Fiat STILO 1.9 JTD 8v da 01/04 – ADDITIONAL HEATER – – WIRING DIAGRAM, LOCATION COMPONENTS, OPERATIONAL DESCRIPTION – WIRING DIAGRAM, LOCATION COMPONENTS, OPERATIONAL DESCRIPTION

Wiring diagram - ADDITIONAL HEATER - Fiat STILO 1.9 JTD 8v da 01/04

ADDITIONAL HEATER - WIRING DIAGRAM Fiat STILO 1.9 JTD 8v da 01/04

Get access to all wiring diagrams of the car

Components - ADDITIONAL HEATER - Fiat STILO 1.9 JTD 8v da 01/04

Component code	Name	Assembly reference
B1	Engine compartment junction unit
B38	Additional heater fuse	-
B99	Maxifuse box on battery
I95	Additional heater safety switch	-
J36	Additional heater relay	-
J37	Additional heater relay - 2	-
J37	Additional heater relay -2	-
K79	Air temperature sensor (additional heater)(	-
K79	Air temperature sensor (additional heater)()	-
M70	Climate control system control unit
N85	Passenger compartment ventilation fan	5040C 3363005
O25	Additional heater resistor	-

Location of components - ADDITIONAL HEATER - Fiat STILO 1.9 JTD 8v da 01/04

ADDITIONAL HEATER - LOCATION OF COMPONENTS Fiat STILO 1.9 JTD 8v da 01/04

Get access to all wiring diagrams of the car

Components - ADDITIONAL HEATER - Fiat STILO 1.9 JTD 8v da 01/04

Component code	Name	Assembly reference
B1	Engine compartment junction unit
B38	Additional heater fuse	-
B99	Maxifuse box on battery
I95	Additional heater safety switch	-
J36	Additional heater relay	-
J37	Additional heater relay - 2	-
J37	Additional heater relay -2	-
K79	Air temperature sensor (additional heater)(	-
K79	Air temperature sensor (additional heater)()	-
M70	Climate control system control unit
N85	Passenger compartment ventilation fan	5040C 3363005
O25	Additional heater resistor	-

Description - ADDITIONAL HEATER - Fiat STILO 1.9 JTD 8v da 01/04

The climate control via the heater unit is insufficient when the engine is cold, especially in Diesel engines which are slow to warm up.These engines may optionally be fitted with a supplementary heater system. This remains active from the moment when the engine is turned on until a certain temperature is reached.The system consists of an additional heater, located in the heater unit: the device contains three resistances (PTC).The operation of the resistances is controlled by a specific control unit - connected via the CAN network to the car''s other nodes - which drives only one, or two or three, thus providing progressive heating.This control logic depends on:the temperature of the engine coolant;the electrical power available (in effect, the battery voltage is checked)the engine speed (which should be above a pre-set value).The supply of one, two or three resistances is controlled by two relays located on the heater unit:1. Level: activated by the first relay;2. Level: activated by the second relay;3. Level: activated by both relays.This supply is interrupted in the case of overtemperatures, via a specific safety switch.Also, when the heater is on, the switching on of the fan is controlled.For more details.The supply line is protected by a specific maxifuse and a bridge fuse.

Functional description - ADDITIONAL HEATER - Fiat STILO 1.9 JTD 8v da 01/04

The relay J36 controls the engagement of the first additional heater coilThe relay is supplied from the fuse B38 .The relay J37 controls the engagement of the other two additional heater coils. The supply for relay arrives from the line for maxifuse PTC2, located on the battery, connector B99 .the ignition (INT/A) protected by fuse F49 of the junction unit under the dashboard B2. This supply is cut off in the case of overheating, via the safety switch l95 .Control unit M75 controls device operation: it is supplied by an igntiion-operated line (INT) protected by fuse F49 of underfacia control unit B2, and connected via the CAN line to Body Computer M1and the other network nodes.The climate control unit M75 sends the enabling signal for engaging the first resistance O25A to excite relay J36 and a signal to activate the two coils O25B at relay J36. Another dedicated signal controls activation of the first speed of air fan N85 , supplied by ignition-operated line (INT/A) of relay T8 and dedicated fuse F8 of engine bay control unit B1 - it is operated at the first speed in any case if the supplementary heating device is on..