Instead of expensive test bench tests and meticulous search, manipulations and switch-off devices can be detected by software.
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Long-term investigations: Previous procedures to prove
exhaust gas manipulations to manufacturers often took
months.
Photo: panthermedia.net/Corepics
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Up to now, diesel vehicles had to be put to the test stand in order
to test exhaust gas values and identify
irregularities. Computer scientists from Bochum as well as in San Diego now
developed a software that can analyze 926 engine control programs
from Volkswagen and Fiat within two minutes. Of these, 406 contained potential cut-off devices.
The exhaust gas companies are far from over: last week, over 230
police officers and 23 prosecutors searched the offices of
Daimler. They were looking for clues as to whether Daimler had tampered with
the exhaust gas values of its diesel engines or had merely used
the legally permissible margins. The differences between the laboratory and the road values were
strikingly large for different models.
The exhaust gas aftertreatment can be switched off in the European
Union if the engine could be damaged if the outside temperature is
too cold. This is already under ten or seven degrees Celsius. This "thermofilter" is used generously by car
manufacturers. The question at Daimler is now whether too generous.
Last week, the US authorities filed a lawsuit against Fiat
Chrysler. The group is said to have used a software that switches off the
exhaust gas purification, in order to spare the engine - according
to its own data. The US environmental agency complains that the Group has not
disclosed at least eight software programs for the approval of SUVs
of the Jeep Grand Cherokee type and pick-up trucks of the Chrysler
brand Ram of the 2014 to 2016 model years.
Fiat Chrysler threatened severe sanctions. In the US, Volkswagen already paid $ 22.6 billion in penalties and
compensation for customers. As in the case of VW, Fiat Chrysler's supplier Bosch was also
involved in the development of the control software.
Until now, the various vehicle models had to be brought to the test
rigs and tested with real-drive emission meters on the
road. This lasted for months. There was no way to search the software specifically in the devices
for shutdown codes. One and a half years after the acquaintance of exhaust gas fraud by
Volkswagen, however, there is now for the first time a possibility
to digitally check the code of the shutdown device in these "black
boxes".
Scientists at the Bochum Horst-Görtz Institute of the Ruhr
University Bochum as well as the University of California in San
Diego developed a test software in the course of a year to control
the program code of the engine controls.The researchers drew over 926 different versions of the engine
control software from Volkswagen and Fiat Chrysler from the last
eight years by car manufacturers and tuning companies.
The result of their test: 406 codes contained a shutdown
device. With it, the exhaust gas cleaning can be activated on the test
stand and switched off again under normal driving
conditions. "We were able to find the smoking colt," says Kirill Levchenko of
the University of California.This means the active automatism of the test bench detection, which
has also been used in many models such as the Jetta, the Golf, the
Passat but also in the Audi A and Q series.
A new feature, however, is the evidence for a passive automatism
for the Fiat 500 X system. The EU Commission did not initiate
proceedings against the Italian government until mid-May 2017, as it
did not look at Fiat enough. The researchers showed for the first time that a type of time
switch acts as a defect device: after exactly 1600 s or 26 min and
40 s after the engine start, the exhaust gas purification is
switched off - a test run takes about 20 min. "Fiat is particularly crude," says Thorsten Holz from the
Horst-Görtz Institute.
With its "active" shut-off device, Volkswagen went a little more
refined: the test bench identification evaluated, among other
things, acceleration phases and steering angles. Systemintern was placed in a function block for "customer-specific
acoustic condition" - the "customer" refers to the automobile
manufacturer, thus Volkswagen.
The function block should obviously control the motor sound, but
also controlled the conditions during an exhaust test. The software took into account ten different test profiles to push
down the exhaust gas values in test situations. "The Volkswagen shut-off device is probably the most complex in the
history of the automobile," Levchenko notes dryly.
The scientists point out that "we were able to find strong evidence
that both Bosch cut-off devices were created and then activated by
Volkswagen and Fiat for their respective vehicles." Both manufacturers use the EDC17 diesel engine control unit from
Bosch. The researchers combined reverse engineering techniques from binary
firmware and technical documentation from manufacturers that are
traded in the tuning community to identify the shutdown
devices.
Felix Domke from the Chaos Computer Club is also involved in the
research group, which has already demonstrated proof of a switch-off
device in the Opel Zafira. Jürgen Resch, Managing Director of the German Environment Agency,
criticized in the German radio, however, that the German
authorities, despite the proof, did not work with their own
follow-up measures: "One simply takes care that a former head of
government, Roland Koch, as Opel lawyer With the Minister of
Transport appears and there is a way to prevent such a clear
violation from being implemented. "
The shutdown devices can vary, as shown by the two exampled
examples. In the 1990s, General Motors allowed more fuel to be injected into
the engine in the Cadillacs when the air-conditioning system ran,
aware that emission tests were always carried out with the
air-conditioning system switched off. Because General Motors had not informed the Audit Authority about
this, a fine of $ 11 million was due and half a million vehicles had
to be recalled.
The aim of the scientists is to be able to automatically check the
motor control software of any manufacturer.However, an up-to-date software check is becoming increasingly
important when approval authorities and other testing facilities
have to monitor and check the increasingly complex vehicle
systems.
That the publication of the researchers coincides with the raid of
the Stuttgart public prosecutor's office at Mercedes, however, is
pure coincidence. The allegations against Daimler differ from those against
Volkswagen.This is about a deficient after-treatment of the particle
emissions. However, the consequences could be similarly serious for
Daimler.
Link:
VDI News
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