ECU Tuning Glossary
88 essential terms every ECU tuner should know — from lambda to Tricore.
Air/Fuel
Combustion
Ignition
Sensors
MAF (Mass Air Flow)
sensor measuring intake airflowMAP (Manifold Absolute Pressure)
intake manifold pressure sensorIAT (Intake Air Temperature)
sensor measuring intake air temperatureECT (Engine Coolant Temperature)
coolant temp sensorBARO (Barometric Pressure)
atmospheric pressure sensorTPS (Throttle Position Sensor)
throttle pedal/blade position sensor
sensor measuring intake airflowMAP (Manifold Absolute Pressure)
intake manifold pressure sensorIAT (Intake Air Temperature)
sensor measuring intake air temperatureECT (Engine Coolant Temperature)
coolant temp sensorBARO (Barometric Pressure)
atmospheric pressure sensorTPS (Throttle Position Sensor)
throttle pedal/blade position sensor
Engine
Emissions
DPF (Diesel Particulate Filter)
soot filter on diesel exhaustEGR (Exhaust Gas Recirculation)
recirculates exhaust into intakeAdBlue (DEF / SCR)
urea injection for NOx reductionSCR (Selective Catalytic Reduction)
NOx-reducing catalyst with AdBlueAGR (Abgasrückführung)
German term for EGRFAP (Filtre à Particules)
French term for DPF
soot filter on diesel exhaustEGR (Exhaust Gas Recirculation)
recirculates exhaust into intakeAdBlue (DEF / SCR)
urea injection for NOx reductionSCR (Selective Catalytic Reduction)
NOx-reducing catalyst with AdBlueAGR (Abgasrückführung)
German term for EGRFAP (Filtre à Particules)
French term for DPF
Diagnostics
Network
Tuning Files
DAMOS
ECU map definition file (Bosch)A2L
ASAM standard ECU description fileChecksum
integrity validation block in ECU fileCRC (Cyclic Redundancy Check)
common checksum algorithmFMAP (Flash Map)
memory map of ECU flash regions.bin file
raw binary dump of ECU flash.frf (Flash Replacement File)
VAG/Audi flash file format.ori (Original)
naming convention for unmodified dump.mod (Modified)
naming convention for tuned file.kp (KESS file)
KESS3-specific output format.sgo (Siemens dump)
Siemens-specific dump format
ECU map definition file (Bosch)A2L
ASAM standard ECU description fileChecksum
integrity validation block in ECU fileCRC (Cyclic Redundancy Check)
common checksum algorithmFMAP (Flash Map)
memory map of ECU flash regions.bin file
raw binary dump of ECU flash.frf (Flash Replacement File)
VAG/Audi flash file format.ori (Original)
naming convention for unmodified dump.mod (Modified)
naming convention for tuned file.kp (KESS file)
KESS3-specific output format.sgo (Siemens dump)
Siemens-specific dump format
Tuning
Stage 1
software-only tune on stock hardwareStage 2
tune supporting bolt-on hardware modsStage 3
major hardware build with custom tunePops & Bangs
overrun fuel-cut delay for exhaust cracklesLaunch Control
rev-limiter for optimal launchesAnti-Lag (ALS)
keeps turbo spooled off-throttleRev Limiter
maximum engine RPM cutoffSpeed Limiter
top-speed cutoffMAF Scaling
recalibration of MAF sensor curveSpeed-Density
load calculation from MAP+RPM (no MAF)Fuel Trim (STFT/LTFT)
lambda correction valuesEngine Load
% of theoretical maximum airflow
software-only tune on stock hardwareStage 2
tune supporting bolt-on hardware modsStage 3
major hardware build with custom tunePops & Bangs
overrun fuel-cut delay for exhaust cracklesLaunch Control
rev-limiter for optimal launchesAnti-Lag (ALS)
keeps turbo spooled off-throttleRev Limiter
maximum engine RPM cutoffSpeed Limiter
top-speed cutoffMAF Scaling
recalibration of MAF sensor curveSpeed-Density
load calculation from MAP+RPM (no MAF)Fuel Trim (STFT/LTFT)
lambda correction valuesEngine Load
% of theoretical maximum airflow
Forced Induction
Security
Licensing
Hardware
ECU (Engine Control Unit)
main engine computerTCM (Transmission Control Module)
transmission control computerDSG (Direct-Shift Gearbox)
VAG dual-clutch automatic transmissionTricore
Infineon microcontroller family used in Bosch ECUsSPI (Serial Peripheral Interface)
low-level chip-to-chip protocolEEPROM
small persistent memory chipTCU (Transmission Control Unit)
transmission control module
main engine computerTCM (Transmission Control Module)
transmission control computerDSG (Direct-Shift Gearbox)
VAG dual-clutch automatic transmissionTricore
Infineon microcontroller family used in Bosch ECUsSPI (Serial Peripheral Interface)
low-level chip-to-chip protocolEEPROM
small persistent memory chipTCU (Transmission Control Unit)
transmission control module