CAN Bus and Integrated

Systems

Test your knowledge of CAN bus

Try answering the following questions:

1) On a CAN enabled vehicle, which terminals at

     the 16 pin data link connector are used for the 

     powertrain CAN bus?

    A) Terminal 16 (CAN high) and terminal 6 (CAN

         low).

    B) Terminal 14 (CAN high) and terminal 7 (CAN

         low).

    C) Terminal 7 (CAN high) and terminal 16 (CAN 

         low).

    D) Terminal 6 (CAN high) and terminal 14 (CAN

         low).

2) Which of the following combinations of

    electrical systems might you expect to find

    connected to a low speed CAN bus network? 

    A) Central locking, electric seats, electric window

         lifters, driver information display.

    B) Anti theft warning system, automatic

         transmission, electric sun roof, instruments.

    C) Car phone, navigation system, electronic

         stability program, immobilizer system.

    D) Engine control module, anti lock brakes,

         electro hydraulic power steering.

3) What approximate voltage would you expect to

    see on the wires of a dual wire CAN network

    when a recessive bit is being transmitted?

    A) 2.5 volts on each wire.

    B) 5 volts on each wire.

    C) 5 volts on the CAN low wire and 0 volts on the

         CAN high wire.

    D) 3.5 volts on the CAN high wire and 1.5 volts on

         the CAN low wire.

4) What fault would be indicated by a resistance

    test reading of 0.4 Ohms measured between the

    wires of a dual wire CAN bus network with the

    vehicle ignition and all systems switched off.

    A) No fault as this indicates that the CAN bus has

         continuity and is functioning correctly. 

    B) The test reading indicates a short circuit

         between the two wires of the CAN bus network.

    C) This indicates a short to ground on one of the

         CAN wires. Further testing will be necessary to

         establish the faulty wire.

    D) The test reading indicates that the CAN bus is

         still active. Repeat the test reading when the

         CAN bus network has fully shut down.

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