Additional Heater (Diesel Engines Only)

WARNING: This page does not describe the selected car, but rather 8 other vehicles, including the 2006 Volvo S80, 2005 Volvo S80, 2004 Volvo S80, 2003 Volvo S80, and 2002 Volvo S80. However, it is still accessible from the selected car via links, so may be relevant.

Fig 1: Additional Heater And Parking Heater

Courtesy of VOLVO CARS OF NORTH AMERICA.

Control of the additional heater on cars with standard (STD) and manual climate control (MCC)

The climate control module sends a request to the combustion preheater module that the additional heater should start. The central electronic module determines whether start is possible. The combustion preheater module then receives a signal from the central electronic module to start the heater.

Certain conditions must be met before the heater can start. These are:

Outside temperature < +8 °C (The heater stops at 12 °C)
Engine running
Quantity of fuel >4 liters
No diagnostic trouble codes (DTCs) stored in the central electronic module that will prevent starting
Airbag not deployed.

The heater makes three start attempts. If these fail a diagnostic trouble code (DTC) is stored in the central electronic module and a warning message is displayed in the combined instrument panel (driver information module). If the conditions change the central electronic module requests that the heater is stopped.

Control of the additional heater on cars with electronic climate control (ECC)

In cars with climate control the additional heater is activated when required. In addition to the above conditions, the climate control module also takes the outside temperature, engine coolant temperature (ECT) and the temperature selected into account before a request for the heater to start is made.