HOW DOES AN ECU REMAP WORK?
Vehicle technology has changed dramatically since the 80's with the integration of computer technology. ECU’s (electronic control units) were introduced to improve performance and efficiency. Initially ECU’s controlled basic processes but as technology advanced, the ECU now controls most of the electronic and mechanical systems in a vehicle: Engine speed, intake, exhaust, timing, fuel ratio and gforce are just a few examples of the parameters.
During global vehicle manufacture a map is created to cope with different environments; altitude, humidity & temperature and behavioural criteria. Behavioural criteria includes differing fuel grades & servicing intervals. Manufacturers take into consideration different driving habits. For example, fuel economy is adjusted for popular road speeds 30mph, 56mph and 70mph.
Each vehicle that leaves the production line is unique, slight variations in bhp and timing are dependant on how well parts have been machined and put together. To avoid costly vehicle assessments, the manufacturer creates a 'one size fits all' approach to maps to faciltate this differences.
To create unique selling points, manufacturers make different power versions of the same engine to get better insurance premiums and improve power or fuel effciency. For example, the VW Golf TDI, has three power options for this car: 110 bhp, 130 bhp and 150 bhp.
Therefore, manufacturers are making adjustments & compromises to vehicle maps to cater to a variety of different conditions & tolerances to preserve vehicle reliability.
HOW IS A REMAP ALTERED?
Vehicles have two important points on the map: Idle and part throttle cruising, these are important for manufacturers because it relates to emissions control. All other points are controlled by a predetermined three dimensional map that enables the vehicle to provide reasonable power and efficiency at a compromise.
When a vehicle is remapped the number of points are increased to facilitate further adjustment to the parameters that increase power, efficiency, torque etc. The scope to which the map can be altered is dependant on vehicle specificationbut the most common are fuel pressure, fuel ratio, ignition timing and boost pressure.
Remapping through the OBD port is the most efficient and non-intrusive tuning method. Correctly done it will yield superb results. Speedfactor uses Swiss technology to connect to the OBD port found in the Connecting our remapping equipment to the OBD port on dash enables us to connect directly to the ECU and the map located inside.
Sometimes it is not possible to connect to the OBD port because thter may not be an OBD port, the port is faulty or it is ‘tune protected’. We use CMD Flashtec technology renowned for unlocking 'locked' OBD ports. The software is updated daily and it is rare now that we cannot map through the OBD.
However, there are other methods available to us and we can access the EEPROM chip inside the ECU which contains map. Back Door Module (BDM) connects directly to the circuit board of an ECU. This method requires the ECU to be removed from the vehicle.