2002 Volvo S80 BaseFACTORY OEM SERVICE PROCEDURE

Electrical Heater With Timer Function

WARNING: This page does not describe the selected car, but rather 9 other vehicles, including the 2009 Volvo S60, 2008 Volvo S60, 2007 Volvo S60, 2006 Volvo S60, and 2005 Volvo S60. However, it is still accessible from the selected car via links, so may be relevant.
Fig 1: Electrical Heater With Timer Function Communication Diagram
GLL146632Courtesy of VOLVO CARS OF NORTH AMERICA.

The desired departure time is set using the steering wheel module (SWM) (3/254).

The central electronic module (CEM) (4/56) calculates when the heater needs to start. The heater starts 2 hours and 45 minutes before the set departure time, irrespective of the temperature. A text message is displayed in the driver information module (DIM) (5/1) when the electrical heater is running.

The accessory electronic module (AEM) (4/78) electrically controls when the heater should be switched on and off. The engine block heater must be connected to a wall socket. The accessory electronic module (AEM) activates a relay which closes the switch for a heater element.

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When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • β€’ You smell fuel, burning insulation, or see smoke.
  • β€’ Brakes feel soft, pull hard to one side, or make grinding noises.
  • β€’ The engine overheats, stalls repeatedly, or misfires under load.
  • β€’ You are missing required tools, torque specs, or safe lifting equipment.
  • β€’ You are not confident in the next step or safety outcome.