Checking the input signal

Press the horn. Check that the signal from the horn reaches the control module.

Read off the value.

The value must display ON when the horn is pressed. Otherwise the signal should read OFF.

HINT: The value is constantly OFF in the event of an open-circuit or a short-circuit to supply voltage. The horn value is constantly ON (horn activated) in the event of a short-circuit to ground. 

Fig 1: Identifying VCT2000 Diagnostic Tool Symbol In VIDA

Courtesy of VOLVO CARS OF NORTH AMERICA.

Is the function OK? 

• YES 

  Refer to Checking the output signal 

• NO 

  Refer to Checking the cable for the input signal