Fault tracing a vehicle using wiring diagrams

This procedure describes how to fault trace a VDS protocol-based vehicle, using the ranked list and the wiring diagram. The procedure covers how you can use the wiring diagram to locate a faulty wire.

Note

This procedure is only applicable for VDS protocol-based vehicles.

This procedure is based on a case where a customer has a problem with his vehicle. A function in the vehicle does not work properly. The vehicle is already connected to the VIDA workstation and DTCs have been read out. No CSC exists from earlier preplanning.

Add CSC to work list

Expand the Work List menu item in the left-hand menu panel and select Customer Symptom Codes.

ð	The Customer Symptom Codes page with a list of CSC is opened.

Type a search string in the search field for the CSC you need to add and press [Enter] on your keyboard.

ð	The CSC matching the search string you entered are shown in the right-hand panel.

Select CSC by ticking using the checkboxes and click the Add to List button.

ð	A pop-up is shown where you can enter a name and create a new work list.

Enter a list name and click the Create button.

ð	The work list is created and the CSC is added to the new work list.

Check the ranked list

To start fault tracing the vehicle, click Fault Tracing in the left-hand menu panel.

ð	The Fault Tracing page is opened and the CSC you just added to the new work list is preselected. The pre selection generates a ranked list of the most probable cause of the problem. It is always the component at the top of the list that is most likely to be the source of the problem.

The and the icons in the Fault Cause column in the ranked list indicate if there are DTCs or fault cause set for a component. The fault cause gives you information of why there is a DTC set. View the fault cause of the component by moving the mouse pointer over the icons. If you want to view DTCs and DTC information you can click the DTCs tab.

Use the wiring diagram

In this case, the fault cause information for the component in top of the ranked list gives you the information that a circuit is open. The most probable reason for this is that there is something wrong along the signal. To fault trace the open circuit, select the component in the top of the list and open the Wiring Diagrams tab.

ð	The wiring diagram for the selected function is shown. The component in the top of the ranked list is selected and therefore marked in the wiring diagram. Hoover the cursor over the wire to see the signal id.

To view the signal information, right click the wire and select Signal information.

ð	A pop-up is shown.

Find out which components the signal goes between and how to measure the signal and then close the pop-up.
Right click the wire again and select Cable harness image.

ð	A pop-up is shown.

The endpoints for the wire is marked. You can click them to see images for the endpoints. Close the pop-up.
Inspect the wire and connector visually in the vehicle. Measure it according to measurement information in the signal information. Replace the wire or connector if needed. If no replacement is needed, continue by fault tracing the next component in the ranked list.