Prerequisites: DAS (Diagnose Assistance System)
and appropriate
Developer-Kit key. The
instructions are valid up to version 10/2008 of DAS.
WARNING! Be very
careful when using the Developer functions! Many of them can cause irreversible damage to the
components of the vehicle and may cause personal injury! Please be
aware that modification to some specific systems (airbags, braking systems)
may make the vehicle unsafe for on road use and may violate the local highway
laws, rendering the car not roadworthy in the legal aspect.
This is especially true for the SRS modules,
where unintentional usage of developer options may cause deployment of
airbags/tensioners and other aggressive restraint systems.
Most of the development menus were designed to be
used at the factories in the Germany, therefore they are usually not translated into
English (or your local DAS language). Basic understanding of German terminology
is required to use the extended functions; in doubt, please keep a dictionary
(or electronic translator) handy.
DISCLAIMER: The author of this manual takes no responsibility for any
damage caused by use of the
Developer Kit of DAS. This
option is a very powerful tool but must be used responsibly and with extreme caution. If in
doubt, please do not blindly try the menu options – several of them will
cause EEPROM or FLASH memory damage, requiring the module to be disassembled
and reprogrammed using external tools - this is a troublesome and risky
operation. Unintentional actuation of components may cause mechanical
failures or even risk of fire - please remember, that in Developer Mode DAS
will do exactly what you command, all safety checks and interlocks are bypassed!
1.
What is a
Developer kit?
2.What are the
benefits?
3.How to get
started.
4.Basic usage.
5.Examples of
use.
1. What is a Developer Kit ?
Developer kit is an extension to the Diagnose
Assistance System of Mercedes-Benz vehicles. This extension allows in-depth
manipulation of the configuration, data and programs stored inside the
electronic control units of Mercedes vehicles. This extension is normally
used at the factory in order to facilitate development and testing of
on-board electronic systems. The extension is normally shipped with every DAS
system, however it remains locked until a valid
Developer key is entered into the configuration via
the licensing menu of Star Utilities.
2. What is
the benefit of using it?
As a presumed DAS user you have probably learned already that there are
number of functions that would logically belong to the software options, but
they
are missing from the regular DAS installations. These include recoding
(variant coding) the control units without SCNs (Software Calibration
Numbers), de/activation of commercially sensitive options (in-motion video of
tv/dvd), recoding the configuration of airbag units, seat belt reminders,
changing the configuration of instrument clusters, restoring damaged EEPROM
contents for Comand/APS and other ECUs and many more. There is also an additional
benefit: sometimes control units record a DTCs
(error codes) that are filtered out by the production software. Developer kit
allows unfiltered view on the module's error memory, therefore allowing to see all stored trouble codes, including the masked
ones.
The reasons for disabling these functions in the DAS setups seen at the
dealership are very simple: firstly, risk associated with using them is too
high to open these tools to (very often) under trained and rushing
technicians; secondly, there are several legal obligations that put
restrictions on what the dealer can do and what he can not - for instance,
recoding tv-in-motion, airbags and emission-re lated systems
fall into this category. Thirdly, electronically damaged components very
often result in replacement, therefore repairing
(recoding) would have adverse effect on spare parts revenue.
3. How to get started
Firstly, you need the mentioned
Developer key made
according to your LAN ID. Before scrapping your old key, take note of the LAN
ID (there are some cases when it changes ie. when reconfiguring the hardware)
and the current License Key in the DAS. Both information
can be found in the licensing menu of Star Utilities. Then replace your
current key with Developer key, save and restart DAS. After selection of
vehicle class there should be now a new screen (in German, except V-Series
and W221 where it comes in English) informing you about dangers associated
with using Developer Kit. You are good to go now.
4. Basic usage
Looking at the basic screen of vehicle selection
you might notice the first changes - there are new vehicle series available,
including production prototypes or models not yet commercially available. Important
note: if you are working on a production vehicle and there are two choices of
the car in the menu ("normal" and "prototype") never try
to talk to the car using Prototype data, as this will most probably cause
damage to the electronic units. Usually prototypes are removed from the
software a few months after the commercial launch.
After selecting the vehicle series, proceed to
defining the model, steering, transmission, engine and so on. It is best
however to match the vehicle using VIN. This will of course require a recent
version of the software to cover models produced up to date.
Next proceed to the specific control unit you
want to work on. Almost every ECU now has an additional menu option called
something like:
- Development Data or
- Diagnosis to Plant Specifications or
- Diagnosis/Coding according to Factory
Specifications
…or similar.
Content of this menu usually varies from one unit
to another, but generally they are divided into following submenus:
- Control
Unit Version
Allows raw dump of the ECU identification,
including HW and SW release and so on.
- Actuation's
Apart from actuating the components connected to
the outputs of the control unit (lights, motors, actuators, solenoids, relays
pumps and so on) this menu usually contains number of software routines that
are executed using this menu, ie. resetting the ECU,
enabling test mode and so on.
CAREFUL: Airbag
modules have the option of actuating the airbag firing outputs directly from
this menu. PROCEED
WITH EXTREME CAUTION, DO NOT LET ANYONE SIT IN THE VEHICLE WHEN WORKING ON
THE AIRBAG SYSTEM. Relevant menu options: look for
Crashstufe Ansteuern, Zundkreis (ZK, ZK-Stufe) Ansteuern..
This also applies to actuating other components –
keep in mind that some pumps for example are not intended to be permanently
switched on and they will overheat quickly. Some actuators might be in a
invalid mechanical configuration and they will also get damaged when trying
to move them using Developer menus. Please
keep in mind that in the Developer Mode there are no safety interlocks. In
these cases actuations should be performed only with relevant component
disconnected to check for presence of switched supply voltage.
A good example of benefit of using the Developer
Actuation menu is Rear SAM of the W211 and W219 series: retractable headrests
(RHR) can not be actuated using the standard module actuation menu, however,
in the Development section there is an option of actuating each of three
headrest release motors (or vacuum valves in case of Station Wagon).
For instrument clusters there is a broad choice
of extended testing options, which allow checking the displays, lamps, needle
instruments and so on.
Each module has a varying number of menu choices
so please take your time and explore them in the DAS Simulation mode - do not
expect them to work as expected in DasSIM - usually simulation is limited to
simplest cases only, it is enough however, to get acquainted with the menu
content).
Please also note, that in the Developer menu this
section will also contain executable entry points
for various procedures and routines stored in the
control units: these will usually manipulate the data stored in units’
EEPROM, so be careful with these. Among many different options there is
also usually an actuation called Module Reset
(Steuergerat resetten, SG_Reset or similar) that will reboot the electronic
control unit.
Important note: when
carrying out a module adaptation via the standard DAS menus, the program automatically
takes care of ECU reset, when required. This is not the case when using the
Developer mode – after performing a configuration change to the module, do not expect it
to be in effect right away – carry out a SG_Reset
first! In cases where no option for induced unit reset is available, cycling
the ignition switch might force the module to reload its settings and coding.
- Actual values
Very similar to the regular section of DAS menu,
however the choice of values is usually much broader. Some of the presented
values might come out as hexadecimal numbers, so conversion might be
necessary
- Adaptations
This is where the power of Developer Kit really
shows. I assume that you are already familiar with basic variant coding of
Mercedes control units. In the Developer section, you can do the same with
the following extensions:
- SCN-dependent modules can be recoded without
need for a valid Software Calibration Number (scn code)
- Airbag modules may be freely reconfigured to
match car's equipment (addition/removal of rear side-bags for instance)
- Several models of SRS controllers will allow
erasing of the CRASH DATA after deployment of restraint systems
- COMAND and other head units supporting video
playback may be reconfigured to allow playback in motion
- Custom, complex configurations can be built for
the entertainment modules connected via D2B and MOST optical rings
- Engine control modules may be recoded to match
the engine installed in the vehicle (ie. after a mechanical swap)
- Speed limiters may be removed from engine ECU
- Instrument clusters may be recoded to match
different engine, model, version and so on.
- When adding vehicle trim from different version
(ie. Elegance or Avantgarde components installed into a Classic-level vehicle
trim) they may be activated so ie. Additional lamps or other equipment is
functioning properly.
- Front fog lights can be activated to function
as a cornering aid in vehicles W203, W171, W211 and newer. This coding is
available in the module Front SAM (SAM-V). Please note that in the early W211
models the right SAM (Passenger SAM) also needs to be recoded. I have found a
number of units that were having the cornering light in the Driver SAM but
the appropriate option was missing from the right SAM. In this situation,
only the left cornering lamp will function – to overcome this, a right SAM
would need to be replaced (rather na inexpensive from the second-hand market)
Please note that for RHD vehicles the SAM functions are reversed (left vs.
right, Passenger vs. Driver).
- Rear brake lights can be actitvated to function
as adaptive lights, ie. They will pulse quickly when emergency braking is
detected. Function supported in the rear SAMs as of approx. 06/2005.
- Hazard lights can be configured to switch on
automatically with emergency braking.
Both above options are available in the module
Rear SAM (SAM-F). Same as above.
- And many, many more.
After performing module adaptation always perform
the module reset (see the note under “Actuations”).
5. Real
examples of using developer
Please note, that availability of the specific
range of the Developer functions is highly dependent
on the installed version of the ECU in question. For
instance, recoding the Engine Control Unit might require upgrading its
flashware to a more modern release first. Keep in mind that not all ECUs are
update-able – some of them might need a newer hardware to update the sw
version.
Uprating the speed limited in a gasoline (ME-series controller) engine
control unit
Log on to DAS, connect
to the car, select:
Control Units -> Drive -> ME-SFI 28 ->
Development Data.
Then select the Control Unit Adaptations ->
Explizite Kodierung
This option works quite the same in Diesel engine
models, however i found it more difficult to use (quite frequently modules
are replying with an error message to the attempt of recoding). I was able to
successfully remove the speed limiter on a CDI2 series module from the W210
model and some others as well.
Adding rear airbags to the AB control module
Control
Units -> Body -> Airbag (AB) -> Development Data -> Control
Module Adaptations -> Variant Coding -> Fahrzeugausstatung Kodieren
(the last menu entry can be slightly d ifferent in
various module variants)
Select the drop-down list in the field Airbag
Hinten Rechts and Airbag Hinten Links – set to YES. Back up to the main Airbag
menu, reset the fault codes, cycle ignition, reset fault codes again and
cycle the ignition for 2nd time (this step is very important).
Adding fog lamps to function as a cornering aid
Select
Body, then Driver Side SAM -> Development Data -> Control Unit
Adaptations -> Variant Coding -> Abbiegelicht set to ON (“ja”).
Then go to the Passenger SAM (if present, for
example in 211/219 model series) and similarly, perform the same coding in
the second SAM unit. I have found that quite often cars manufactured prior to
year 2003 have the relevant cornering lights option available in the left
sam, however right sam is missing it. Not a big problem
since these are readily and cheaply available from the second-hand
market.
For all the onboard systems to recognize the new
function you will also need to recode the CGW or EZS and mark the appropriate
factory option in the adaptations.
Hidden error codes
For W211/W219/W230 series with SBC
system, go to the Chassis-> Sensotronic Brake Control (SBC) then enter
Development Data then call up Fault Codes. Most likely, a car that has been
driven for some time will have a code “Event: ABS Bremsung” stored. This
Fault/Event is not normally shown in the general menu of DAS – it is being
filtered. It actually
does not represent
an actual error, just a specific condition (hard braking with ABS
activation). You will find many modules that actually filter out some more or
less useful fault codes.
This menu is also very useful when evaluating
vague fault codes (ie: “Hydraulics fault” in the general version in the
developer menu can be drilled down to something more meaningful like “rear
left release valve stuck in closed state” – this will come in German though).
Adapting the SRS control unit to a new car (different configuration,
different VIN).
First of all erase all present error codes in the
unit if possible. If there are current faults the airbag module might not get
properly reinitialized.
Then proceed to the menu control unit adaptations
-> special functions -> Control Unit is released.
From this point do not turn the ignition off or reset the control module. Proceed to the
menu option “initial startup” where the current configuration will be
reinitialized and new VIN can be written to the control unit.
Please pay attention to the specified
configuration (ie. Does the car have rear side airbags?) otherwise
you will end up with a controller that does not recognize airbags installed
in the vehicle.
After completing the initial startup, reset the
control module (cycle ignition) and erase all fault codes resulting from the
startup process.
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