Autologic Fix: Various electrical and communication faults

Feb. 8, 2016
The driver reports the vehicle's headlights were staying on, and/or other symptoms.

Brand: Volvo 

Models: MY 2005-2007; S80, XC90, V70, XC70, S60

Symptoms: The driver reports the vehicle's headlights were staying on, even when removing the key from the ignition. Other symptoms include warning messages in the DIM display, warning lamps lit up in the DIM display, brake lights on permanently and a no-start condition. 

Cause: Corrosion in the central electronic module (CEM)or connectors, due to water penetration through the plenum box past the sealing grommets. This produces a number of different functionality symptoms and DTCs to be set.


  • Remove wiper arms
  • Remove plenum chambers
  • Remove wiper motor
  • Remove plenum box
  • Inspect the CEM and connectors for any water ingress
  • Replace the CEM and/or connectors with extension cables (as necessary)
  • Replace with a new modified plenum box and sealing grommets.

Parts needed:

  • Plenum box RHD
  • Rubber grommet
  • Central electronic module (CEM) (Only if necessary)
  • CEM reload software (Only if necessary)
  • Extension cable (36 pin) (Only if necessary)
  • Extension cable (32 pin) (Only if necessary)

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