Climate Control System; Climate Control System Overview; Manual Climate Control System; Structure - Alfa Romeo 159 Training Material

ELECTRICAL
SYSTEM

10. CLIMATE CONTROL SYSTEM

The vehicle may be equipped with one of three types of climate control system configurations:
One-zone manual
Two-zone automatic
Three-zone automatic

10.1 CLIMATE CONTROL SYSTEM OVERVIEW

The climate control system implements a variable displacement Zexel-Valeo compressor and a block expansion
valve. The effective capacity of regulating gas quantities in the evaporator achieved by these two elements has
eliminated the need to use a frost sensor. The system contains 550
3 3
150 cm (+15/-30 cm
A pollen filter accessible through the flap (2) shown in the figure on page 3 is fitted in all versions. Specifically, a
traditional filter is fitted in one-zone versions while a two-layer paper filter containing a chemical substance capable of
withholding also finest dust and particulate is fitted in two and three-zone versions.

10.2 MANUAL CLIMATE CONTROL SYSTEM

The manual climate control system is a one-zone device. The classical control panel that integrates the NCL ECU is
shown in the figure below:

10.2.1 Structure

The air mixing (17), air distribution (18) and air recirculation (16) controls are transmitted by stepper motors controlled
directly by the ECU (see figure on page 3 and wiring diagram on page 5). The climate control fan speed is controlled
by a classic resistive splitter (20) fitted in the air manifold.

10.2.2 Operation

The manual climate control system can be used to adjust the temperature and air flows let into the passenger
compartment using buttons and knobs. The following parameters/functions can be adjustment manually:
Temperature
Air distribution (five positions)
Fan speed
Compressor enabling
Recirculation
Defrosting/demisting

10.3 SUPPLEMENTARY HEATER

Diesel versions fit a supplementary heater for warming up the passenger compartment faster while the engine is
warming up. The device consists of a plate (9) split into two sections, each of which integrates a PTC that heats up
when powered. The plate is positioned inside a specific compartment (5) in the body of the heater unit and is invested
by the air let in from the outside.
10.3.1 Operation
The PTCs are powered by two relays in the unit (24) and are controlled directly by the NCL ECU when:
The engine temperature is cooler than 65°C
Traccia Didattica Alfa 159-en-ridotta.doc
ALFA 159 TRAINING MATERIAL
) of ZXL100PG oil is used.
40 grams of R134 gas.
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