A Citroën crash data reset clears the stored impact record from your original airbag ECU, so the module can work normally again and the airbag light can go out. It is done off the car, by post, and it is usually far cheaper than buying a replacement unit. Our standard airbag module reset costs £35 to £46, depending on the module, and we aim to turn most units around the same day when they arrive in the morning.
This guide explains what crash data is, when a reset is the right fix, what to check first, how the postal process works, what happens at the MOT and why a light sometimes stays on afterwards.
TL;DR
- Crash data is a lock-out record saved in the airbag ECU after an impact or deployment. A reset clears it and returns your original module.
- A reset does not replace damaged parts. Deployed airbags, seatbelt pretensioners and faulty sensors must be put right first.
- Our standard reset is £35 to £46. Motorhome modules are £65 and mobile airbag resets start from £75.
- An SRS warning light that stays on is a major MOT defect, so fix the cause before the test.
- Some C3, C4, DS3, DS4 and DS5 cars are subject to an airbag stop-drive recall. Check your VIN before anything else.
Table of Contents
- What crash data in a Citroën airbag ECU actually means
- Check these things before you reset anything
- Check for the airbag recall first
- How a postal Citroën reset works
- Common Citroën models we see
- What does a Citroën airbag reset cost?
- Will a reset get you through the MOT?
- Why the airbag light can stay on after a reset
- Our view on resetting Citroën modules
- Ready to send your Citroën module?
- Practical tips for a smooth reset
- FAQ
- Sources
What crash data in a Citroën airbag ECU actually means
Your airbag control unit (also called the SRS module or airbag ECU) watches signals from impact sensors, seat occupancy sensors and seatbelt switches. When it sees a crash-level event, it fires the airbags or pretensioners it needs to, then writes a record of the event into its memory.
That record is the crash data. The module treats it as a reason to stay locked: the airbag warning light comes on and the system will not arm again. The design is deliberate. A unit that has just been through a crash has no business being trusted without a check.
Two things follow from this:
- The lock is in the module's memory, not in the car's wiring. A generic OBD reader can often see the fault but cannot remove a stored crash record. The data has to be cleared at module level.
- The record can be there even if nothing deployed. A hard kerb strike, a shunt in a car park or a pothole impact can trigger a crash flag without any airbag opening. The light comes on and nothing visible is wrong.
A reset is the answer when the module itself is sound and only the stored event is keeping the system disabled. It is not the answer when the module has been physically damaged, water-soaked or has an internal hardware failure. We assess that when the unit arrives.
Check these things before you reset anything
Resetting clears memory. It does not repair the car. If the crash damaged anything in the restraint system and you reset only the module, the light may go out while a part of the system still cannot do its job. That is the one outcome to avoid.
Before you post a Citroën module, make sure the following have been dealt with:
- Deployed airbags and seatbelt pretensioners. Any device that fired must be replaced. A pretensioner is a one-shot part and does not recover.
- Impact sensors. Front crash sensors, side sensors and any that sat in the crush zone should be inspected and replaced if damaged or if the mounting bracket is bent.
- Wiring and connectors. Look for crushed or pinched looms and damaged clock springs or connectors under the steering wheel.
- Seat and occupancy sensors. If the seat belt buckle switch or the passenger occupancy mat was involved, they may need attention.
Trade guidance on collision repair is consistent on this. Repairer Driven News published a technical guide stressing that a scan before and after the repair is the way to avoid missing hidden damage such as tripped impact sensors or seatbelt pretensioners. The same document notes that an OEM-level scan tool can identify deployed devices, tripped sensors and latched crash codes. If your garage has not run a proper scan, ask for one.
It also says the repaired car needs a full road test and function checks, confirming that no warning lamps or messages return. That is the standard we would hold any reset job to as well.
Check for the airbag recall first
If you drive a C3, C4, DS3, DS4 or DS5, do one thing before spending money on a reset. Citroën has issued an urgent stop-drive recall for certain models because of an airbag-system fault. The Government's MOT special notice on the Citroën stop-drive recall tells owners to check whether a vehicle is affected using its VIN on Citroën's website.
A recall repair is a separate matter from crash data. If your car is on the list, follow the manufacturer's instructions, and treat any airbag work on that car with extra care. A reset service cannot fix an inflator recall. If you are unsure, speak to a Citroën dealer or your garage before you drive.
How a postal Citroën reset works
Postal resets sound slightly daunting the first time, but the process is simple. Here is how ours runs.
1. Identify the module
Every airbag ECU has a part number on its label, and that number is what we match to the right reset procedure. Citroën uses many different modules across the C1, C2, C3, C4, Berlingo, Dispatch, Relay and the DS range, and the same model can carry different units depending on year, trim and market. Send us the part number or a clear photo of the label. If you are not sure what you are looking at, we can help you identify the unit over WhatsApp or by phone.
2. Remove the module safely
Removing an airbag ECU means working around live restraint components, so it should be done by someone trained. Manufacturer service guidance, such as TRW's operating instructions, says restraint system work should be done by trained personnel, with the ignition off and at least one minute allowed for the system to discharge. Disconnect the battery as well, and handle the module without dropping it or applying force to the connector.
On many Citroëns the module sits under the centre console or beneath the front seats. Your garage will know where it is on your model. If you are a trade customer, you will already have your own routine.
3. Post it to us
Pack the module in a sturdy box with padding, include your name, phone number, vehicle registration and a note of the fault. Use a tracked service. We work from our workshop, and the postal service covers the whole of the UK.
4. Reset, test and return
We read the module, clear the stored crash data, test it and send it back. For most modules that reach us in the morning, we aim to complete the job the same day. Our guides page explains how this differs from a no-comms fault or an MOT-related fault.
5. Refit and check
Once it is back in the car, refit the module in the correct orientation and torque, reconnect the battery, switch the ignition on and watch the airbag light. It should go through its normal self-check and go out. Then scan the car, and road test it.
Because we return your original unit, there is no need to code a replacement to the car in most cases. That is a big reason resetting beats replacing: a second-hand module often brings coding problems, immobiliser pairing issues or the wrong part number for your trim.
Common Citroën models we see
The approach is the same across the range, but the module varies. These model pages give you an idea of what we handle:
If your model is not listed, it does not mean we cannot help. Send the part number and we will confirm.
What does a Citroën airbag reset cost?
The cost depends on what you are actually buying. In the UK you tend to see three routes after an accident:
| Route | What it involves | Our price |
|---|---|---|
| Crash data reset of your original module | Postal service, original unit returned | £35 to £46 |
| Motorhome module reset | Same process for motorhome-specific units | £65 |
| Mobile airbag reset | We come to you rather than you posting | From £75 |
Those are fixed prices, published on our pricing page. The range for the standard reset reflects the difference between standard and more complex modules. If we find a unit needs a repair beyond a data reset, we tell you before we go ahead.
The alternative is a replacement module from a dealer, which means a new part plus programming, or a used unit that may need coding. We do not quote for those, since we are in the business of avoiding unnecessary replacement. If you have a like-for-like written quote from another reset provider, we will price match it.
On the cost of the whole job, remember to include what sits outside the module: replacement airbags, pretensioners, sensors and labour. A reset is usually the cheapest line on the bill, but it only works once the physical parts are right.
Will a reset get you through the MOT?
The MOT checks whether the airbag system appears to work. It does not look at stored crash data as such, but it does care about the warning lamp. The official MOT inspection manual classifies an SRS warning lamp that indicates a system malfunction as a major defect, and a major defect is a fail.
So in practice:
- If your airbag light is on because of stored crash data, a successful reset removes the cause and the lamp should go out. You should then pass that part of the test.
- If the light is on because of a physical fault, the reset will not hold. The lamp will return and the car will fail.
- If you fit a reset module and the lamp stays off but the system is actually missing a deployed airbag or pretensioner, you have a safety problem even if the test does not catch it. Do not drive that way.
The MOT is a minimum check on the day. Think of the real test as whether the system will protect you in the next collision, and make sure the repair work backs that up.
Why the airbag light can stay on after a reset
It is uncommon, but it happens. If the light returns or never goes out, these are the usual reasons:
- A second fault is still present. Crash data was only one of the faults stored. A sensor, connector or pretensioner circuit may still be open or shorted.
- A part was not replaced. A used or deployed airbag, a buckle switch or a clock spring may be giving the module a resistance reading it does not accept.
- The module has been damaged. Water, a hard impact or heat can damage the module's internals. In that case it may need a repair rather than just a reset.
- A connector is loose or corroded. Check the module connector and the under-seat plugs. Pushing them in or cleaning them solves more faults than you would expect.
- The module is the wrong one. If a replacement unit was fitted earlier, it may not match your car.
After a reset, scan the car with a tool that reads the SRS system and note the codes. We have a longer explanation in our blog post on what to do when an airbag light won't clear, including the UK checks to run through.
Our view on resetting Citroën modules
We see the same story every week. A Citroën has had a minor knock, the airbag light has come on, and the owner has been told the module needs replacing for several hundred pounds. Often it does not. The original unit is perfectly sound and is simply holding a crash record.
Our approach is to reset the original module when it is safe to do so, and to say so plainly when it is not. Our technicians have more than 40 years of combined experience, and that is why we are comfortable telling you to fix the physical damage first. The reset is the last step, not the first.
That is also why we publish fixed prices, help you identify the module from a part number or photo, and match a genuine like-for-like quote. You should know what you are paying before you post anything, and you should not be paying for a part you do not need.
John
Ready to send your Citroën module?
If the stored crash data is the only thing keeping your airbag light on, a postal reset is the quickest and most affordable fix. Send us your part number or a photo of the label, and we will confirm the module and the price before you post it. Most units that arrive in the morning are completed the same day.
You can see the full price list on our airbag module reset page, or start from the Airbag Reset UK home page. Garages and workshops can ask about discounted trade accounts, and campervan owners can go straight to our motorhome airbag reset. If you would rather not remove the module yourself, our mobile airbag reset starts from £75.
Practical tips for a smooth reset
- Photograph the label before you remove the module. It saves a second trip to the car if we need to check a part number.
- Note the airbag warning behaviour. Does the light stay on constantly, flash, or come on after a few seconds? That helps us diagnose the module.
- Keep the connector clean and dry. Do not spray cleaner into it.
- Do not open the module. Opening it can damage it and delays the job.
- Disconnect the battery before you start and wait. Give the system time to discharge before you touch anything.
- Keep your fault code printout. If a scan has already been done, include it with the module.
FAQ
Can I clear Citroën crash data with a normal diagnostic tool?
Usually not. A standard scanner can read the fault and sometimes clear a simple code, but a stored crash record normally sits in the module's memory and survives that. It takes a module-level reset to remove it, which is why the unit is taken out and processed separately.
How long does a Citroën airbag reset take?
Once the module is with us, most are done the same day when they arrive in the morning. Add your own postage time each way and the time it takes to remove and refit the unit. Complex modules can take longer, and we will tell you if yours is one of them.
Is it safe to drive with the airbag light on?
The light means the system has detected a fault and may not deploy in a crash. Have it checked rather than waiting for the MOT. If your car is a C3, C4, DS3, DS4 or DS5, check the stop-drive recall for your VIN first, and follow the manufacturer's instruction if it applies.
Will I need to code the module to the car after the reset?
In most cases no, because you get your original module back. It keeps its own identity, so you refit it and check that the light goes out. A replacement or used unit is different and often needs coding, which is one reason a reset is simpler.
Sources
- MOT inspection manual: cars and passenger vehicles, section 7, other equipment (GOV.UK)
- MOT special notice 03-25: testing vehicles affected by the Citroën stop drive recall (GOV.UK)
- Air Bag systems estimates, diagnostics and repairs (Repairer Driven News)
- TRW EasyCheck operating instructions