Test: Sound, AF

On-board monitor system with video module

In order to test the AF lines, work through the corresponding test modules in the diagnostic program for the video module.

System without video module

1st check: Is the sound radio/cassette mode OK?

Sound in radio/cassette mode not OK: Continue troubleshooting in the radio

Sound in radio/cassette mode OK:

2nd check:

• Disconnect plug connection X18805 at navigation computer
  
• Connect V-adapter lead 61 4 470 with 26-pin test box to plug connection X1313
  
• Select oscilloscope in measuring systems.
  
• Test lead MFK1 to pin 9 (+) and pin 18 (-)
  
• Setting:
  Alternating voltage, frequency: 200 Hz, measuring range: +/- 5 V
  
• Select <Information>< volume matching> in navigation system
  
• Activate voice output/test tone under volume matching with rotary knob/push button
  
• Check:
  Is the signal visible on the oscilloscope for the duration of the test tone/voice output?
  
• Signal visible:
  Check lines between navigation computer and radio and repair if necessary. If OK: Continue troubleshooting in the radio
  
• Signal not visible:
  Replace navigation computer.