EMC FLEX BLOG A site dedicated to Automotive EMC Testing for Electronic Modules

CISPR 25 Conducted Emissions Current (CEI) Grounding Scheme

An incorrect DUT grounding scheme can easily make the difference between compliance and non-complian

An incorrect DUT grounding scheme can easily make the difference between compliance and non-compliance to CISPR 25 CEI limits. Sometimes we have to evaluate CEI from two modules, one used as DUT and the other one used as DUT's load (e.g. Module #1 is a PWM maker while Module #2 is an LEDs Lamp).


Christian Rosu, 2021-06-09


31. March 2021 07:12 by Administrator in
A/C = Air ConditioningA/F = Air/Fuel RatioA/T = Automatic Transmission or TransaxleABS = Antilock Br

A/C = Air Conditioning
A/F = Air/Fuel Ratio
A/T = Automatic Transmission or Transaxle
ABS = Antilock Braking System
ABSV = Air Bypass Solenoid Valve
AC = Alternating Current
ACTS = Air Charge Temperature Sensor
AFC = Air Flow Control
AFM = Air Flow Meter
AFS = Air Flow Sensor
ALCL = Assembly Line Communications Link
ALDL = Assembly Line Data Link
APS = Absolute Pressure Sensor
APS = Atmospheric Pressure Sensor
ASDM = Airbag System Diagnostic Module
ATDC = After Top Dead Centre
ATF = Automatic Transmission Fluid
ATS = Air Temperature Sensor
AWD = All Wheel Drive

B+ = Battery Positive Voltage
BARO = Barometric Pressure
BAT = Battery
BCM = Body Control Module
BHP = Brake Horse Power
BMAP = Barometric/Manifold Absolute Pressure Sensor
BPS = Back pressure Sensor
BPT = Back Pressure Transducer
BTDC = Before Top Dead Centre
Btu = British Thermal Units

C = Celsius
C3I = Computer Controlled Coil Ignition
CALPAK = Calibration Pack
CAN = Controller Area Network
CANP = Canister Purge Solenoid Valve
CAS = Crank Angle Sensor
CC = Cubic Centimetres
CDI = Capacitor Discharge Ignition
CEAB = Cold Engine Air Bleed
CECU = Central Electronic Control Unit
CER = Cold Enrichment Rod
CESS = Cold Engine Sensor Switch
CFI = Central Fuel Injection
CFI = Continuous Fuel Injection
cfm = Cubic Feet Per Minute
CID = cylinder identification sensor
CID = Cubic Inch Displacement
CIS = Continuous Injection System
CKP = Crankshaft Position Sensor
CMP = Camshaft Position Sensor
CO = Carbon Monoxide

CO2 = Carbon Dioxide

COP = Coil On Plug ignition

CPI = Central Port Injection

CPU = Central Processing Unit

CSSA = Cold Start Spark Advance

CSSH = Cold Start Spark Hold

CTS = Coolant Temperature Sensor

CTVS = Choke Thermal Vacuum Switch

CVR = Control Vacuum Regulator

dB = Decibels

DC = Direct Current

DEFI = Digital Electronic Fuel Injection

DFS = Deceleration Fuel Shutoff

DIS = Distributorless Ignition System

DIS = Direct Ignition System

DLC = Data Link Connector

DOHC = Double OverHead Camshaft

DTC = Diagnostic Trouble Code

DVOM = Digital Volt Ohm Meter

E2PROM = Electrically Erasable Programmable Read Only Memory

EACV = Electronic Air Control Valve

EBCM = Electronic Brake Control

Module EBM = Electronic Body Module

ECA = Electronic Control Assembly

ECM = Engine Control Module

ECT = Engine Coolant Temperature

ECU = Electronic Control Unit

EDIS = Electronic Distributorless Ignition System

EEPROM = Electronically Erasable Programmable Read Only Memory

E2PROM = Electronically Erasable Programmable Read Only Memory

EFC = Electronic Fuel Control

EFCA = Electronic Fuel Control Assembly

EFI = Electronic Fuel Injection

EGO = Exhaust Gas Oxygen Sensor

EGR = Exhaust Gas Recirculation

EGRPS = EGR Valve Position Sensor

EGRT = EGR Temperature

EI = Electronic Ignition

EMI = Electromagnetic Interference

EMR = Electronic Module Retard

EOS = Exhaust Oxygen Sensor

EOBD = European Onboard Diagnostics

EPOS = EGR Valve Position Sensor

EPROM = Erasable Programmable Read Only Memory (chip)

ESC = Electronic Spark Control

EST = Electronic Spark Timing

EVAP = Evaporative Emission System

EVP = EGR Valve Position Sensor

F = Fahrenheit

FBC = Feedback Carburettor System

FBCA = Feedback Carburettor Actuator

FCS = Fuel Control Solenoid

FDC = Fuel Deceleration Valve

FI = Fuel Injection

FLS = Fluid Level Sensor

ft.lb. = Foot Pound

FWD = Front-Wheel Drive

gal = Gallon

GDI = Gasoline Direct Injection

GEN = Generator

GND = Ground

GPM = Grams Per Mile

GVW = Gross Vehicle Weight

H20 = Water HC = Hydrocarbon

HEGO = Heated Exhaust Gas Oxygen Sensor

HEI = High Energy Ignition

Hg = Mercury

HO2S = Heated Oxygen Sensor

hp = Horsepower

HT = High Tension

IAC = Idle Air Control

IAT = Intake Air Temperature

IATS = Intake Air Temperature Sensor

IC = Integrated Circuit

ICM = Ignition Control Module

ICS = Idle Control Solenoid

ID = Inside Diameter

IFI = Indirect Fuel Injection

IGN = Ignition

ISC = Idle Speed Control

ISO = International Standards Organization

ITCS = Ignition Timing Control System

ITS = Idle Tracking Switch

JAS = Jet Air System kHz = Kilohertz

Km = Kilometres

KOEC = "Key On, Engine Cranking"

KOEO = "Key On, Engine Off"

KOER = "Key On, Engine Running"

kPa = Kilopascals

KS = Knock Sensor

KV = Kilovolts

L = Litres lb.

ft. = Pound Feet

LCD = Liquid Crystal Display

LED = Light Emitting Diode

LHD = Left-Hand Drive

LTFT = Long Term Fuel Trim

LWB = Long Wheel-Base

MAF = Mass Air Flow

MAP = Manifold Absolute Pressure

MAT = Manifold Air Temperature

MCS = Mixture Control Solenoid

MCT = Manifold Charge Temperature

MFI = Multi Port Fuel Injection

MIL = Malfunction Indicator Light

mm = Millimetres

MPFI = Multi Point Fuel Injection

MPG = Miles Per Gallon

MPH = Miles Per Hour

MPI = Multi Port Injection

MPV = Multi-Purpose Vehicle
ms = Millisecond

mV = Millivolts
Nm = Newton Metres

NOX = Oxides of Nitrogen
NVRAM = Nonvolatile Random Access Memory

O2 = Oxygen
O2S = Oxygen Sensor
OBD = Onboard Diagnostics
OBD I = Onboard Diagnostics One

OBD II = Onboard Diagnostics Two

OD = Outside Diameter
OE = Original Equipment
OEM = Original Equipment Manufacturer

OHC = OverHead Camshaft
OHV = OverHead Valve

OS = Oxygen Sensor

P/B = Power Bakes
P/N = Part Number

PA = Pressure Air
PAIR = Pulsed Secondary Air Injection

PAS = Power-Assisted Steering
PCM = Powertrain Control Module

PCV = Positive Crankcase Ventilation
PECV = Power Enrichment Control Valve

PFI = Port Fuel Injection
PID = Parameter ID
PIP = Profile ignition pickup

PNP = Park/Neutral Switch

PPM = Parts Per Million
PROM = Program Read Only Memory (chip)

PS = Power Steering
PSI = Pounds Per Square Inch

PSP = Power Steering Pressure

pt. = Pint
PTC = Pending Trouble Code

PWR = Power to Weight Ratio

Qt. = Quart
RAM = Random Access Memory

RFI = Radio Frequency Interference

RHD = Right-Hand Drive
ROM = Read Only Memory

RON = Rated Octane Number

RPM = Revolutions Per Minute

RWD = Rear-Wheel Drive
SC = Supercharged
SEFI = Sequential Electronic Fuel Injection

SES = Service Engine Soon (light)
SFI = Sequential Fuel Injection
SIPS = Side Impact Protection System

SOHC = Single Over Head Camshaft

SRS = Secondary Restraint System
SRS = Supplemental Restraint System (air bag)

SRT = System Readiness Test
SS = Speed Sensor
SSI = Solid State Ignition

STFT = Short Term Fuel Trim
SWB = Short Wheel-Base

TACH = Tachometer
TB = Throttle Body
TBI = Throttle Body Injection

TC = Turbocharged
TCC = Torque Converter Clutch
TCM = Transmission or Transaxle Control Module

TD = Turbo Diesel
TDC = Top Dead Centre
TDI = Turbo Direct Injection (A turbo charged direct injected diesel engine)

TIV = Thermactor Idle Vacuum Valve
TKS = Throttle Kicker Solenoid

TPI = Tuned Port Injection
TPP = Throttle Position Potentiometer

TPS = Throttle Position Sensor
TPT = Throttle Position Transducer

TSP = Throttle Solenoid Positioner

TV = Throttle Valve
TVS = Thermal Vacuum Switch

TWC = Three Way Catalyst
TWC+OC = Three Way + Oxidation Catalytic Converter

V = Volts
VAC = Vacuum
VAC = Volts Alternating Current

VAF = Volume Airflow
VAF = Vane Airflow Sensor
VCC = Viscous Converter Clutch

VCM = Vehicle Control Module

VDC = Volts Direct Current
VIN = Vehicle Identification Number

VR = Voltage Regulator
VS = Vehicle Sensor
VSS = Vehicle Speed Sensor

VVC = Variable Valve Control

VVT = Variable Valve Timin
WOT = Wide Open Throttle

Christian Rosu


Battery Voltage Dropout

In EMC "dropout" means Battery drops to 0V. FMC1278R3 (CI 260) is an example of various combinations

In EMC "dropout" means Battery drops to 0V. FMC1278R3 (CI 260) is an example of various combinations of such battery voltage dropouts. The problem is that no automotive battery can really drop its output to 0V for say 5 seconds as well as for 50 ms without to blowout a fuse.

 Therefore the only way to simulate correctly a “battery drop to 0V” is to disconnect DUT's B+ line from battery. The test equipment offers such capability to momentarily disconnect the battery during “voltage dropout” simulating a “0V” like condition, practically no current through supply lines to DUT.

This involves the use of PFM200N + VDS200Q + AutoWave to generate the CI 260 type of pulses. PFM200N acts like a very fast switcher disconnecting its output from DUT. So far only FCA (CS.00054) figure it out to ask “open condition” during “0V” battery voltage dropouts. 

In EMC we use the wording “voltage dip” to describe a momentary battery voltage drop (e.g. 4.5V) below minimum supply voltage (e.g. 9V). Obviously in this scenario the Battery B+ line is not disconnected from DUT during the “voltage dip to 4.5V” of 100ms.


Christian Rosu Feb 17, 2021

Test Procedure vs Test Method in automotive electronics EMC testing

11. December 2020 13:13 by Administrator in EMC/EMI, OEM Specs, Standards, Test Methods
Differences between Test Procedures and Test Methods in automotive EMC/EMI vocabulary.

Test Procedure:

  • what the activity is (DUT type)
  • who is to perform the activity (EMC Testing Laboratory)
  • when the activity is to take place

This is more of an EMC Test Plan Template document that:

  • defines the DUT classification and category
  • lists required EMC Test Methods defined by the automotive OEM specs or International Standards (ISO, CISPR, SAE, etc.).

Test Method:

  • how  the actual EMC testing is to be carried out (test equipment configuration)
  • defines measurable data format for reporting and acceptable stress level limits 

This more of a Work Instruction outlined by automotive OEM EMC specs and international standards.

Christian Rosu, Dec 11, 2020.