note: This article is a compilation of several e-mails that the Automotive
EMC network has received from subscribers on the topic of OEM EMC
Specifications. It has been edited
into a single article by the newsletter editor but is not the original work of
AutoEMC.net. We would like to
thanks those contributors and hope this piece reflects the issues about OEM
Standards they intended to raise in writing to AutoEMC.net.
The main question raised on
the Automotive EMC network is "Can you supply the EMC Specification from
XYZ Motor Co.". It is
something the Automotive EMC network would be delighted to be able to supply but
unfortunately to date our requests to host OEM standards has fallen on deaf
In the arena of EMC
Specifications, one OEM stands out as being the most open and liberal provider;
Ford. The Ford Motor Company have
provided a dedicated website where their EMC standard, their installation
guidelines and a list of approved test houses can be viewed or downloaded (www.fordemc.com).
Among others OEM's General
Motors (GM), Peugeot-Citroen (PSA), BMW, FIAT and Lotus are relatively easy to
approach and, in the experience of AutoEMC.net subscribers, provide their
specifications freely (FIAT and Lotus may by now be using the GM specification).
The main difficulty with this group is knowing who to contact.
Their websites provide very little in the way of access to their
technical services (other than commercial vehicle services) and it is most
likely a deliberate omission to avoid a mass of customers requesting data they
don't need and in many cases would not understand.
Especially poor for
providing data are MG Rover, Renault, Daimler-Chrysler (DC) and Volkswagen-Audi
Group (VAG), these companies have rejected some subscribers requests if they are
not already a Tier 1 or 2 supplier and in some cases simply ignore any efforts
to discuss the issue. The case of
Renault appears to be a reverse creep of a symptom of many Japanese OEM's (see
below) after their acquisition of Nissan.
In the case of DC, despite
the time that has elapsed since the merger of these companies, it seems to be a
case of split responsibilities and no one site appears to want to be found
guilty of providing information. This
is a particularly sad situation as the previous independent specifications of
Chrysler and Mercedes-Benz were good specifications that were relatively easy to
The most secretive companies
with respect to EMC specifications are the Japanese OEM's.
It appears this is a cultural issue and the provision of this information
is seen as potentially highlighting weaknesses in companies' vehicles.
While in the West an EMC specification is seen as good engineering
practice, in the East it would appear as a competition and the company with the
"easiest to meet" EMC specification may be seen as somehow inferior to
those with more stringent requirements.
Automotive EMC network would be delighted to host any OEM specifications for the
use by professional automotive electrical/electronic design engineers and EMC
test engineers. If the OEM's feel
they can not provide the specifications outright, as Ford have, then at least
let this site provide contact details to enable our subscribers to contact the
appropriate departments within your company.
If you can either provide a specification for hosting on this site, or a
link to the appropriate location, or contact within your own organisation please
send details to email@example.com.
The lack of easy access to some OEM specifications causes a dilemma for test houses, how do they advertise the fact that they can test to an OEM specifications if they can't obtain a copy, or if they already have the specification but they are not allowed to provide details. Conversely how can a customer request testing to a specification if they are not allowed by an OEM to provide the specification with the test documentation.
With international standards it can be expected that the test house will have, or can easily obtain, all the relevant specifications. But with a customer specification it is different and we have heard of a situation where an OEM has not allowed a supplier to provide their EMC specification to a test house, and has then refused to supply the test house directly as they are not a supplier to the OEM! This is a restriction of trade, preventing test houses not approved by the OEM from even performing pre-compliance tests.
The Ford approach should be used as a model of good practice for all OEM's; the specification itself is freely available and then additionally Ford audit and approve a number of specific EMC test houses. This allows a supplier to have the early development and pre-compliance work done wherever they wish, then final compliance testing via an approved test facility.
There are many dilemmas for
design consultancies from restricted access to OEM specifications.
The first is providing adequate training for their staff on the
requirements of the OEM’s and what design practices might be needed to meet
certain parts of their EMC specifications.
The consultancy could use these specifications to estimate cost additions
to a product from OEM-to-OEM (if this is necessary).
At the quotation stage for a project the consultancy would have a better
estimate on where they are likely to have problems and which test houses they
are going to be able to use. This
would benefit the client as well as the consultancy as it should improve the
accuracy of the initial quotation.
Few design consultancies
could be drawn on this issue as they do not want to “rock the boat” with
OEM’s, but many did express problems with obtaining OEM EMC specifications,
even when these specifications were listed as a design requirement in the
initial request-for-quote document. It
appears once the contract is awarded the specifications are easier to obtain,
but by this time it is too late to correct for any anomalies in the quote due to
This dilemma is a relatively
easy one to conceive, if you make ABS systems for example you want to make one
system to meet all specifications, but today that is very difficult and due to
other factors is probably impossible. Even so, when first approaching OEM's it would be useful to
have a test result saying "this is where we are in relation to your EMC
requirements" and then determine what else needs to be done to meet the
requirement, or what costs can be saved because you exceed the requirement.
The situation with
aftermarket products is potentially more problematic and few aftermarket
suppliers are familiar with OEM specifications. The minimum legal EMC requirement is relatively easy to meet
compared to the OEM specifications. It
would be beneficial to both the producer who is looking to obtain OEM fit at
some stage, as well as to the consumer, to know that an aftermarket fit product
met the full EMC requirements of specific vehicle makes.
This could be a selling point for these products and a potential safety
Why should an OEM supply this
information freely? They need only
provide it to their current supply chain. Making
it freely available opens the documents for scrutiny by all-and-sundry and any
minor mistakes might be picked upon as poor error checking.
The specification is a proprietary document and may be open to
interpretation, hence a supplier might claim to have met the requirements, but
because of the application they have failed to apply stringent enough tests
according to the OEM. By restricting access to the EMC specification the OEM can
ensure that pattern electrical parts are difficult to produce without the
OEM’s approval, hence ensuring that the electrical safety is tightly
OEM’s all run strict
quality systems and one problem of making the specification freely available is
ensuring that anyone wishing to supply to the specification has the correct and
most up-to-date issue. By
restricting the circulation the OEM can ensure that there is tight document
control and circulation of their specification without having to actively
advertise new issues to ensure the marketplace is aware of changes.
Note: Do you agree with this article or is your experience different to
those reported by some of our subscribers?
We would like to hear any war stories or good practice stories with
relation to OEM EMC specifications. We
would also like to hear from OEM’s and report any progress on obtaining their
EMC specifications, or arguments as to why they should not provide them.
Send comments to firstname.lastname@example.org.
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