Trailer Guide Schematics Software

PC interface to SOV

Find here extended description, connector views, and help for diagnostic as well !

Description

  • To connect the PC interface to the Side Of Vehicle socket.
  • To connect the PC interface ISO7638 diagnostic interface (EB+ only)
  • Depending if it is connected on the ECU (ISO11898) or between truck and trailer (ISO11992) the voltage on the communication bus is different, see specific Diagnostic below for the Sub-D 25 plug
  • Cable insulation material : PUR

SUB-D 25 pin plug

DB25 plug.png

Pin Description Color Section (mm2)
25 B+ Red 0.75
22 B- Blue 0.75
16 CAN High Green 0.75
15 CAN Low Yellow 0.75

 

SOV Framatome plug

SOV plug.png

Pin Description Color Section (mm2)
1 B+ Red 0.75
2 CAN High Green 0.75
3 CAN Low Yellow 0.75
4 B- Blue 0.75

Diagnostic

ISO11992 - SUB-D 25 only !

The ISO11992 is a mandatory connection between trucks and trailers. Several messages are sent from both side to the other.

This communication is also used for diagnostic purpose. In the ISO7638 connection, Pin 6 and 7 are used for this communication bus (CAN High and CAN Low).

Test points Condition Required value Measured value Comments
25 / 22 Power ON B+  

If the measured value is below B+, it can indicate a resistance in the wiring

Next steps :

  • check for oxidation marks in the connectors
  • check truck power supply
  • check the continuity of the wires with ohmmeter (R<5Ω for correct operation)
16 / 22 Power ON

CAN High is around 2/3 of B+

Usually between 12V and 18V

  

The required value depends of the load on the CAN bus (amount of message, internal resistance of ECU)

Next step :

  • check for oxidation marks in the connectors
  • check the continuity of the wires with ohmmeter (R<5Ω for correct operation)
15 / 22 Power ON

CAN low is around 1/3 of B+

Usually between 6V and 10V

  

The required value depends of the load on the CAN bus (amount of message, internal resistance of ECU)

Next step :

  • check for oxidation marks in the connectors
  • check the continuity of the wires with ohmmeter (R<5Ω for correct operation)

 

Diagnostic

ISO11898 - SUB-D 25 only !

The Haldex Can bus uses 4 wires, 2 are for power supply, 2 for the communication (CAN High and CAN Low)

It can be used for ECU extensions, diagnostic or telematic.

 

Before to start the checking's, be sure you know the CAN bus layout of the vehicle. Depending on the ECUs mounted, you could find splitters and extension cables to link all the network together.

In practice, always start to check the CAN bus from one end to main ECU (EB+ or U-ABS), then check again the different cable or splitters separately.

Test points Condition Required value Measured value Comments
25 / 22 Power ON  B+  

If the measured value is below B+, it can indicate a resistance in the wiring

Next steps :

  • check for oxidation marks in the connectors
  • check the continuity of the wires with ohmmeter (R<5Ω for correct operation)
16 / 22 Power ON

0V < V < 5V

  

The average voltage of CAN High wire is around 2.5V

Next steps :

  • check for oxidation marks in the connectors
  • check the continuity of the wires with ohmmeter (R<5Ω for correct operation)
15 / 22 Power ON  0V < V < 5V  

The average voltage of CAN Low wire is around 2.5V

Next steps :

  • check for oxidation marks in the connectors
  • check the continuity of the wires with ohmmeter (R<5Ω for correct operation)
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