Glossary Of Terms

WARNING: This page is about a different car, the 2011 Jaguar XKR, 2011 Jaguar XK, 2010 Jaguar XKR, and 2010 Jaguar XK. However, it is still accessible from the selected car via links, so may be relevant.

This glossary of terms is intended to cover mainly emissions-related (to SAE J 1930) terminology, and other abbreviations that may be used in this information.

The required term may be looked-up in the left-hand column, and subsequent columns give the standard acronym, unit or abbreviation, and definition.

Term(s)	Acronym/Unit/Abbreviation	Definition
Air Conditioning	A/C
Accelerator Pedal Position	APP	Is a multitrack sensor which inputs the drivers demand into the engine control module (ECM)
After Bottom Dead Center	ABDC	Event occurring after bottom dead center
After Top Dead Center	ATDC	Event occurring after top dead center
Anti-lock Brake System	ABS	System which prevents wheel lock-up under braking by sensing lack of rotation of a wheel(s) and diverting fluid pressure away from it (them)
Alternating Current	ac
Amplitude Modulation	AM
Automatic Temperature Control	ATC
Automatic Transmission Fluid	ATF
Ampere	A	SI unit of current
Ampere hour	Ah
Barometric Pressure	BARO	Pressure of surrounding air at any given temperature and altitude
Battery positive voltage	B+	The positive voltage from a battery or any circuit connected directly to it
Before Bottom Dead Center	BBDC	Event occurring before bottom dead center
Before Top Dead Center	BTDC	Event occurring before top dead center
Bottom Dead Center	BDC	Lowest point of piston travel in a reciprocating engine
Battery Junction Box	BJB
Brake Pedal Position	BPP
Brake Horsepower	BHP	Effective horsepower developed by an engine or motor, as measured by a brake applied to its output shaft
British Standard	BS	Standard specification issued by the British Standards Institution
Brake Traction Control System	BTCS
Bus	Topology of a communication network
Coast Clutch Solenoid	CCS
Camshaft Position	CMP	Indicates camshaft position
Carbon dioxide	CO²	Colorless gas with a density of approximately 1.5 times that of air
Carbon monoxide	CO	Poisonous gas produced as the result of incomplete combustion
Chlorofluorocarbon	CFC
Catalytic converter		In-line exhaust system device used to reduce the level of engine exhaust emissions
Celsius	C	SI term for the Centigrade scale, with freezing point at zero and boiling point at 100 degrees
Compact Disc	CD
Cylinder Head Temperature Sensor	CHT Sensor	A sensor for measuring the temperature of the cylinder head
Central Junction Box	CJB
Crankshaft Position	CKP	Indicates crankshaft position
Clutch Pedal Position	CPP	Indicates clutch pedal position
Controller Area Network	CAN	A communication system which allows control modules to be linked together
Constant Velocity	CV
Cubic centimeter	cm³
Central Security Module	CSM	Electronic module to support security system functionality
Data Link Connector	DLC	Connector providing access and/or control of the vehicle information, operating conditions, and diagnostic information
Driver Door Module	DDM	Electronic module to support driver door functionality
Driver Seat Module	DSM	Electronic module to support driver seat functionality
Daytime Running Lamps	DRL
Deutsche Institut fur Normung	DIN	German standards regulation body
Diagnostic Trouble Code	DTC	An alpha/numeric identifier for a fault condition identified by the On-Board Diagnostic (OBD) system
Direct current	dc	Current which flows in one direction only, though it may have appreciable pulsations in its magnitude
Domestic Data Bus	D2B
Digital Versatile Disc	DVD
Electronic Automatic Temperature Control	EATC
Exhaust Gas Recirculation	EGR
Exhaust Gas Recirculation Temperature Sensor	EGRT	Sensing EGR function based on temperature change
Electronic Brake Force Distribution	EBD
Engine Control Module	ECM	Electronic module to support engine functionality
Electronic Crash Sensor	ECS	Sensor to measure severity of impact
Engine Coolant Temperature	ECT
Engine Oil Pressure	EOP
European On-Board Diagnostic	EOBD
Electronic Pressure Control	EPC
Electrically Erasable Programmable Read-Only Memory	EEPROM
Erasable Programmable Read-Only Memory	EPROM
Evaporative Emission	EVAP	System designed to prevent fuel vapor from escaping into the atmosphere. Typically includes a charcoal filled canister to absorb fuel vapor
Flash Electrically Erasable Programmable Read-Only Memory	FEEPROM
Front Electronic Module	FEM
Flash Erasable Programmable Read-Only Memory	FEPROM
Frequency Modulation	FM
Fuel Pump Driver Module	FPDM
Fuel Rail Pressure	FRP
Generic Electronic Module	GEM
Ground	GND	Electrical conductor used as a common return for an electrical circuit or circuits, and with a relative zero potential
Global Positioning System	GPS
Global System for Mobile Communication	GSM
Gross Vehicle Weight	GVW
Heated Oxygen Sensor	HO2S	Electrically heated oxygen sensor which induces fuelling corrections
Hydrofluorocarbon	HFC
High tension	HT
Hydrocarbon	HC
Idle Air Control	IAC	Stepper motor driven device which varies the volume of air by-passing the throttle to maintain the programmed idle speed
Intake Air Temperature	IAT	Temperature of intake air
Inertia Fuel Shut-off	IFS	An inertia system that shuts off the fuel supply when activated by pre-determined force limits brought about by (e.g.) collision
Input Shaft Speed	ISS	Indicates input shaft speed
Key On, Engine Off	KOEO
Key On, Engine Running	KOER
Kilogram (mass)	kg
Kilogram (force)	kgf
Kilogram force per square centimeter	kgf/cm²
Kilometer	km
Kilometer per hour	km/h
Kilopascal	kPa
Kilovolt	kV
Knock Sensor	KS	Sensor which detects the onset of detonation, and signals the ECM to retard the ignition
Liquid Crystal Display	LCD	Optical digital display system, to which applied voltage varies the way the crystals reflect light, thereby modifying the display
Lighting Control Module	LCM
Light Emitting Diode	LED
Low Tension	LT	Primary circuit of the ignition system, linking the battery to the primary winding in the ignition coil
Left-Hand	LH
Left-Hand Drive	LHD
Mass Air Flow	MAF	System which provides information on the mass flow rate of the intake air to the engine
Manifold Absolute Pressure	MAP	Absolute pressure of the intake manifold air
Manifold Absolute Pressure and Temperature	MAPT
Malfunction Indicator Lamp	MIL	A required on-board indicator to alert the driver of an emission related malfunction
Meter (measurement)	m
Metric (screw thread, e.g. M8)	M
Farad	F	Unit of electrical capacitance
Millimeter	mm
Millimeter of mercury	mmHg
Millisecond	ms
Model year	MY
Newton	N	SI unit of force. 1 N = 0.2248 pounds force
Newton Meter	Nm	SI unit of torque. Must not be confused with nm (nanometer)
Negative Temperature Coefficient	NTC
Naturally aspirated	N/A	Fuelling system using intake air at atmospheric pressure; not supercharged or turbocharged
Noise, Vibration and Harshness	NVH
North American Specification	NAS	Vehicles for sale in the USA and Canadian markets
On-Board Diagnostic	OBD	A system that monitors some or all computer input and output control signals. Signal(s) outside the pre-determined limits imply a fault in the system or a related system
Oxides of Nitrogen	Nox
Oxygen Sensor	O2S	A sensor which detects oxygen content in the exhaust gases
On-board Refuelling Vapour Recovery	ORVR
Output State Control	OSC
Output Shaft Speed	OSS
Passenger Air Bag Deactivation	PAD
Pulsed Secondary Air Injection	PAIR
Passive Anti-Theft System	PATS
Positive Crankcase Ventilation	PCV
Parameter Identification	PID	An index number referring to a parameter within a module without knowledge of its storage location
Park/Neutral Position	PNP
Pulse Width Modulation	PWM
Programmable Electronic Control Units System	PECUS	Process whereby a common ECM is programmed on the production line to suit the market requirements of a particular vehicle
Programmable Read-only Memory	PROM	ROM with some provision for setting the stored data after manufacture
Portable Support Electronics	PSE
Power Steering Pressure	PSP
Polytetrafluoroethylene	PTFE
Random Access Memory	RAM	Fast access memory store which is accessible for entry or extraction of data
Read Only Memory	ROM	Fast access memory in which data is fixed and may not be changed
Restraints Control Module	RCM	Electronic module to support functionality of the Supplemental Restraints System
Radio Data System	RDS
Rear Electronic Module	REM
Remote Keyless Entry	RKE
Right-hand	RH
Right-hand drive	RHD
Research Octane Number	RON
Rear Seat Module	RSM	Electronic module to support functionality of rear seats
Supercharger	SC	An intake system which utilizes a supercharger (mechanically driven device that pressurizes intake air, thereby increasing density of charge air and the consequent power output from a given displacement)
Serial Communications Link	SCL
Standard Corporate Protocol	SCP	A high-speed, serial communications system linking all body system control modules. Control messages and data are passed between modules at up to 786 messages per second
Supplemental Restraints System	SRS
Shift Solenoid	SS	Controls shifting in an automatic transmission
Seat Control Module	SCM	Module controlling the seat motor systems (not electric raise/lower-only seats)
Secondary Air Injection	AIR	System used for a period of time each time the engine is started, unless certain temperature criteria are met. Pumps air directly into the exhaust system which generates extra heat and reduces the time taken for the catalytic converters to reach operating temperature
Service Repair Operation (number)	SRO	Number generated by Jaguar Methods & Techniques system which relates to the time allowed to complete a repair operation. Further information on the system can be found in the separate Jaguar Publications (for each model range) entitled 'Repair Operation Times'
Society of Automotive Engineers	SAE
Timing/Coast Clutch Solenoid	T/CCS
Torque Converter Clutch	TCC
Transmission Control Indicator Lamp	TCIL
Throttle Position	TP
Top Dead Center	TDC
Transmission Control Module	TCM	Controls the shifting pattern of the (automatic) transmission
Transmission Control Switch	TCS	Modifies the operation of electronically controlled transmissions
Transmission Fluid Temperature	TFT	Indicates temperature of transmission fluid
Transmission Range	TR	The range in which the transmission is operating
Turbine Shaft Speed	TSS	Indicates rotational speed of transmission output shaft or turbine shaft
Variable Assist Power Steering	VAPS
Variable Camshaft Timing	VCT	A system by which the relationship of the crankshaft and camshaft may be altered during engine running
Vehicle Identification Number	VIN	Number assigned to the vehicle by the manufacturer, primarily for licensing and identification purposes
Vehicle Speed Sensor	VSS	Sensor which provides vehicle speed information
Worldwide Diagnostic System	WDS	Jaguar approved diagnostic system
Wide Open Throttle	WOT	Full throttle position