IX - ADDITIONAL HEATINGAs the engine is highly efficient, a system is required to assist the rise in temperature in the passenger compartment in cold climates.
The passenger compartment temperature rise assistance system is controlled by the built-in systems interface and operated by the injection ECU.
2 devices are used depending on the marketing country:
• several thermoplungers (electrical resistors) located in the coolant circuit of the heater matrix,
• an additional fuel powered heater located in the front left hand wheel arch (for vehicles in very cold countries).
A - DIAGRAMCapture d’écran 2012-01-30 à 18.31.01.png
Key:
A - VAN network
B - CAN network
C - Wire connection
(1220) Coolant temperature sensor.
(1320) Injection ECU.
(6415) Exterior air temperature sensor.
(8098) Electrical resistors.
(1190) Additional heater.
(9050) Front RH door station.
(BSI1) Built-in systems interface.
The built-in systems interface authorises operation of these additional heating systems depending on the following parameters:
• coolant temperature,
• exterior air temperature.
B - PRESENTATION OF THE ADDITIONAL HEATING SYSTEMS1 - Electrical resistors Capture d’écran 2012-01-30 à 18.30.31.png
Assembly with 3 relays and 3 resistors
1320 - Injection ECU
8098 - Electrical resistors
BSI1 - Built-in systems interface
The resistors can each supply a power of 330 watts.
This assembly allows heating powers of 330, 660 or 990 watts.
2 - Additional heater The wiring only allows one heating power to be obtained.
The additional heater is controlled by an integrated ECU.
C - CONTROL OF THE PASSENGER COMPARTMENT HEATING SYSTEMS
The additional heater is switched on in the following cases:
• low passenger compartment temperature (specific curve),
• when the engine operating conditions so allow.
D - WORKING OUT THE ADDITIONAL HEATING REQUIREMENTSCapture d’écran 2012-01-30 à 18.30.43.png
ta - Exterior air temperature
te - Coolant temperature
a - Example 1
b - Example 2
(outside shaded area) heating authorisation zone.
The BSI determines the passenger compartment heating requirement when the engine is started depending on the exterior air temperature and the coolant temperature.
Example 1:
• coolant temperature = 40°C,
• exterior temperature = 10°C,
• the temperature conditions are within the additional heating operating zone.
Example 2:
• coolant temperature = 70°C,
• exterior temperature= 10°C.
• the temperature conditions are outside the additional heating operating zone.
E - OPERATIONThe BSI determines the passenger compartment heating requirement when the engine is started depending on the exterior air temperature and the coolant temperature.
The built-in systems interface operates the additional heater in the following conditions:
• engine operating for more than 60 seconds,
• engine speed above 700 rpm,
• battery voltage greater than 12 volts (positive electrical balance),
• coolant temperature above 40°C.
The built-in systems interface controls the heater stages progressively:
• first stage,
• second stage,
• second stage and first stage.
The additional heating is switched off when the temperature conditions so allow (curve).