Testing vehicles for 

compliance

The manufacturer must demonstrate the correct

function of the system to the appropriate authority.

For EOBD compliance this requires three com-

plete emission cycle runs (NEDC). This is known

as a demonstration test.

A faulty component is installed or simulated

which causes a violation of the emission limits;

two preconditioning cycles are run and then one

complete cycle to show that the error has been

recorded and highlighted via illumination of the

MIL. These phases are defined in EOBD legisla-

tion as:

● simulation of malfunction of a component of

the engine management or emission control

system;

● preconditioning of the vehicle with a simu-

lated malfunction;

● driving the vehicle with a simulated malfunc-

tion over the type 1 test cycle (NEDC) and

measuring the emissions of the vehicle;

● determining whether the OBD system reacts

to the simulated malfunction and indicates

malfunction in an appropriate manner to the

vehicle driver.

Typical failure modes induced to be detected are:

● Petrol/Gasoline Engines

– Replacement of the catalyst with a deteri-

orated or defective catalyst or electronic

simulation of such a failure