Knock Control - Alfa Romeo 159 Training Material

ENGINE
I
NPUT PARAMETERS
E
LECTRICAL QUANTITY
Engine speed sensor
Frequency on pins A55
and A40
Pre-cat lambda sensors
Voltage signal on pins: K-
77 and K-79
Post-cat lambda sensors
Voltage signal on pins: K-
75 and K-53
Air flow meter
Voltage on pin A-12

Knock control

The ECU can delay ignition selectively on the cylinder where this is required according to the combination of values
received by the knock and timing sensors and:
reduces ignition advance in 3° steps to a maximum of 9°;
updates the threshold to account for background noise and engine ageing.
The ECU during acceleration uses a higher threshold to increase engine noise.
When knock disappears, the ECU will increase ignition advance in 0.75° steps to total recovery.
The ECU self-adaptive function:
stores the continuously repeated advance reductions
updates mapping to the various conditions in which the engine operated.
RECOVERY PROCEDURE
A variable spark delay is implemented according to the engine speed and temperature in the event of failure to the
timing sensor or knock sensor. The maximum ignition delay is always less than 9° of the engine.
Traccia Didattica Alfa 159-en-ridotta
ALFA 159 TRAINING MATERIAL
C
ONTROLLER
L
OGIC
MED 7.6.1
The ECU controls the amount of
injected fuel according to the
signals from the sensors and the
mapped values and:
•
controls the pressure
regulator
•
adapts injector injection times
•
adapts spark advance
116/318
Fiat Auto S.p.A.
After Sales Training
O
UTPUT PARAMETERS
E
LECTRICAL QUANTITY
Pressure regulator
Control voltage on pin: A-
20
Injectors
Voltage to pins:
A-50, A-49; A-47, A-48;
A-32, A-33; A-35, A-34
Ignition coils
Voltage disconnected from
pins
A-46; A-31; A-01; A-16
© 2004 Fiat Auto S.p.A. - All rights reserved