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What is the Engine Control Unit (ECU)?

All modern cars and vans on the road today have an Engine Control Unit (ECU). The ECU can almost be described as the vehicle’s ‘brain’ and contains a processor that takes information from various sensors throughout the engine. It analyses information such as the engine temperature, accelerator pedal angle, oxygen content in the burnt exhaust gases, as well as many more parameters. Using the information from these sensors it can then add the right quantity of fuel at the right time to provide a good mix of fuel economy, performance and emission control when pulling away, overtaking, pottering down the road or zooming down the motorway.

What is ECU Remapping?

When a manufacturer develops a new car, they have to take into consideration all of the conditions it may be subjected to in all the regions of the world in which they intend to sell the model. This means that instead of optimising the ECU’s program, or ‘map’, to deliver the best performance or fuel efficiency, they have to make compromises to the map to take into account differing operating conditions. These could include sub-standard fuels, extreme temperatures and altitude, differing emission laws and even the possibility that vehicle may not be serviced on a regular basis, in accordance with the manufacturers recommended instructions. An ECU remap takes a reading from the ECU’s processing chip of the vehicles standard compromised map and adjusts various parameters within the map. These include fuel pressure, boost pressure (on turbocharged applications), ignition advance and throttle pedal control, amongst others, to release the true performance from the engine. It is a completely safe process, as it is just allowing the engine to perform as it should have, before all the compromises were applied to the original programming.

Every engine has its own unique map.  By adjusting this we can fine-tune the characteristics of the engine; unleashing more power and in many cases reducing fuel consumption too. There are also different ways of mapping a vehicle. All petrol cars sold within Europe since 1st Jan 2001, and diesel cars manufactured from 2003, must have On-Board Diagnostic (OBD) systems to monitor engine emissions. These systems were introduced in line with European Directive 98/69/EC to monitor and reduce emissions from cars. However, OBD systems have been fitted to many vehicles since the early 1990s, and therefore OBD remapping can be carried out on many vehicles that were manufactured prior to the 2001 legislation.

OBD Remapping

Remapping through the OBD port is the most efficient and non-intrusive tuning method.  It allows us to yield some truly amazing results without even opening the bonnet. Connecting our remapping equipment to the OBD port on a vehicle allows us to connect directly to the ECU and the map located inside.

BDM Tuning

Remapping a vehicle through its OBD port is not always possible for a number of reasons: the vehicle may not have an OBD port, the port may be faulty or the port may even be ‘tune protected’. However, there are several other methods available that allow us to access the Electrically Erasable Programmable Read-Only Memory (EEPROM) chip inside the ECU, which contains the all-important map. Back Door Module (BDM) tuning is the process of connecting directly to the circuit board of an ECU, using a specially engineered jig to hold the ECU in place while data pins are connected to the circuitry. This method therefore requires the ECU to be removed from the vehicle and tuned in a clean, safe and static-free environment.

What benefits will I get from remapping my ECU?

ECU remapping will not only improve the engine power and torque figures; it will also sharpen the throttle response and widen the power-band. This will make the power delivery a lot more linear, which in turn will make the vehicle feel a lot livelier to drive and the engine more flexible. Frequently, the vehicles power output is restricted by the manufacturer for no other reason than to ensure that the vehicle fits into a class to suit fleet buyers. As a driving enthusiast, you do not need or want such restrictions placed upon your vehicle’s ECU and its performance, therefore you can benefit from the hidden power and torque locked away within your engine management system.

The other main benefit of remapping will be a reduction in fuel consumption. With the extra torque, especially at the bottom of the rev range, you will see a fuel saving. This is because it will require less throttle input to maintain motorway speeds, you can drive in a higher gear at a slower speed as well as helping significantly when fully laden, towing or on gradients and even in start stop traffic.

What benefits will I get from ECU remapping a turbocharged diesel engine?

Many see the modern crop of turbocharged diesels as the future of road car tuning. These engines offer fantastic potential for reliable low cost tuning without removing any of the appeal of buying and running a turbo diesel powered vehicle, such as economy, reliability and longevity. After your ECU upgrade to your turbocharged diesel engine, you will enjoy:

  • Increased horsepower

  • Increased torque

  • Better throttle response

  • Smoother power delivery

  • Improved fuel economy

  • Safer overtaking

What benefits will I get from ECU remapping a turbocharged petrol engine?

Turbocharged petrol engines have always been regarded as the sports flagship engine for good reason. They boast far higher power & torque figures than a non-turbocharged power-plant with similar displacement, and are usually fitted to the manufacturer’s flagship models. They are also ideal candidates for remapping as the ECU also controls the wastegate (turbo boost pressure control). After your ECU upgrade to your turbocharged petrol engine, you will enjoy:

 

  • Increased torque

  • Better throttle response

  • Smoother power delivery

  • Safer overtaking

  • Increased horsepower

Improvements in fuel consumption on petrol engine vehicles are smaller and nothing like that achieved by diesel vehicles.

What benefits will I get from ECU remapping a non-turbocharged petrol engine?

The naturally aspirated petrol engine, whilst not being the easiest of engines to tune, can still benefit from a 8-15% power increase with added torque by careful reprogramming of various engine parameters within the map. Parameters such as the fuel and ignition curves can be fine-tuned to give better power & torque output. On some engines the camshaft timing can also be tuned within the map, giving additional improvements.

In many cases, ‘after market’ tuning items such as freer flowing exhausts, high flow air filters and re-profiled camshafts can only be fully utilised by the engine once the necessary adjustments have been made within the ECU. Careful recalibration of the correct maps can unlock the potential of your new engine parts. Further power gains may also be available when a higher octane fuel is used, allowing for more ignition timing.

Can I save fuel by remapping?

Yes! When we remap a vehicle, especially when fuel saving is the priority, we focus on improving the low end torque and widening the power-band as far as we can.

This increase in low end torque will mean less throttle pedal input is required to maintain cruising speeds, when fully laden or when on a gradient. It will also mean that the vehicle will be more comfortable in higher gears at slower speeds as well requiring fewer gear changes overall. If you combine these factors with adjusting your driving style to make the most of the extra low-end torque you will see an improvement in fuel consumption. This is most effective on turbo-diesel engines, where the savings could be as much as 20%.

What do you actually modify in my vehicle?

We do not change any hardware in your vehicle, we just modify the operating parameters in the ECU’s program or ‘map’. In many cases the map stored on the ECU’s processor can be accessed via the on-board diagnostics port (OBD) in the vehicle, normally found under the dashboard. In some newer models the ECU will have to be removed from the vehicle and the casing opened, our technicians will then use specialist tools to read the original map straight from the processing chip.

The technician will then upload the original map to our map writing team who will adjust the parameters to maximise the performance, fuel economy or a clever blend of both. Depending on the vehicle and ECU type, the remapping process can take under an hour.  If at any time you wish to return your vehicles ECU to its original default settings, this can be done easily as we always keep a copy of the original software as a backup.

Is ECU remapping legal?

Yes, it is legal to remap an ECU on an engine. Although you should inform your insurance company of any alterations made to your vehicle.

How do I book a remap?

You can call us on freephone number 0333 444 0136. Our Team will be happy to help you. Or you can request a quote via our website here.

Common acronyms related to remapping include:

  • OBD – On Board Diagnostic

  • EOBD – European On Board Diagnostic

  • JOBD – Japanese On Board Diagnostic

  • OBDII – On Board Diagnostic (American standard)

  • MIL – Malfunction Indication Light

  • DTC – Diagnostic Trouble Codes

  • BDM – Background Debug Menu

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