High-Security Car Keys Portsmouth – EEPROM and Keyless Programming
Not every car key problem can be solved through the OBD port. On prestige vehicles, performance models, and an increasing number of mainstream cars, the manufacturer has restricted standard diagnostic access to prevent unauthorised key programming. Resolving a lost key or all-keys-lost situation on these vehicles requires a different level of technical capability, one that operates at the hardware level rather than through software alone. Portsmouth Car Keys carries out specialist high security key programming and EEPROM work across Hampshire, attending drivers at their location for jobs that most general locksmiths refer elsewhere.
What does high-security or EEPROM key work cost, and how long does it take?
Portsmouth Car Keys programs keys for high-security and prestige vehicles, including EEPROM and module-level work, at your location across Portsmouth & the PO postcode area. Most jobs take 1–3 hours on site because the key data is read directly from the car's module. Every vehicle is different, so we confirm what is possible and a fixed price from your registration first.
Is an auto locksmith better than going to a main dealer?
For most drivers, yes. We come to the car the same day, so there is no recovery truck, no waiting days for a key to be ordered and no separate booking at a service desk. You get a fixed price before work starts. A dealer can still be the right route for a few newer restricted systems, and we will tell you upfront if that applies.
Last updated
| Price | Fixed quote per vehicle |
|---|---|
| Typical time on site | 1–3 hours |
| Response time | Around 1 hour |
| Makes covered | BMW, Mercedes-Benz, Audi, Volkswagen, Land Rover, Porsche and more |
| Warranty | 12 months on parts and labour |
| Hours | Mon–Sun, 8am–10pm |
Prestige or High Security Vehicle Key Problem in Hampshire? We Can Help
If you have a lost key, a failed key, or an all-keys-lost situation on a prestige, high security, or technically complex vehicle anywhere in Hampshire, call Portsmouth Car Keys. We carry specialist EEPROM programming equipment and have hands-on experience with the security architectures used across BMW, Mercedes, Audi, Volkswagen, Porsche, Land Rover, and a range of commercial vehicles including Iveco. We attend your location rather than requiring the vehicle to be delivered anywhere.
What Is EEPROM Programming and Why Is It Needed?
Standard OBD key programming works by sending a software command through the vehicle's diagnostic port to authorise a new key. Manufacturers who want to prevent this simply disable or restrict that command at the OBD level. When that happens, the only way to access the key data is to go directly to the chip that holds it.
How EEPROM Data Controls Modern Vehicle Key Security
EEPROM (Electrically Erasable Programmable Read-Only Memory) chips store the cryptographic key data that links a car key to a vehicle's immobiliser, and accessing this data directly allows key programming to proceed even when OBD-level access is restricted or unavailable.
The EEPROM chip inside a control module holds the security seed, the immobiliser profile, and in some cases the key counter that tracks how many keys have been authorised. Reading this chip directly, either by removing the module and reading it on a bench programmer or by using specialist in-circuit reading tools, gives the locksmith the data needed to generate a new key without the manufacturer's software pathway.
The Difference Between OBD Programming and EEPROM-Level Access
OBD programming sends commands through the vehicle's diagnostic port to authorise a new key within the existing software permissions. EEPROM programming bypasses those permissions by reading the security data directly from the chip inside the relevant control module.
OBD programming is faster and requires no disassembly. It works perfectly well on most standard vehicles. Where manufacturers have restricted or encrypted the OBD key programming pathway, EEPROM access is the alternative. The two approaches produce the same result, a fully working programmed key, but EEPROM work requires additional equipment, greater technical knowledge, and more time.
Which Vehicles Require EEPROM Programming for Key Replacement?
Vehicles that commonly require EEPROM-level programming include later BMW models, certain Mercedes platforms, Porsche, and a growing number of Volkswagen Group vehicles where the manufacturer has restricted standard OBD key access.
The specific requirement varies by model year and platform rather than simply by brand. A 2015 BMW may programme via OBD while a 2019 equivalent requires EEPROM access. This is why knowing the exact model, variant, and year matters when assessing a high security key job. We confirm the approach required before attending.
How High Security Car Key Programming Works
How Keys Are Programmed When Standard OBD Access Is Restricted
When OBD-level key programming is restricted, the relevant control module is accessed directly, the EEPROM chip is read to extract the security data, a new key is generated using that data, and the module is updated to recognise the new key before being returned to the vehicle.
This process may involve removing the module from the vehicle, reading the chip on a dedicated programmer, calculating the required cryptographic data, and writing the new key profile before reinstalling. On some platforms the chip can be read in-circuit without full removal, which reduces the time involved. The approach depends on the specific module and the security architecture of the vehicle.
How CAS, FEM, BDC, EIS and CEM Modules Are Accessed
Key security data on high security vehicles is stored within specific control modules: the CAS or FEM on older BMW models, the BDC on newer BMW platforms, the EIS on Mercedes, and the CEM on Land Rover, each requiring a different access method and programming approach.
BMW's transition from CAS to FEM to BDC across model generations means the approach changes significantly even within the same brand. The CAS module on an E-series BMW is physically removed and read on a bench programmer. The BDC on an F or G-series sits deeper in the vehicle architecture and may require in-circuit reading. Mercedes EIS modules manage both key authorisation and the ESL steering lock, and work on one affects the other. Land Rover's CEM module controls multiple vehicle systems alongside key security, requiring careful handling throughout.
What Happens in an All Keys Lost Situation on a Prestige Vehicle
In an all keys lost situation on a prestige or high security vehicle, the locksmith must read the EEPROM data from the relevant module to reconstruct the immobiliser profile and generate at least one new working key entirely from scratch.
This is the most demanding version of the job. Without any working key to authenticate against, the entire key security profile must be rebuilt from the data held in the module's EEPROM chip. The process is time-consuming and requires specialist equipment, but it avoids the need to replace the control module entirely, which is a significantly more expensive route. We carry out all-keys-lost work on prestige vehicles across Hampshire as part of our standard specialist service.
How Much Does High Security Car Key Programming Cost in Hampshire?
High security car key programming in Hampshire typically costs between £250 and £600 depending on the vehicle make, the specific security system, whether EEPROM access is required, and the complexity of the all-keys-lost scenario if applicable. Standard prestige key jobs with accessible modules sit at the lower end. All-keys-lost situations requiring full EEPROM reconstruction sit at the higher end. We provide a clear quote based on the specific vehicle before attending.
Why EEPROM and Module-Level Programming Costs More Than Standard Keys
EEPROM programming costs more than standard OBD key programming because it requires specialist hardware, greater technical expertise, more time, and in some cases physical module removal and bench reading.
The equipment used for EEPROM work is significantly more expensive than standard automotive diagnostic tools. The process is more involved, the margin for error is smaller, and the technical knowledge required to work correctly with encrypted security data is considerable. The cost reflects the actual complexity of the job rather than an arbitrary premium for prestige vehicles.
Specialist Locksmith vs Main Dealer for Prestige Key Work – Cost Comparison
A specialist mobile auto locksmith typically carries out prestige key programming at lower cost than a main dealer, without the recovery charges and vehicle transport costs that a dealer visit requires.
Main dealers charge for parts, labour, and diagnostic time, and require the vehicle on their premises. For a prestige vehicle with a key fault that prevents driving, that means recovery costs on top of the dealer bill. A mobile specialist attends the vehicle, carries out the work on-site, and eliminates both the recovery cost and the dealer labour premium in most cases.
Specialist Auto Locksmith vs Main Dealer for High Security Key Programming
For prestige and high security vehicles, the difference between a specialist mobile locksmith and a main dealer is worth understanding before making a decision.
| Specialist Auto Locksmith | Main Dealer | |
|---|---|---|
| Attends your location | Yes | No |
| EEPROM capability | Yes | Yes |
| Module-level access | Yes | Yes |
| All keys lost capability | Yes | Yes |
| Same-day attendance | Yes | Rarely |
| Recovery cost | None | Often required |
| Typical cost | £250–£600 | £400–£900+ |
For most prestige vehicle key situations in Hampshire, the specialist mobile locksmith route is faster, requires no vehicle transport, and costs less than the dealer equivalent.
Specialist Key Programming Available Today Across Hampshire
If you have a high security key problem on a prestige or technically complex vehicle in Hampshire, call Portsmouth Car Keys. We carry EEPROM programming equipment and have experience with the specific security architectures used across the vehicles we cover. Same-day attendance is available across the region for most specialist key jobs.
Can All Keys Lost Be Resolved Without Going to a Main Dealer?
Yes, an all keys lost situation on most prestige and high security vehicles can be resolved by a specialist mobile auto locksmith using EEPROM programming tools, without the vehicle needing to go to a main dealer.
This is the question most drivers with a prestige vehicle key problem ask first, usually after being quoted a significant sum by a dealer. For the majority of vehicles we cover, all-keys-lost is a job we can complete at the driver's location. The module holding the key security data is accessed directly, the EEPROM is read, and a new key is generated from that data. There are some vehicles with genuinely restricted architectures where dealer involvement is unavoidable, and we will always be honest if that applies to a specific job.
High Security Vehicles We Carry Out Key Work On
BMW – CAS, FEM and BDC Module Key Programming
Portsmouth Car Keys carries out BMW key programming across CAS, FEM, and BDC platforms, covering lost key replacement, all-keys-lost scenarios, and spare key programming for models across the BMW range.
The CAS module used on E-series BMW models is one of the most commonly encountered in specialist locksmith work and responds well to bench EEPROM reading when OBD access is restricted. FEM-based systems on F-series models require a different approach, and the BDC architecture on more recent G-series platforms involves additional security layers. We confirm the correct method for the specific model and year before attending.
Mercedes – EIS, ESL and ELV Ignition and Key Programming
Portsmouth Car Keys carries out Mercedes key and ignition programming across EIS platforms, including ESL and ELV steering lock work where the ignition and steering systems are linked.
The Mercedes EIS module manages key authorisation alongside the ESL steering lock assembly, which means that faults in either component affect the other. On certain Mercedes models the ELV electronic steering lock is also involved. Work on any of these components needs to account for the relationship between them. We carry the specialist tools to read, programme, and where necessary reset the EIS and ESL systems across the Mercedes range.
Audi and Volkswagen – Immobiliser and Advanced Key Programming
Portsmouth Car Keys provides specialist immobiliser and key programming for Audi and Volkswagen vehicles, including advanced platforms where the Immo Box, cluster, or dedicated security module requires EEPROM-level access.
Later Audi and Volkswagen Group vehicles have progressively restricted standard OBD key programming access. On some platforms the immobiliser data is held within the instrument cluster. On others a dedicated Immo Box or BCM2 module is involved. We carry equipment that handles these platforms and confirm the specific access method required based on the exact model before attending.
Land Rover and Range Rover – CEM and Smart Key Programming
Portsmouth Car Keys carries out Land Rover and Range Rover key programming including CEM module access, smart key and proximity entry replacement, and all-keys-lost work across the Freelander, Discovery, and Range Rover range.
Land Rover's CEM module is one of the more complex control modules encountered in mobile locksmith work, managing a range of vehicle systems alongside key security. Smart key and proximity entry programming on Land Rover and Range Rover models requires KESSY-compatible tools alongside the EEPROM capability needed for module-level access. We carry both and have hands-on experience with these platforms across the Hampshire area.
Porsche, Mazda and Iveco – Specialist Key and Security Programming
Portsmouth Car Keys provides specialist key programming for Porsche, Mazda, and Iveco vehicles, covering advanced immobiliser systems, smart key replacement, and commercial vehicle key programming at the driver's location.
Porsche's key security on the Cayenne, Panamera, and 911 shares architecture with the wider Volkswagen Group but with additional layers applied at the Porsche platform level. Mazda's more recent models use advanced immobiliser configurations that require specialist equipment beyond standard OBD tools. Iveco commercial vehicles, including the Daily range, use dedicated commercial software platforms that differ significantly from passenger vehicle programming, and we carry the tooling to cover these as part of our standard Hampshire service.
Why Choose Portsmouth Car Keys for Prestige and EEPROM Work?
Hands-On Experience With High Security Vehicle Systems
Portsmouth Car Keys has hands-on experience carrying out EEPROM programming and module-level key work across prestige and high security vehicles, built through over 5 years of specialist mobile locksmith practice in Hampshire.
Reading about a security architecture is not the same as working on it repeatedly at the roadside. The familiarity that comes from having carried out CAS module programming, EIS system work, and BDC-based key replacement multiple times is what makes the difference on a job where the margin for error is very small. We don't treat prestige vehicles as edge cases.
Specialist Equipment for Module-Level Key Programming
Portsmouth Car Keys carries dedicated EEPROM reading and writing hardware, in-circuit programming tools, and specialist automotive diagnostic software for high security vehicle platforms, all transported to the driver's location.
The equipment used for EEPROM work is not general-purpose. Bench programmers for specific module families, in-circuit reading tools for platforms that don't support module removal, and the cryptographic software needed to generate correct key data from raw EEPROM content are all part of the specialist toolkit. We carry what the job requires rather than working around equipment limitations.
Attending Your Location – No Dealer Transport Required
Portsmouth Car Keys attends the driver's location anywhere in Hampshire for prestige and high security key work, eliminating the recovery cost and dealership logistics that most high security key problems otherwise involve.
A prestige vehicle that can't be driven because of a key fault is a vehicle that costs money to move before any key work even begins. We eliminate that entirely by coming to the vehicle. Whether it's on a private driveway in Fareham, in a car park near Portsmouth's Gunwharf Quays, or on a residential street in Waterlooville, the specialist key work happens at the vehicle's location.
Mobile High Security Key Programming Across Hampshire
Portsmouth, Gosport and Fareham
Portsmouth Car Keys provides mobile high security key programming across Portsmouth, Gosport, and Fareham, attending prestige and technically complex vehicle key jobs at the driver's location.
From driveways in Southsea to the waterfront areas of Gosport and the residential streets around Fareham, our specialist mobile service covers this central stretch of Hampshire for EEPROM and module-level key work.
Havant, Waterlooville and Cosham
High security car key programming in Havant, Waterlooville, and Cosham is available from Portsmouth Car Keys, with specialist mobile attendance for prestige vehicle key jobs across all three areas.
Drivers in Bedhampton, Cowplain, or the roads around Cosham near the A3 can have specialist EEPROM key work carried out at their vehicle without any need for recovery or dealer transport.
Portchester, Lee-on-Solent and Surrounding Areas
Portsmouth Car Keys covers Portchester, Lee-on-Solent, and the surrounding Hampshire areas for high security key programming, reaching drivers along the M27 corridor and across the Gosport Peninsula.
Whether the vehicle is near the M27 junction at Portchester or on the coastal roads of Lee-on-Solent, our specialist mobile unit covers these locations as part of the standard Hampshire service area.
High Security Car Keys and EEPROM Work – Frequently Asked Questions
EEPROM programming is a method of accessing the cryptographic key security data stored directly on a chip inside a vehicle's control module, allowing a new car key to be programmed even when standard OBD diagnostic access is restricted.
The EEPROM chip inside modules such as the BMW CAS, Mercedes EIS, or Land Rover CEM holds the data that links authorised keys to the vehicle's immobiliser. Reading this chip directly allows a specialist locksmith to reconstruct the key profile and generate a new working key without needing the manufacturer's software-level authorisation pathway. It is a more involved process than standard OBD programming, but it is the correct approach when OBD access is unavailable or restricted.
High Security Key Problem? Call Portsmouth Car Keys for Specialist Help Today
If you have a lost key, an all-keys-lost situation, or a key fault on a prestige or high security vehicle anywhere in Hampshire, Portsmouth Car Keys is ready to help. We carry the specialist EEPROM programming equipment and have the hands-on experience to handle technically complex key jobs at your location, without recovery, without a dealer visit, and without delay.
Call Portsmouth Car Keys today for specialist mobile high security car key programming across Hampshire.
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Portsmouth Car Keys
023 9299 0167Mon–Sun, 8am–10pm
Mobile service – we come to you across Portsmouth & the PO postcode area
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What prestige car owners say
Amazing service! Very responsive to phone call, arrived in less than one hour and job done in 20 minutes. I highly recommend.
Fantastic service! I called for help when I lost my car key and the locksmith arrived quickly, was super professional, and had everything fixed in no time. Very friendly and knowledgeable. Highly recommend for anyone needing reliable and efficient locksmith services!
Thank you for doing my navara lost keys so promptly professional and fast
Very fast response, professional service. Resolved my issue, highly recommended
Awesome service after I lost my only key one evening; offered to come out, took much of the central console apart and sorted the issue in what seems like no time. Excellent skills and comms throughout; absolutely recommended! Top job!!
Excellent service for my BMW 3 series with failed manual lock that he repaired quickly, replacing worn cam. Cannot recommend too highly.
Outstanding patience and top skills lead to unlocking and providing a new key to her Kia Sportage enabling her to return home after a very traumatic previous day’s experience . I cannot praise their skills highly enough. Highly recommend this company.
Did the work at a 3rd of the price of the dealership and I’m sure to a higher quality, the work was quick and professional. Could not recommend more!
Came to Gosport at quite short notice and quickly and efficiently opened the car, cut and coded two key at a very good price. Thank You, I would definitely recommend them.
Polite and speedy, couldn’t have asked for a better Sunday service. He made it look so easy, I have no hesitation in recommending them.
Amazing service! Very responsive to phone call, arrived in less than one hour and job done in 20 minutes. I highly recommend.
Fantastic service! I called for help when I lost my car key and the locksmith arrived quickly, was super professional, and had everything fixed in no time. Very friendly and knowledgeable. Highly recommend for anyone needing reliable and efficient locksmith services!
Thank you for doing my navara lost keys so promptly professional and fast
Very fast response, professional service. Resolved my issue, highly recommended
Awesome service after I lost my only key one evening; offered to come out, took much of the central console apart and sorted the issue in what seems like no time. Excellent skills and comms throughout; absolutely recommended! Top job!!
Excellent service for my BMW 3 series with failed manual lock that he repaired quickly, replacing worn cam. Cannot recommend too highly.
Outstanding patience and top skills lead to unlocking and providing a new key to her Kia Sportage enabling her to return home after a very traumatic previous day’s experience . I cannot praise their skills highly enough. Highly recommend this company.
Did the work at a 3rd of the price of the dealership and I’m sure to a higher quality, the work was quick and professional. Could not recommend more!
Came to Gosport at quite short notice and quickly and efficiently opened the car, cut and coded two key at a very good price. Thank You, I would definitely recommend them.
Polite and speedy, couldn’t have asked for a better Sunday service. He made it look so easy, I have no hesitation in recommending them.
Amazing service! Very responsive to phone call, arrived in less than one hour and job done in 20 minutes. I highly recommend.
Fantastic service! I called for help when I lost my car key and the locksmith arrived quickly, was super professional, and had everything fixed in no time. Very friendly and knowledgeable. Highly recommend for anyone needing reliable and efficient locksmith services!
Thank you for doing my navara lost keys so promptly professional and fast
Very fast response, professional service. Resolved my issue, highly recommended
Awesome service after I lost my only key one evening; offered to come out, took much of the central console apart and sorted the issue in what seems like no time. Excellent skills and comms throughout; absolutely recommended! Top job!!
Excellent service for my BMW 3 series with failed manual lock that he repaired quickly, replacing worn cam. Cannot recommend too highly.
Outstanding patience and top skills lead to unlocking and providing a new key to her Kia Sportage enabling her to return home after a very traumatic previous day’s experience . I cannot praise their skills highly enough. Highly recommend this company.
Did the work at a 3rd of the price of the dealership and I’m sure to a higher quality, the work was quick and professional. Could not recommend more!
Came to Gosport at quite short notice and quickly and efficiently opened the car, cut and coded two key at a very good price. Thank You, I would definitely recommend them.
Polite and speedy, couldn’t have asked for a better Sunday service. He made it look so easy, I have no hesitation in recommending them.
Amazing service! Very responsive to phone call, arrived in less than one hour and job done in 20 minutes. I highly recommend.
Fantastic service! I called for help when I lost my car key and the locksmith arrived quickly, was super professional, and had everything fixed in no time. Very friendly and knowledgeable. Highly recommend for anyone needing reliable and efficient locksmith services!
Thank you for doing my navara lost keys so promptly professional and fast
Very fast response, professional service. Resolved my issue, highly recommended
Awesome service after I lost my only key one evening; offered to come out, took much of the central console apart and sorted the issue in what seems like no time. Excellent skills and comms throughout; absolutely recommended! Top job!!
Excellent service for my BMW 3 series with failed manual lock that he repaired quickly, replacing worn cam. Cannot recommend too highly.
Outstanding patience and top skills lead to unlocking and providing a new key to her Kia Sportage enabling her to return home after a very traumatic previous day’s experience . I cannot praise their skills highly enough. Highly recommend this company.
Did the work at a 3rd of the price of the dealership and I’m sure to a higher quality, the work was quick and professional. Could not recommend more!
Came to Gosport at quite short notice and quickly and efficiently opened the car, cut and coded two key at a very good price. Thank You, I would definitely recommend them.
Polite and speedy, couldn’t have asked for a better Sunday service. He made it look so easy, I have no hesitation in recommending them.