Checking the control module for open-circuits

Fig 1: Identifying Ignition ON

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• Ignition off
• Remove relay 2/111
• Ignition on.

  Check the driver circuit for the relay coil for an intermittent open-circuit as follows: activate the relay driver. Measure the voltage between terminals #1 and #2 on the relay base.

  HINT: The voltage between terminals #1 and #2 should be battery voltage. 

  HINT: If the value deviates excessively, check the voltage between terminal #2 and the battery and between terminal #1 and ground. Both should equal battery voltage. 

  HINT: Do not forget to check that the power supply to the control module is OK. 

  Other information: 

  • To access the integrated relay / fusebox in the cargo compartment, see Integrated relay/fuse box cargo compartment/rear electronic module, replacing
  • See Checking wiring and terminals. Intermittent faults .
  Fig 2: Identifying VCT2000 Diagnostic Tool Symbol In VIDA

  Courtesy of VOLVO CARS OF NORTH AMERICA.
  Fig 3: Identifying Relays And Terminals

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Was a fault detected? 

• YES 

  OKAY:  Troubleshooting has been completed.

• NO 

  Refer to Checking the control module for short-circuits