Notes on the content and handling of diagnosis information in ISTA
Fundamental definitions for diagnosis information
The following information types are assigned to the diagnosis information:
- Functional wiring diagram (identifier SSP-SSP): Wiring diagrams that are embedded in the function structure.
- Component wiring diagram (identifier SSP-BTS): Wiring diagrams that are embedded in the component structure.
- Installation location (identifier EBO-EBO): Graphics that are embedded in the component structure.
- Connector view (identifier STA-STA): Graphics that are embedded in the component structure.
- Pin assignment (identifier PIB-PIB): Articles that are embedded in the component structure.
- Functional description (identifier FUB-FUB): Articles that are embedded in the function structure.
- Brief component description
(FUB-FUB identifier); Articles that are embedded in the component structure.NOTE: Brief component descriptions will only be available as of series F01.
The following special features apply:
- Pin assignments are created for all control units with diagnostic capability. In older series, pin assignments may also be present for further components.
- There are connector views for connectors with 2 or more plug-in contacts.
There is no connector view for high-voltage connectors!
- There are overarching component wiring diagrams (SSP-BTS) in the following forms: ground overview, fuse overview, merger overview, component overview, connector overview
There are ground overviews of all grounding points or ground connectors that are not fully depicted in a functional wiring diagram. They provide information that shows which components are connected at a grounding point or ground connector in the vehicle.
There are fuse overviews for each fuse. They provide information that shows which components are connected to the fuse and where the voltage supply for the fuse comes from. In contrast to the functional wiring diagrams, the fuse overviews show the entire path from the fuse to the components.
There are connector overviews of all connectors that are not fully pictured on a functional wiring diagram.
Component overviews are created for control units with diagnostic capability that are not fully shown by a functional wiring diagram and the supply wiring diagram. In older series, the component overview may also be present for further components. Component overviews provide an overview of all the lines of the respective component. The lines are shown up to the next component, connector or plug connector. Only the main component is identified with text. All other components have a hotspot (Hyperlink) on the rough signs, which leads to further detailed information.
There are connector overviews for plug connectors with 2 or more plug-in contacts. The lines are shown up to the next component, connector or plug connector. The components are not identified with text. They have a hotspot (Hyperlink) on the rough signs, which leads to further detailed information.
- No mirror-inverted installation location is available for right-hand drive vehicles. Exception: The installation position is not mirror-inverted for right-hand drive vehicles but deviates by a significant degree.
- Brief component descriptions (from F01) do not exist for all the electrical rough signs, such as for fuses or for gas generators in individual ignition circuits.
Secure energy supply
Attention!
As of the service pack 2021 (first series launch I20), certain supply lines, (e.g. brake, steering, high-voltage battery unit, exterior lighting, specific control units) are subject to a secure energy supply. These supply lines include terminal 30 and terminal 31.
A maximum of one repair area is permitted in the supply line!
The secure energy supply has the function of supplying specific components with electrical voltage. Under no circumstances, the voltage of these components may drop below a certain level.
Therefore, these supply lines may be repaired only once during their entire service life and over their overall length (i.e. reconnected via a connector after separation).
A second repair area would make the sum of the contact resistances too high, so that a secure energy supply would no longer be ensured.
For this reason, the affected supply lines are marked accordingly in the wiring diagrams. This is done using the following markers:
- Indicator symbol on the supply line
- Color identification (color coding) of the supply line
- Red/black for positive wire (terminal 30)
- Brown/black for ground cable (terminal 31)
- Yellow/black for signal line (supply by a control unit)
- Signal name begins with an exclamation point
| Index | Explanation |
|---|---|
| 1 | Red/black supply line (terminal 30) |
| 2 | Indicator symbol |
| 3 | Signal name (positive wire) with exclamation point |
| 4 | Signal name (ground cable) with exclamation point |
| 5 | Brown/black supply line (terminal 31) |
| Index | Explanation |
|---|---|
| 1 | Indicator symbol |
| 2 | Yellow/black signal line (terminal 30 of control unit) |
| 3 | Brown/black supply line (terminal 31) |
| 4 | Signal name with exclamation point |
Networking of diagnosis articles
From the functional wiring diagram, there are hotspots (hyperlinks) that lead to additional information. The information types are shown in ISTA using tabs. Select the corresponding tab in the ISTA for this.
Special features of lug:
If a bookmark is present in this tab, it indicates that multiple objects representing a single information type are valid for the selected rough sign.
In addition, the tab is labelled with e.g. (1/3): This means: There are 3 valid articles on this tab.
Select the appropriate tab with the bookmark multiple times to view the objects in sequence.
| Index | Explanation |
|---|---|
| 1 | "Bookmark" in red color |
| Index | Explanation |
|---|---|
| 1 | Activate the hotspot first. |
| 2 | Then select the Documents button. |
Starting from the functional wiring diagrams in the function structure, you can navigate through an icon (eye) at the top left in the wiring diagram to functional wiring diagrams.
These functional wiring diagrams can be found in the function structure as of F01 under the structure node "Functional wiring diagrams".
Special feature for functional wiring diagrams:
The functional wiring diagrams show the functional networking of a system. This is designed to accommodate the rising level of networking in the vehicle via the bus systems. The functional wiring diagrams provide an overview of the technical relationships and are intended to make them understandable. The functional wiring diagrams are not intended to be wiring diagrams for troubleshooting! The functional wiring diagrams do not contain any information on plug connections to components and on lines such as cross-section and color.
Search of information objects with the free text search or via the function structure/component structure
In principle, in ISTA you can search for diagnosis articles outside of the guided troubleshooting, i.e. outside of the test module. The "text search" tab is available for this in the ISTA menu.
This is useful, for example, if there is a communication fault for a control unit.
A new search category, "Search in structures," has been added to the text search.
In this process, the system searches in the following structures:
- Function structure
- Service functions
- Product structure
- Component structure
- Component fault pattern
The search options are shown in the following sequence and as a standard selection below the search term:
- Search in structures (selected by default)
- Search in document titles (selected by default)
- Search in document
- Search for document number
The system searches for complete terms and term fragments. The hits may also contain additional scopes beyond the expected hits because the system also searches for term fragments.
Multiple search terms may also be entered at once. In this case, merely the structure nodes containing all terms are evaluated.
No wild cards need to be set for the text search. The exact character string entered will be searched for.
Recommendation:
Search in the document if the search cannot be narrowed down with sufficient precision. This increases the probability of hits in the hit list.
Diagnosis documents can of course also be searched for via the function structure or the component structure. The component structure is sorted according to the electrical rough signs.
With sufficient knowledge of the function structure and the component structure, an efficient search is also possible through them.
Procedure: Navigate to the corresponding structure node. Press the button "start search". Also here, observe the filter settings for the information types!
If the wiring diagram searched for is not in the hit list, start the search again at a higher level.
Contents and schematic diagram of wiring diagram
The wiring diagrams break down the entire electrical system of the vehicle into individual circuits.
The components are arranged on the wiring diagram so that the current course can be followed from to positive terminal (top) to the negative terminal (bottom).
Notes on line check: Press here!
- The schematic diagram of the components and lines is not true to scale. For example, a line that is greater than 1 m in length is not pictured differently from a line that is only a few centimeters in length.
- Normally the vehicle's full equipment is shown in the wiring diagram. It is not possible to create individual wiring diagrams for each equipment specification.
- Content variants are shown on the wiring diagram with the so-called checkmark boxes. Pay attention to the selected brackets, because with a wrong choice on the wiring diagram, no follow-up information can be illustrated.
- Control units that are connected to the high-voltage system are marked on the wiring diagram with the "high-voltage" icon.
- The signal names are once again linked in the wiring diagram.
When the user clicks on the hotspot in the wiring diagram for the abbreviated signal name, the written-out long form of the signal name is displayed for the duration of the runtime.
The long form then indicates the meaning of the signal.
Signal names are still present in the extended wiring diagram navigation ("Overview" button) and can be selected for navigation.
"Birdview" function:
The "birdview" provides orientation on which section of the wiring diagram is currently being displayed.
The "birdview" function (top right red frame) is suppressed in the wiring diagram after 5 seconds. By shifting the wiring diagram, the "birdview" function is displayed in the wiring diagram again.
| Index | Explanation |
|---|---|
| 1 | "Birdview" |
The functional wiring diagram shows individual subfunctions in coordination with the test module.
For reasons of clarity not all the plug connections and line branches are fully depicted within the individual function diagrams. Fuses, ground connectors and solder connectors are depicted on general wiring diagrams if necessary (found via link).
Some of the internal wiring in components is only schematically pictured. High-voltage components always have a warning symbol.
In the following additional details for the contents of the wiring diagram are explained.
| Index | Explanation |
|---|---|
| 1 | Hotspot circuit diagram legend |
| 2 | Hotspot functional wiring diagram |
| Index | Explanation |
|---|---|
| 1 | Entire component |
| 2 | Part of a component |
| 3 | Plug connector connected to the component |
| 4 | Component with screw clamps |
| 5 | Component housing directly connected to vehicle ground |
| 6 | Plug connector connected to the component connecting line |
| Index | Explanation |
|---|---|
| 1 | 1st possible line color |
| 2 | 2nd possible line color |
| 3 | Arrow as icon for either - or |
| Index | Explanation |
|---|---|
| 1 | This fuse also supplies further components.
NOTE:
On the arrow to the right, no hotspot is provided. An overview of the actual electrical connection of the lines can be seen via the hotspot and the further documentation on the high level fuse for voltage supply.
|
| 2 | There may be other cable connectors on the dotted line. |
| Index | Explanation |
|---|---|
| 1 | Component in the junction box: Junction Box Electronics (JBE) |
| 2 | Component in the junction box: Fuse F51 |
| 3 | Junction box consisting of power distribution box and control unit Junction Box Electronics (JBE) |
| Index | Explanation |
|---|---|
| 1 | Red = voltage supply |
| 2 | Brown = ground |
| 3 | Pin number 4 |
| 4 | SFFA signal |
| 5 | Line diameter 0.35 mm2 |
| 6 | Wire color gray and black (GR/SW) |
| 7 | Plug connector rough sign X256 |
| 8 | Ground rough sign X172 |
| 9 | 2 pins in the same plug connector Broken line indicates connecting points of this plug connector. |
| Index | Explanation |
|---|---|
| 1 | Shielded line. |
| 2 | Shielding The 2 on the designation W9110.2 means that 2 lines are shielded. |
Fuse layout
The "fuse layout" node is now available in the function network for vehicles GOx, G1x and G3x. The graphic for the power distribution fuse layout is displayed under this node. The graphic also contains the values indicating the amperage (A) for which the individual fuse is designed. The graphic also contains icons indicating the functions for which the fuse is responsible.
In addition, the components and fuses in the power distributions are linked. Selecting the link displays further information such as the installation location, for example.
The fuse layout will also be available for additional series in the future.
Connector view details
There are connector views for all connectors with 2 or more pins. Exception: There is no connector view for high-voltage connectors!
The connector view shows the detached connector.
Connector view as from E6x:
The icon at the bottom center shows whether it is a pin housing or a socket housing.
If an adapter is available for the connector, the adapter number is entered at the bottom left.
If no adapter is available, there is always an icon for a suitcase. In this case, a check must be carried out with the "Suitcase for electrical contacts test kit".
| Index | Explanation |
|---|---|
| 1 | Connector view details |
| 2 | Adapter number |
| 3 | Symbol of socket housing or pin housing |
| 4 | Internal drawing number |
Installation location
The graphics for new installation locations were raised to a higher level of quality in 2013. The following measures are carried out:
- Adjustment of graphic height to the display on the drain system
- Improvement of graphic resolution.
- Introduction of a detailed overview where useful (usually at the top of the graphic).
- Marking of the installation location with a yellow dot.
- The components themselves in yellow.
- Connectors on the component in blue.
- High-voltage cables in their actual orange.
- Lines carrying 48 V voltage in purple.
- High-voltage components assigned a warning symbol.
Special feature for installation locations for government vehicles and high-security vehicles:
The following graphic shows a notice for government vehicles and security vehicles. The documentation may be incomplete due to external assignment. Since no data is present in the development departments, a standardized graphic is displayed instead of an installation location.
Pin assignments
Pin assignments are created exclusively for control units. There is no individual "pin assignment" information type for control units that are shown in their entirety with all wires in the functional wiring diagram.
If the pin assignments for an individual component are present, they can be accessed by selecting the hotspot to the right of the "pin assignment" tab.
Pin assignment is structured as a table. The table has one column describing the signal type using an abbreviation.
The abbreviations have the following meaning:
- I = Input signal
- A = Output signal
- E/A = Bus signal
- GND = GND/GND
Line colors in the wiring diagram
The line colors are specified in the wiring diagram. Either as text (example BL/RD) or with a colored box with the real line colors (as from E8x and E9x, except E83 and E85)
The high-voltage cables are always shown as thicker lines in orange.
The 48 V lines are always shown as thicker lines in violet.
Important notice on line colors!
The line colors are for orientation.
During the production of the wiring harness, it is not guaranteed that the development specifications (basis for the wiring diagram) are always implemented.
For this reason, the line colors on the wiring diagram can deviate from the line colors in the vehicle!
Only the pin assignment is mandatory for troubleshooting!
High-voltage cables are marked on the wiring diagram in orange, in the same way as in the vehicle!
The 48 Volt lines are always pictured as significant lines with the color violet!
| Wire colors | |||
|---|---|---|---|
| RS | Pink | WS | White |
| GE | Yellow | RT | red |
| TR | transparent | GN | Green |
| SW | Black | BL | Blue |
| GR | Gray | VI | Violet |
| BR | Brown | OR | Orange |
Green: small fuse (MINI)
Red: medium fuse (ATO)
Black: large fuse (MAXI)
New functions for the wiring diagram with extended wiring diagram navigation
Starting with ISTA 3.45, the wiring diagram contains new functions. The objective of ISTA 3.53 is to offer these functions for the following series as well:
- E7x
- E8x, E9x (except E83, E85)
- R5x
By means of these new functions, the navigation in the wiring diagram is easier and information can be retrieved in a more user-friendly way.
Successive additional improvements have been implemented for the extended wiring diagram navigation.
Pressing the "overview" button opens a display window to the right of the wiring diagram.
In this display window, the different groups of the wiring diagram (if available) are listed:
In the lines group, the descriptive long form for the signal names is now also offered in all languages.
Example: DB_VR Signal front right wheel RPM sensor positive connection
The following is a brief description of the extended wiring diagram navigation.
| Index | Explanation |
|---|---|
| 1 | Screen capture of wiring diagram navigation |
| 2 | components |
| 3 | lines |
| 4 | Plug connector |
| 5 | Fuses |
| 6 | Button "Reset" |
| 7 | "Hide lines" button |
| 8 | Show/hide button |
| 9 | Button "overview" Switch wiring diagram navigation on and off. |
Button "overview"
Pressing the "overview" button opens a display window to the right of the wiring diagram.
In this display window, the following groups of the wiring diagram (if available) are listed:
+ components
+ lines
+ Plug connector
+ Connector
+ Fuses
Pressing the + button opens and closes the individual group.
Using the button "Fold in/out", all groups are opened and closed simultaneously.
Functions with one group being open
Three columns are available.
The first column contains a magnifier. When selecting the magnifier, the view is zoomed onto this component in the wiring diagram.
The "identification characteristic" column contains the rough sign. The "Description" column contains the long forms of the rough sign. These two columns can be sorted in ascending or descending order by making a selection in the header. By default, sorting takes place in ascending order following the rough signs.
When selecting a rough sign or its description, the entry in the list is selected. At the same time, the selected rough sign will be marked in color in the wiring diagram.
Functions for the lines in the wiring diagram
Lines can be marked in the list entry "lines". Multiple selection is possible.
Lines can also be selected directly inside the wiring diagram. Multiple selection is possible as well.
Pressing the "Hide lines" button hides all unmarked lines. Pressing the button again will show the hidden lines again.
Button "Reset"
The "Reset" button resets the display of the wiring diagram to the initial status.