Automotive Terminology Glossary

Name	Explanation
A/C	Air Conditioning
ABS	Anti-lock Braking System
AC	Alternating Current
AGM	Absorbent Glass Mat
APP	Accelerator Pedal Position
ATC	Automatic Temperature Control
AUTO	Automatic
BCM	Body Control Module
CAN	Controller Area Network
CD	Compact Disc
CDL	Central Door Lock
CHMSL	Center High Mount Stop Lamp
CKP	Cylinder Position
CMP	Camshaft Position
CO	Carbon Monoxide
DC-DC	Direct Current to Direct Current Converter
DDSP	Driver Side Door Switch
DSC	Dynamic Stability Control
DTC	Diagnostic Trouble Code
EBD	Electronic Brakeforce Distribution
EBS	Battery Sensor
ECM	Engine Control Module
ECT	Engine Coolant Temperature
ECU	Electronic Control Unit
EEPROM	Electrically Erasable Programmable Read-Only Memory
EGR	Exhaust Gas Recirculation
ELR	Emergency Locking Retractor
EMS	Engine Management System
EOT	Engine Oil Temperature Sensor
EPB	Electronic Parking Brake
ESCL	Electronic Steering Column Lock
ETC	Electronic Temperature Control
GPS	Global Positioning System
HC	Hydrocarbons
HFM	Hot Film Mass Air Flow
HO2S	Heated Oxygen Sensor
HRW	Heated Rear Window
HS	High Speed
HVAC	Heating, Ventilation, and Air Conditioning
ICE	In-Car Entertainment System
ICS	Inflatable Curtain
IPK	Instrument Panel Cluster
Km/h	Kilometers per Hour
LCD	Liquid Crystal Display
LED	Light Emitting Diode
LIN	Local Interconnect Network
MAF	Mass Air Flow
MLS	Main Light Switch
MS	Medium Speed
NOx	Nitrogen Oxides
NTC	Negative Temperature Coefficient
OAT	Organic Acid Technology
PAS	Power-Assisted Steering
PCB	Printed Circuit Board
PDC	Parking Distance Control
PLCD	Permanent Magnet Linear Non-contact Displacement
PWM	Pulse Width Modulation
RON	Research Octane Number
SAS	Steering Angle Sensor
SBR	Seat Belt Reminder
SCS	Stability Control System
SCU	Shifter Control Unit
SDM	Supplemental Restraint System Control Module
SRS	Supplemental Restraint System
TCM	Transmission Control Module
TCS	Traction Control System
TMAP	Temperature, Manifold Absolute Pressure
TP	Throttle Position
TPMS	Tire Pressure Monitoring System
TPS	Throttle Position Sensor
TWC	Three-way Catalytic Converter
TXV	Thermal Expansion Valve
VIN	Vehicle Identification Number
℃	Degrees Celsius

ABS: (Anti-lock Braking System) Anti-lock Braking System sends a signal from sensors mounted on the wheels indicating that the wheel is about to lock up, and the controller instructs the regulator to lower the oil pressure in that wheel’s brake cylinder, reducing the braking torque. After a certain time, the original oil pressure is restored, continuously cycling (up to 5-10 times per second), keeping the wheel rotating while maintaining maximum braking torque.

ACC: (Adaptive Cruise Control)

APA: (Auto Parking Assist) utilizes onboard sensors (usually ultrasonic radar or cameras) to identify available parking spaces and controls the vehicle for parking.

AQS: (Air Quality Sensor)

ASR: (Acceleration Slip Regulation) prevents wheel slip during vehicle start and acceleration, especially on uneven surfaces or during turns, keeping the slip rate within 10%-20%. ASR often controls the drive wheel’s driving force, also known as the Traction Control System (TCS), referred to as TRC or TRAC in Japan.

AVM: (Around View Monitor) captures images through multiple ultra-wide-angle fisheye lenses, processes the images for distortion correction and stitching to form a view around the vehicle, providing a top-down view to eliminate blind spots and assist with parking.

BCM: (Body Control Module) primarily controls the vehicle’s body electrical systems, such as lighting, wipers, locks, power windows, sunroofs, and mirrors. The switch signals from these devices are input to the BCM, which directly or via relays controls the corresponding electrical devices.

BSP: (Board Support Package) is a layer between the motherboard hardware and the operating system’s driver layer, generally regarded as part of the operating system, providing support for the operating system and access functions to hardware device registers, ensuring better operation on hardware. In embedded systems, BSP is crucial for maintaining the correct interface with the upper OS.

CAN Bus: (Controller Area Network) is a vehicle bus standard that allows microcontrollers and devices to communicate with each other. Developed by Bosch, it has become an international standard (ISO 11898) and is widely used in automotive computer control systems and embedded industrial control networks.

COBS Serial Communication Protocol: (Consistent Overhead Byte Stuffing)

DMS: (Driver Monitoring System) is typically for Level 2-3 autonomous driving systems, and is meaningless for Level 4 unless safety personnel testing is still required. It monitors for driver distraction, fatigue, or drowsiness, and even unexpected situations preventing driving, such as using a water bottle to deceive the system or arguing with passengers.

DSM: (Driver Seat Module)

DVR: (Digital Video Recorder), commonly known as a dashcam.

EBD: (Electronic Brakeforce Distribution) enhances braking systems, measuring the speed and force of brake pedal application, and sending a pulsed brake fluid signal through the ABS system to stabilize braking force across all brake systems.

ECU: (Electronic Control Unit) also known as the vehicle computer.

ECM: (Electronic Control Module)

ECS: (Electronic Control Suspension System) adjusts suspension stiffness and damper settings based on road conditions, load, and speed.

EMS: (Engine Management System) controls not only fuel injection and ignition but also idle speed, emissions performance, intake control, boost control, failure protection, backup systems, diagnostics, and data communication.

EPB: (Electronic Parking Brake)

ESP: (Electronic Stability Program) enhances vehicle handling and prevents loss of control during dynamic limits.

GRS: (Gesture Recognition System)

HBB: (Hydraulic Brake Boost) assists when engine vacuum is insufficient, automatically increasing system pressure to ease brake pedal effort.

HDC: (Hill Descent Control)

HUD: (Head Up Display)

HVAC: (Heating, Ventilation, and Air Conditioning)

ICCID: (Integrated Circuit Card Identity) is the unique identification number for SIM cards.

IMEI: (International Mobile Equipment Identity) is the unique number used to identify mobile devices on networks, similar to an ID for mobile phones.

IVI: (In-Vehicle Infotainment)

I2C Bus: (Inter-Integrated Circuit) is a simple, bidirectional, two-wire synchronous serial bus developed by Philips.

LDW: (Lane Departure Warning System)

LHS: (Locking Horn Sound)

LIN Bus: (Local Interconnect Network) is a serial network protocol for communication between vehicle components.

LSD: (Limited Slip Differential) improves traction by allowing a certain speed difference between driven wheels during turns.

MCU: (Microcontroller Unit) integrates CPU, memory, and various interfaces on a single chip for control applications.

MIL: (Malfunction Indicator Lamp)

OBD Interface: (On-Board Diagnostics) monitors engine performance and emissions, alerting when issues arise and storing fault codes for diagnostics.

SPI Communication Protocol: (Serial Peripheral Interface) is a high-speed, full-duplex synchronous communication bus developed by Motorola.

SRS: (Supplemental Restraint System)

TCU: (Transmission Control Unit) is used in automatic transmissions for simplified driving.

TCS: (Traction Control System) optimizes traction in various driving conditions.

TPMS: (Tire Pressure Monitoring System) monitors tire pressure in real-time and alerts for leaks or low pressure.

TSP: (Telematics Service Provider) integrates telecommunications and information science for remote communication services in vehicles.

UART: (Universal Asynchronous Receiver/Transmitter) converts data between serial and parallel communication.

VCU: (Vehicle Control Unit) is the central control unit in electric vehicles, managing various signals and ensuring stable operation.

VIN: (Vehicle Identification Number) is a unique identifier for vehicles, consisting of 17 characters that provide information about the manufacturer and specifications.

Ignition States:

Typically, there are four ignition states:

LOCK: Engine off, steering wheel locks at a certain angle, key can be removed.

ACC: Accessory power (e.g., radio) is on, engine circuit is off.

ON: Engine and all accessory circuits are on; this is the normal driving position.

START: Starts the engine; after starting, the key returns to the “ON” position.