
| Minor accident, no deployment | Yes | Delete crash data, clear error memory |
| Internal acceleration sensor triggered | Model-dependent | Inspection required – possibly replacement |
| Water damage / corrosion | Conditional | Electronics repair + reset |
| Control unit mechanically destroyed | No | New control unit required |
Can I reset the control unit myself?
Self-resetting is not possible with standard workshop equipment. While there are cheap "reset tools" available on the internet, these only work on a few control unit types and can render the control unit unusable if applied incorrectly. We strongly advise against it.
Various airbag reset tools are offered on the internet that promise simple resetting. However, the risks are considerable:
- Incorrect application: Can permanently damage the EEPROM
- Incomplete reset: Not all crash flags are deleted
- Safety risk: An incorrectly reset control unit can cause false deployments
- Liability: In the event of another accident, insurance problems can arise
Reset airbag control unit at Airbag24
Airbag24 professionally resets airbag control units of all makes and models. Crash data is completely deleted, functionality is tested, and you get your control unit back within 3-4 business days – TÜV-safe and with savings of up to 50% compared to a new part.
- All makes: VW, Audi, BMW, Mercedes, Opel, Ford, Seat, Skoda, and many more
- Delete crash data: Complete EEPROM reset
- Electronics repair: Also for internal defects
- Fast processing: 3-4 business days (express available on request)
- Cost savings: Up to 50% cheaper than new part
- 20+ years of experience: Over 20,000 repaired control units
Frequently asked questions about resetting the airbag control unit
Here you will find answers to the most important questions about resetting the airbag control unit.
Is it enough to clear the error memory?
No, clearing the error memory via OBD-2 only removes the diagnostic codes, not the actual crash data in the EEPROM. The warning light returns immediately because the control unit recognizes the stored crash data again during the next self-test and sets the error anew.
Does the control unit need to be removed for reset?
In most cases, yes – the EEPROM reset requires direct access to the control unit's circuit board. On a few models (mainly with Bosch control units), crash data can also be deleted via the OBD interface, but this is the exception.
Does the control unit work normally again after reset?
Yes, after a professional reset, the control unit works exactly as it did before the accident. All vehicle-specific data (VIN coding, sensor calibration) are preserved. The airbag warning light goes out after installation and the system is fully functional again.
Is a reset possible after every accident?
A reset is possible after almost all accidents as long as the control unit itself is undamaged. Even after multiple accidents, the same control unit can be reset. Only if the electronics are physically damaged (water, mechanical destruction) is replacement required – Airbag24 can help here too.