Speak the language
of the ECU.
All the technical terms of the ECU and chiptuning world explained clearly. From DPF to DAMOS, from Stage 1 to WinOLS — the complete dictionary for professionals and enthusiasts.
A2L
Symbolic description file (ASAP2 Language) that accompanies a DAMOS file. It contains the structure of the ECU maps with names, axes, conversion factors and units of measure, making the binary data of the control unit readable.
AdBlue
Selective catalytic reduction (SCR) system found on Euro 5/6 diesel engines. It injects urea into the exhaust system to reduce NOx emissions. It can be disabled via ECU software (emulation).
Anti-Lag
System that keeps the turbocharger under pressure even with the throttle closed, introducing delayed combustion in the exhaust. It eliminates turbo lag when exiting a corner or during gear changes. Born in the rally world, it is now also adopted on sporty road builds.
Banco dinamometrico
Professional tool to measure the real power and torque of a vehicle on the ground. Essential for calibrating Stage 2 and Stage 3 remaps. The values measured on the dyno (hp and Nm) are the real ones at the wheels, lower than those declared by the manufacturer at the crankshaft.
BDM
Background Debug Mode — method for directly reading/writing the ECU memory through physical contacts on the board. Used when the OBD port is not available or the control unit is protected.
Boost pressure
Turbocharger pressure, expressed in BAR or PSI. It is one of the main parameters modified during remapping to increase engine power.
CAN bus
Controller Area Network — serial communication network that connects all the vehicle control units to each other (ECU, TCU, ABS, airbag, etc.). It allows real-time data exchange without point-to-point wiring. It is the standard communication protocol on all modern vehicles.
Checksum
Control value calculated mathematically on the ECU file. It must be recalculated correctly after every modification, otherwise the control unit rejects the file or goes into protection mode.
Common Rail
High-pressure diesel injection system where all the injectors share a common rail. It allows multiple injections per cycle and pressures up to 2500 BAR in the most recent versions.
CPC
Acronym with two meanings in the automotive world. (1) Common Powertrain Control: device for the electronic management of fuel mixing and combustion, aimed at limiting emissions. (2) Central Powertrain Computer (Mercedes-Benz): coordinating control unit of the powertrain on models from 2018 onwards, managing torque, accelerator pedal, active exhaust valves and speed limiter.
CRC
Cyclic Redundancy Check — an error-detection algorithm used to verify data integrity during transmission in the digital networks of vehicles, such as in the CAN bus (Controller Area Network) or Modbus protocol.
DAMOS
Database containing the symbolic description of all the parameters of a specific engine control unit. It turns a binary ECU file into understandable and editable maps with real names, axes and values.
DPF
Diesel Particulate Filter — particulate filter found on modern diesel engines. It traps the fine particles produced by combustion. Its software removal (DPF off) is one of the most requested ECU modifications.
DTC
Diagnostic Trouble Code — error code generated by the control unit when it detects a fault. With remapping it is possible to disable specific DTCs linked to removed or modified components.
E85
Fuel made up of 85% ethanol and 15% petrol. It has a very high octane number (around 108 RON), which makes it ideal for remapped turbo engines. It requires an ECU software conversion (Flex Fuel) and often hardware modifications to the injectors and fuel pump.
ECU
Engine Control Unit — the engine control module. It is the computer that manages all the engine's operating parameters: injection, ignition, turbo, lambda, emissions and much more.
EDC17
Bosch ECU platform for new-generation diesel engines. It is one of the most widespread control units on European vehicles and one of the most worked on in professional chip tuning.
EGR
Exhaust Gas Recirculation — system that recirculates part of the exhaust gases into the engine to reduce NOx emissions. It can cause clogging problems and loss of performance; software disabling (EGR off) is very common.
EVAP
System for recovering fuel vapours from the tank. It can be disabled via ECU on track or built vehicles, where the standard tank is replaced.
Flat Shift
Function that allows you to change gear without fully releasing the throttle, keeping torque at maximum during the shift. Widely used in racing.
Fuel Map
Fuel injection map in the control unit. It defines the amount of fuel injected as a function of engine speed and load. It is one of the fundamental maps in remapping.
GPF
Gasoline Particle Filter — see OPF. Particulate filter for direct-injection petrol engines, introduced with Euro 6d. Same concept as the diesel DPF, applied to petrol engines.
Hard Cut
Rev limiter that intervenes by abruptly cutting injection or ignition when the maximum speed is reached. As opposed to the Soft Cut, which instead brings in the intervention gradually.
Injection Timing
Injection advance — the exact moment at which fuel is injected into the cylinder relative to the piston's top dead centre. It directly affects power, torque, consumption and emissions.
Injection Quantity
refers to the exact amount of fuel that the injector releases into the combustion chamber or the intake duct during a single injection cycle.
Injection Qauntity Deviation
In VAG diagnostics (Volkswagen/Audi), this measurement shows the difference between the quantity injected in the specific cylinder and the average of the other cylinders, useful for identifying faulty injectors.
KAT OFF / L20
Software disabling of the post-catalyst lambda sensor (downstream L2/O2 sensor). It allows the elimination of error signals related to the catalytic converter when it is removed.
Knock
Abnormal detonation of the fuel in the cylinder before the spark arrives. The control unit detects it through dedicated sensors and retards the ignition advance to protect itself. The knock fix corrects this strategy.
Lambda
Ratio between the actual air-fuel mixture and the ideal stoichiometric one. Lambda = 1 indicates a perfect mixture. Values below 1 indicate a rich mixture (more fuel), above 1 a lean mixture (more air).
Launch Control
Function that keeps the engine at a preset speed during the launch, allowing maximum traction right from the start. Widely used in racing and drag races.
MAF
Mass Air Flow — sensor that measures the mass of air taken in by the engine. It is one of the main sensors in ECU management: a faulty or uncalibrated MAF causes loss of power, smoke and abnormal consumption.
MAP Sensor
Manifold Absolute Pressure — absolute pressure sensor in the intake manifold. It measures the air pressure before it enters the cylinders. Essential in turbo management: it is often scaled in remaps to handle higher boost pressures.
MED17
Bosch ECU platform for direct-injection petrol engines (FSI, TFSI, TSI). It is among the most widespread control units on VAG group vehicles (Volkswagen, Audi, Seat, Skoda).
OBD
On-Board Diagnostics — standardised diagnostic port present on all vehicles since 2001. It allows reading/writing of the control unit without dismantling anything, using dedicated programming tools.
OPF / GPF
Otto Particle Filter / Gasoline Particle Filter — particulate filter for direct-injection petrol engines, introduced with the Euro 6d regulations. It can be disabled via software like the diesel DPF.
Piggyback
Additional control unit placed between the original ECU and the engine sensors, modifying the incoming and outgoing signals to alter the engine's behaviour. An alternative to direct ECU remapping, but less precise and stable. It does not modify the control unit's original software.
Pops & Bang
Function that generates pops and flames from the exhaust on deceleration, retarding the ignition after the throttle is closed. Much appreciated in the sporting world for the sound effect.
Pop Corn
Extreme variant of Pops & Bang with more frequent and intense pops. It requires precise calibration so as not to damage exhaust components.
SCR
Selective Catalytic Reduction. An advanced technology used on diesel engines to drastically reduce nitrogen oxide (NOx) emissions by up to 90-95%. The system injects a liquid additive called AdBlue into the exhaust gases, turning the NOx into harmless nitrogen and water vapour.
Soft Cut
Rev limiter that intervenes gradually before the maximum speed, progressively reducing injection or ignition. As opposed to the Hard Cut, it is gentler and less wearing on the engine. Used on road cars where comfort is a priority.
Stage 1
Basic ECU software remap without hardware modifications. It exploits the safety margin left by the manufacturer to increase power and torque while maintaining engine reliability and durability.
Stage 2
Advanced remap that requires matched hardware modifications: downpipe, intercooler, sport filter. It allows greater gains than Stage 1 thanks to the improved air flow.
Stage 3
Extreme remap with substantial hardware modifications: upgraded turbine, larger injectors, uprated fuel pump. Reserved for racing builds or track use.
Swirl flap
Spiral flaps in the diesel intake manifold that create turbulence to improve combustion at low revs. They are prone to breaking and can be disabled via ECU (Swirl off).
TCU
Transmission Control Unit — control unit of the automatic or DCT gearbox. Like the engine ECU, it can be remapped to improve shift times, clutch management and sporty behaviour.
TVA
Additional throttle valve present on some diesel engines. It can be disabled via ECU to eliminate the risk of breakage and simplify the intake system.
Torque Limiter
Torque limiter imposed via software by the manufacturer, often to protect the gearbox or other transmission components. It is removed or raised during remapping to unlock the engine's real torque.
Turbo Lag
Response delay of the turbocharger between the moment the throttle is pressed and when the turbo actually comes into pressure. It is caused by the inertia of the turbine. Modifications such as Anti-Lag, Launch Control and Stage 1/2 remaps significantly reduce this phenomenon.
VMAX
Electronic maximum speed limiter. It can be removed or modified via ECU. On many European vehicles the factory limit is 250 km/h by agreement between manufacturers.
Wastegate
Turbocharger discharge valve that regulates the boost pressure by diverting part of the exhaust gases. It can be external (aftermarket) or internal (factory). In remapping, wastegate management is optimised to precisely control the boost pressure.
WinOLS
Professional software for editing ECU files. It allows you to view, edit and save engine maps in 3D graphic format. The de facto standard in professional chip tuning.
Quick index
Want to dig deeper into a topic?
Contact us on WhatsApp. Our team is always available for technical support and advice.
Message us on WhatsApp