Frequently Asked Questions

Check out our most frequently asked questions below and if we still can’t answer it here chat to us on live chat, email or give us a call.

What is ECU Remapping?

ECU Remapping is a way of fine tuning the vehicle’s ‘brain’ to make it perform more efficiently. All vehicles have an ECU (Engine Control Unit) and the data file stored on the ECU tells the engine how to run. What we do is simply recalibrate the software on the ECU, either by connecting to the vehicle’s OBD (On-Board Diagnostic) port, bench tuning or by adding a plug and play tuning module kit. We can improve a vehicle’s fuel economy by up to 15%, or increase power by up to 40% using these methods. Remapping is sometimes known as chip tuning, which is an old method of tuning.

Will an ECU Remap invalidate my vehicles warranty?

No it shouldn’t. All codes and diagnostics that a main dealer might read when a vehicle is in for a service or diagnostics will remain exactly the same. We say it with confidence because of the rigorous testing regime all our remap files go through. In addition to this, EU Block Exemption Regulations it is illegal for a vehicle manufacturer to void your warranty because work has been carried out by a third party. This also covers vehicle tuning and engine remapping as long as the failure is not as a direct cause of the modification. We can say with confidence that no JFA tuning remap has ever caused a single failure and we are recognised as supplying some of the best tuning files in the world. To back this, we offer our customers 100% peace of mind knowing that our tuning files are fully insured for up to £2 million by Aviva.

NOTE: As of 2013, the VW Group online dealer tools have the ability to see software on any modified vehicle. When a modified vehicle is plugged in online it is flagged on the system, this flag is called TD1 please read the below overview:

TD1is the VW Audi Group warranty ‘Flag’ for a vehicle that has been modified, this is something you should all be well aware of. If you’re not then please note; since the change in main dealer on-line diagnostic tools throughout 2013 performance software can and will be seen when a vehicle is plugged into online at a main dealer. This is the case even if it’s switched to ‘stock’ mode, it is possible although not confirmed that TD1 could be flagged if a vehicle has been flashed with any tool other than the OEM online system. Our recommendation to make the vehicle owner aware that their warranty will be affected if they have software installed on their vehicle; this isn’t anything new as we’ve never claimed software is undetectable.

Once an ECU/Vehicle is tuned some dealer diagnostics tools can detect it’s been modified. You may loose your manufactures warranty by having your ECU/Vehicle tuned. We are not liable for loss of warranty or repair as the owner of the vehicle wishes to have their ECU/Vehicle modified.

Full Terms and Conditions are found here.

What is "Block Exemption Regulations" for modifications & warranty?

It is a common misconception that purchasing aftermarket and tuning products like sports exhausts and engine upgrades invalidate a car’s warranty. However, that just simply isn’t true.

Since the European Commission passed its new ‘Block Exemption Regulations’ in June 2010, it has become illegal for any dealership in the EU to invalidate a warranty as a result of a modification to the car. This legislation was brought about to help provide competition in the marketplace for repair and maintenance in the automotive industry and will remain in place until at least May 2023.

In the United States, there is similar consumer protection through legislation relating to the more general provision of warranties, under the ‘Magnuson-Moss Warranty Act’ of 1975.

This legislation means that you are actually free to modify your car as you wish.

Before this legislation came into effect, dealers were using restrictive warranty conditions to force owners to use official service and official manufacture parts to maintain their cars and to wrongfully deny warranty coverage.
Block Exemption law was therefore introduced to stop this uncompetitive practice. Without this legislation, owners faced the wholly unreasonable situation where they may buy non-manufacturer parts and the dealers could invalidate the warranty/cancel the service plan on the entire car, or (wrongfully) deny warranty coverage on a completely unrelated area to the non-manufacture part.

Therefore, no dealer is permitted to threaten to invalidate OR actually invalidate a warranty on your car if you do not use Official/Authorised aftersales services or if you do not use parts supplied by the dealer or original manufacturer. If a member of staff at your dealership says otherwise, they are breaking the law.

Block Exemption Regulations 1400/2002′ (in short ‘BER’) state that a warranty is not invalidated where:

  • Parts used are of matching quality as the component used for the assembly of a motor vehicle
  • Parts used are of the same specifications and production standards as those used by the Vehicle Assemblers
  • Parts manufacturers/suppliers are able to issue a quality certificate

Once an ECU/Vehicle is tuned some dealer diagnostics tools can detect it’s been modified. You may loose your manufactures warranty by having your ECU/Vehicle tuned. We are not liable for loss of warranty or repair as the owner of the vehicle wishes to have their ECU/Vehicle modified.

Full Terms and Conditions are found here.

How long will it take to remap my vehicle?

A JFA custom written OBD remap will usually take between 1-2 hours, depending on the vehicle. However, some vehicles especially those requiring bench tuning or dyno can take up to a whole day. Get in contact with us for an idea of how long it will take us to tune your vehicle.

Can the remap be reversed?

Absolutely. We offer this service free of charge if the vehicle is brought back to us. We’ll be very surprised if that’s what you want after taking one of our remap products, however in the case of lease cars some customers prefer to put the car back to standard before returning the car. You might want it back to standard if you are visiting a dealer for warranty or service work, again we will do this for free. Should you lose your tuning files due to dealer actions or parts failure we will be happy to re-install the map onto your car free of charge where possible.

Do I need to notify my insurance company?

Whilst the remap is undetectable to dealer equipment, you should notify your insurance company of any modification to your vehicle. Many insurance companies do not penalise you for upgrades of this nature, particularly if you’re tuning for increased economy however a failure to disclose modifications may invalidate your policy. You may wish to enquire with your insurer if the modification will affect your policy prior to choosing one of our services.


Will the lifespan of my engine be reduced?

No. Our remaps are designed specifically to improve the performance of your vehicle whilst remaining within the tolerances of your vehicles’ components.

Sadly, in attempt to achieve ‘big numbers’ some other companies over tune engines, placing excessive stress on the engine, transmission, cooling systems, etc, leading to reduced life span and reliability of the vehicle. We pride ourselves in producing reliable remaps which do not over stress your vehicle but still produce impressive results.

I have existing modifications, will this affect the remap?

Some existing modifications can improve the gains made by remapping a vehicle, and modifications to parts such as air filters and exhausts reduce restrictions of manufacturer parts. We offer a range of remap packages to cater for a whole host of modifications. If you wish, you can order modifications from us to compliment your map and have them fitted when we remap your vehicle.

What if a main dealer wipes the map with a software update?

No problem, simply bring the vehicle back in and we will take a fresh read of your ECU and write you a new map file free of charge. We offer this as part of our lifetime software support.

Why choose ECU remapping over a diesel tuning box?

ECU remapping is far superior to the diesel tuning boxes. When we remap an ECU it optimises various settings and parameters the ECU controls that a tuning box cannot as diesel tuning boxes can only give more fuel pressure. Here at JF Automotive we do sell tuning boxes for certain applications, but these are high end digital chips that have proven results in the dyno cell. Beware of cheap tuning boxes for sale as these can lead to problems or not have any effect on the vehicles performance at all.

Why we don't you offer ECU remapping for £150!

We asked, “Why do some tuners charge as little as £150?” There are a few factors as to why we do not offer remapping for £100-£200!

We supply custom written files for each vehicle that we remap that take in to account condition, milage and customer request of each vehicle. Our services are fully insured with a 30-day money back guarantee and lifetime support for the tuning software supplied. We constantly invest in the most up to date tuning and diagnostic equipment and software and we offer a quality service to all our customers.

Overall our custom supplied tuning software is of the highest standard that we know of, so if you want the best of the best, choose JF Automotive.

What is covered with the "30-day money back guarantee"

In any case where a customer is dissatisfied with any ecu remap software supplied, within thirty days of the supply date, the customer can request their money back. In order for any refund to be processed, the customer must present their vehicle to our workshop and allow our technicians to restore the vehicle to its original state. On successful completion JF Automotive will refund the cost of the remap to the customer.

No refund can be granted unless the vehicle is returned to the original state by JF Automotive. The 30-day money back guarantee only applies to stage 1 remaps and does not apply to other services like pops and bangs, parts or dyno sessions.
If another modification is purchased alongside a tuning file, which relies on a remap to operate, only the cost of the file is covered by this guarantee. We reserve the right to withdraw this 30 day money back guarantee.

Full terms and conditions can be found here

Is DPF removal legal?

DPF removal is illegal for a vehicle that is used for road use and will invalidate your vehicles MOT. All DPF software or removal work is carried out at the owners risk and intention.

What is bench tuning?

This is one method of tuning a vehicle. It involves physically removing the vehicle’s ECU so that we can connect directly to the ECU’s circuit board which enables us to re-calibrate the vehicle’s ECU before putting everything back as we found it. We can complete all of this in-house. Naturally is takes us a bit longer to tune a vehicle this way but don’t worry, we will let you know which method of tuning we will use on your vehicle when you make your initial enquiry.

What does Stage 1,2 or 3 tune mean?

Stage 1 tune is a software re-calibration only.

Stage 2 tune is software re-calibraited to work with light engine modifications e.g Air Filter, exhaust, intercooler.

Stage 3 tune is software re-calibrated on the dyno for heavy engine modifications e.g Cold air intake, exhaust, intercooler, turbo upgrade and more.

Car insurers we recomend

We recommend the following insurers for modified cars

Keith Michaels

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