Checking the control unit for open circuit

• Remove the relay, 2/67.

  Check relay coil driver for an open circuit as follows: activate the relay driver and check the voltage between points 1 and 2 in the relay socket.

  For additional information regarding an open circuit, see Open-circuit, permanent faults .

  HINT: The voltage between 1 and 2 must be the battery voltage. 

  HINT: If the value deviates from this, check the voltage between 2 and the battery voltage, and between 1 and ground, which must both be the same as the battery voltage. 

  HINT: Check for an open circuit as described in  Open-circuit, permanent faults  . 

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

  Additional information: 

  • To access the relay/fuse box in the boot, see Integrated relay/fusebox cargo compartment/Rear electronic module (REM), replacing .
  Fig 1: Identifying VCT2000 Diagnostic Tool Symbol In VIDA

  Courtesy of VOLVO CARS OF NORTH AMERICA.
  Fig 2: Identifying Relays

  Courtesy of VOLVO CARS OF NORTH AMERICA.

Is there a fault? 

• YES 

  Refer to Verification 

• NO 

  Refer to Checking the control unit for a short circuit