ASAM Solutions Guide
Case Studies
Bosch Engineering GmbH & ETAS GmbH
Jürgen Meyer
ETAS GmbH:
Featured Standard: ASAM MCD-2 D
Efficient Validation
Summary
Challenge: In compliance with legal requirements,
emission-related ECUs must furnish a standardized
OBD scan tool interface for external access to onboard diagnostics. This interface must be carefully
tested before any ECU can be approved for series
production.
Solution: Bosch Engineering GmbH has developed
a new method for verifying the OBD-CAN data of
the ECU scan tool interface in ETAS INCA, applying
the standard ASAM MCD-2 D (ODX). This method
has already been implemented in a customer project.
Bosch Engineering deploys INCA in combination with
its ODX-LINK diagnostic add-on, plus the ETK interface and the ES59x interface module. With the aid
of the ODX-LINK add-on for INCA, the ODB data
output is captured by the scan tool interface and
recorded in a measurement data file. The same
measurement file (ASAM MDF) logs and records the
ECU data based on A2L/Hex (ASAM MCD-2 MC)
synchronously through the ETK development interface.
Key Benefits: Thanks to the synchronous acquisition
of ETK and diagnostic data, within the same INCA
experiment, the ETAS solution provides a way of
direct data comparison. This approach facilitates the
validation of the OBD scan tool interface.
Situation
Bosch Engineering GmbH deploys the ETAS INCA
software tool in tandem with the ETAS ODX-LINK
diagnostic add-on (based on ASAM MCD-2 D) for
the synchronous acquisition of OBD signals from the
CAN bus and of ECU signals from the ETK interface
by means of an ES59x interface module.
Challenges
The on-board diagnostics functions within the engine
ECU checks all emission-relevant components and
subsystems while faults are being identified, localized,
and stored. In compliance with the statutory requirements, an OBD scan tool is used to acquire the
diagnostic data from the engine ECU through the
standardized OBD interface. During this process the
engine ECU sends calculated signals and sensor
data to the scan tool via CAN bus. An incorrectly
functioning scan tool interface or incomplete or faulty
scan tool parameterization may result in a car
maker having to issue a costly recall campaign.
Success solution
Bosch Engineering GmbH uses the ETAS INCA mea­
surement and calibration tool for the parameterization
and functional verification of the scan tool interface.
The installation of the ETAS ODX-LINK diagnostic
add-on, which is compliant to ASAM AE MCD-2 D
V2.0.1, allows the INCA application to perform diagnostic measurements in a standalone environment or
integrated within its standard ECU calibration and
measurement environment. This combination also
means that it is possible to record both data sources
simultaneously. The ODX-LINK add-on provides the
stock functionality of acquiring and recording standardized OBDII PIDs that are compulsory for all vehicle manufacturers. It is also capable of running
manufacturer-specific ECU dia­gnostics providing the
ability to implement a fully customized solution based
on the needs of the manufacturer.
Synchronous acquisition of OBD and ETK
signals through ES59x interface module
To validate the scan tool interface of a given ECU,
the OBD data needs to be compared with internal
ECU data. To this end, INCA records the measurement data obtained from either an ETK (emulator
test probe) or the development CAN bus, or both
sources. All of the sources are time-stamped by the
ES59x interface module on a common timeline. So
far, Bosch Engineering has used INCA plus a separate tool featuring two different hardware interfaces
to validate the scan tool interface. In this case the
validation was performed by means of screenshots
that did not permit the consistent recording of measurement data or documentation.
Online validation of OBD data
A designated experiment environment is configured
by means of INCA’s user interface to facilitate the
online validation of OBD data. It is freely configurable
and can be used for any kind of project. The variables
selection dialog inserts the OBD, ETK, and CAN
signals into a table of measurements. Once the connection to the ES59x interface module has been
made in the vehicle and the visualization mode
started in INCA, the values supplied by the diagnostic CAN bus, e.g., the “engine coolant temperature”
value can be compared online with the raw variable
supplied by the ETK or development CAN bus.
Offline analysis and documentation
Recorders can be implemented in INCA to record the
data manually or by using a trigger condition that is
fully definable by the user. The current measured
values of the variables within the INCA experiment will
be logged in a measurement file. The recorded measurements can be evaluated by means of the Measured
Data Analyzer (MDA) application supplied with INCA.
Since all of the values of the measured parameters
are correlated to a common time axis, this facilitates
their easy identi­fication and one-on-one comparison.
For further analysis, Bosch Engineering uses a tool
that permits the automation of recurring tasks. It
loads the measurement and compares the OBD
signals taken from the CAN bus with the correlated
signals from the ETK-equipped ECU. For this purpose,
an analytical view is created for each available dia­
gnostic message.
Business Benefits
Recording both OBD and ECU information in a
measurement data file opens the door to the automated validation of scan tool data. The ODX-LINK
diagnostic add-on based on the ASAM MCD-2 D
(ODX) standard enables INCA to acquire ODB data
from the scan tool interface in sync with the data
obtained from the ETK emulator test probe or development CAN bus. A separate scan tool with a
proprietary hardware interface is no longer required.
“The entire development process for
electronic control units (ECUs) makes use of
a diversity of software tools. To fully exploit
the potential efficiency improvements offered
by these tools, their seamless interaction
− together with an easy means of exchanging
data between suppliers and OEMs − is an
indispensable prerequisite that can only be
ensured through the deployment of
standardized data formats and interfaces.
It therefore stands to reason that ETAS tools
support the relevant ASAM standards.“
Figure 1: Acquiring OBD
and ETK signals with the
ES59x interface module.
Figure 2: The engine
coolant temperature
obtained from the CAN
bus and the raw variable
from the ETK-equipped
ECU are available for
online comparison.
Figure 3: Verifying engine
speed in reference to a
timeline.