Expect to pay roughly £50 to £100 for a professional airbag diagnostic at an independent garage, £120 to £200 at a main dealer, or £60 to £90 for a mobile visit. An illuminated SRS warning light is a Major MOT defect, so book a full SRS diagnostic promptly rather than driving on hoping it clears itself.
TL;DR:
- Most diagnostics cost between £50 and £100 at independents, £120 to £200 at main dealers, and £60 to £90 for mobile services, with comprehensive SRS checks requiring specialized equipment.
- Proper SRS diagnostics involve connecting professional scan tools to retrieve detailed fault codes, inspecting wiring and sensors, and sometimes bench testing the airbag module itself.
- Variations in quotes mainly depend on regional labor rates, vehicle make and model, depth of scan, and whether a reprogramming or parts replacement is necessary.
- Repair costs for airbag faults average around £92 for simple repairs, but can reach several hundred pounds if parts like clock springs or wiring looms need replacing after a crash.
- Driving or passing an MOT with an illuminated airbag warning light is illegal and results in an automatic fail; diagnostic and repair should be done promptly for safety and compliance.
Table of Contents
- How much does an airbag diagnostic fee actually cost?
- What does a proper SRS diagnostic actually involve?
- What makes one quote higher than another?
- What usually causes an airbag warning light, and what does it cost to fix?
- Can you drive or pass an MOT with the airbag light on?
- How do you choose a garage for an airbag diagnostic?
- Prioritising safety over short-term savings
- Airbag Reset UK: a straightforward postal reset for crash-data faults
- Sources
- FAQ
How much does an airbag diagnostic fee actually cost?
Prices swing more than most drivers expect, largely because "diagnostic" means different things depending on who is doing the work. An independent garage typically charges £50 to £100 for an initial professional scan, though that figure assumes a genuine SRS-capable tool rather than a basic engine-code reader.
Main dealers sit higher, usually £120 to £200. That premium isn't padding. Dealers carry manufacturer-specific software licences, ongoing training costs, and equipment tied to a single brand, and all of that gets baked into the hourly rate.
Mobile mechanics land in between, commonly £60 to £90, trading a bit of scope for the convenience of not having to book your car into a workshop. The catch is that a mobile technician may not carry every piece of kit a fixed workshop has on the bench, so a fault that needs deeper module testing might get referred on anyway.
A few things worth knowing before you book:
- A "basic" scan (engine codes only) is cheaper but won't touch SRS faults at all.
- A full multi-ECU diagnostic often runs £80 to £150 or more, because it checks several systems, not just one.
- Many garages will deduct the diagnostic fee from your final bill if you go ahead with the repair there, so it's always worth asking before you pay.
- Regional labour rates matter. City workshops with higher overheads generally charge more than rural ones for identical work.
What does a proper SRS diagnostic actually involve?
A cheap high-street code reader plugs into the OBD-II port and pulls generic engine fault codes. That's it. Consumer-grade scanners typically can't reach SRS or airbag modules at all, because manufacturers lock that data behind proprietary protocols. A genuine airbag diagnosis needs professional-grade equipment, and sometimes maker-specific software, to talk to the right modules.
A competent technician working through an SRS fault usually follows a similar sequence:
- Connect a professional scan tool and pull every stored and pending fault code from the airbag ECU, not just the engine ECU.
- Check live data from seatbelt pretensioners and occupancy or weight sensors under the front seats.
- Physically inspect wiring looms and connectors, particularly under seats and around the steering column, for corrosion or chafing.
- Bench test the airbag module itself if the fault won't clear or the ECU shows signs of internal failure.
Pro Tip: Ask the garage to print or email the fault codes alongside their findings. If the module later needs a crash-data reset rather than replacement, that code list saves you repeating the diagnostic elsewhere.
What makes one quote higher than another?
Two garages can look at the same airbag light and quote wildly different figures, and it usually comes down to a handful of variables rather than one garage simply overcharging.
- Labour rates and location. A workshop in central London or Manchester will typically charge more per hour than a rural garage, purely on overheads.
- Make and model. Some manufacturers require specialist tooling or licensed software that ordinary independents don't carry, pushing you towards a dealer or a specialist, especially for tasks like ADAS calibration: essential for your vehicle's safety and performance.
- Parts or reprogramming. If the fault needs a new sensor or a reprogrammed module, that adds cost on top of the diagnostic fee itself.
- Depth of scan. A quick code read costs less than a full SRS/multi-ECU check, but it also tells you less.
- Garage policy. Some deduct the diagnostic charge from the repair invoice if you proceed; others treat it as a separate, non-refundable fee.
Always ask which of these apply before you agree to a price over the phone.
What usually causes an airbag warning light, and what does it cost to fix?
Once the diagnostic identifies the fault, repair costs vary hugely depending on what's actually wrong. Marketplace data puts the average airbag-warning-light repair at around £92, with full airbag repairs averaging closer to £137, though your make and model will push that up or down.
The usual suspects:
- Clock spring failure. This coiled cable sits behind the steering wheel and carries signals to the driver's airbag and horn. Constant steering rotation wears it out over years, and replacement typically runs from around £80 for parts alone up to £250 to £300 fitted, depending on vehicle.
- Wiring or connector damage under the seats. Seat sliding and general wear can chafe cables feeding seatbelt pretensioners or occupancy sensors. Repairs here range from a straightforward £50 to £100 connector fix to several hundred pounds if the loom itself needs replacing.
- Occupancy or weight sensor faults. These sensors, built into the seat cushion, tell the ECU whether to deploy a passenger airbag. Faulty units usually need replacing rather than repairing, and costs vary by make.
- Crash data stored in the airbag ECU. After a collision, even a minor one, the module can log crash data and refuse to clear the light even once everything mechanical is sound. Here the choice is between a full ECU replacement, which can run into hundreds of pounds once dealer programming is included, or a crash-data reset of the original unit.
Treat every figure above as a guide rather than a quote. Reprogramming requirements and part availability shift the final number considerably.
Can you drive or pass an MOT with the airbag light on?
No. The DVSA's MOT inspection manual classifies an illuminated SRS warning light indicating a system malfunction as a Major defect, which means an automatic MOT failure. There's no discretion here for testers.
Beyond the test certificate, there's a genuine safety and liability question. If your airbags are known to be faulty and you're involved in a collision, that knowledge could complicate an insurance claim or any liability dispute afterwards. The sensible approach is to book a diagnostic as soon as the light appears and avoid unnecessary long journeys until you know exactly what's wrong.
How do you choose a garage for an airbag diagnostic?
Not every quote labelled "diagnostic" buys you the same thing, so a short conversation before booking saves both money and time.
- Ask directly whether the scan covers SRS and airbag modules, or just the engine ECU. Many advertised "diagnostics" are the latter.
- Confirm in writing whether the diagnostic fee comes off the final repair bill if you proceed.
- Check the garage has professional SRS-capable tools, and manufacturer software access if your vehicle needs it.
- Ask whether a crash-data reset is an option for your module, rather than automatic replacement, and request a written report of the codes found.
A garage that hesitates on any of these questions probably isn't set up for proper SRS work.
Prioritising safety over short-term savings
A cheap code-clear that ignores the underlying fault is a false economy, and often a dangerous one, given what an airbag is actually there to do. Where the module is functionally sound and simply carrying old crash data, a specialist postal reset can be a genuinely sensible, lower-cost alternative to a full ECU replacement. Whichever route you take, keep every receipt and written report. You'll want them if your MOT tester or insurer ever asks questions.
— John
Airbag Reset UK: a straightforward postal reset for crash-data faults
Airbagresetuk exists for the specific case a diagnostic often uncovers: a functionally sound airbag module that's simply holding old crash data and refusing to clear. Rather than paying for a full replacement ECU, which can run into hundreds of pounds once dealer programming is added, you post the module in and get it reset.
Turnaround is typically same-day for most modules received in the morning, with fixed pricing rather than negotiated on the phone. Airbag module resets start from £35 to £46, covering cars and vans, with a dedicated motorhome airbag reset service at £65 for larger vehicles that need specialist handling. If posting the module isn't practical, a mobile reset from £75 brings the same service to your location. Airbagresetuk also price-matches genuine like-for-like quotes.
This only works when the module is functional and the fault is crash data rather than physical damage, so a proper diagnostic still matters first. Once you know that's the case, get your part number, a photo of the module, and your fault code printout ready, then head to the pricing page to book.
Sources
FAQ
How much does it cost to fix an airbag light in the UK?
Diagnosis alone typically runs £50 to £100 at an independent garage, with repair costs on top depending on the fault found. Marketplace figures put average airbag repairs around £137, though a straightforward crash-data reset from Airbagresetuk starts from £35.
How much does it cost to diagnose an airbag light?
Independent garages typically charge £50 to £100, main dealers £120 to £200, and mobile mechanics £60 to £90 for an initial professional SRS diagnostic scan. A basic engine-code read is cheaper but won't detect airbag faults at all.
Can I pass my MOT with an airbag light on?
No. An illuminated SRS warning light showing a malfunction is classed as a Major defect under DVSA rules, which is an automatic MOT failure.
Is it illegal to drive with an airbag light on in the UK?
There's no specific offence tied to the warning light itself, but driving with a known safety system fault can affect liability if you're involved in a collision, and the car will fail its MOT regardless. The safer approach is booking a diagnostic promptly rather than continuing to drive on it.
Will the diagnostic fee be deducted if I go ahead with the repair?
Many garages deduct the diagnostic charge from the final repair invoice, but this isn't universal, so it's worth confirming in writing before booking. If the fault turns out to be crash data rather than physical damage, a postal reset from Airbagresetuk is often the cheaper path forward regardless of what the diagnostic itself cost.