Description
(1) motorised throttle housing
"a" 6-way brown connector
Make: MAGNETI MARELLI
Role
Role of the motorised butterfly housing
- Dose the quantity of air admitted in the cylinders
- Create a vacuum in the air inlet manifold, necessary for the intake of the petrol vapours originating from the canister and of the recirculated oil vapours and for the braking assistance
NoteA dual sensor incorporated in the motorised butterfly housing enables the engine management ECU to determine the exact position of the air butterfly
Function
"A" position of the butterfly at rest (ignition off) or "limp home" position in the event of a failure
"B" position of the gas butterfly with the ignition on or at idle
"C" position of the butterfly at full load
"b" force of the butterfly motor
"c" force of the spring
With the ignition off, the "limp home" spring holds the butterfly open (position "A")
When the ignition is switched on, the engine management ECU controls the butterfly to the idle position, countering the force of the "limp home" spring (position "B")
When the engine is idling the throttle butterfly moves to supply the airflow required by the engine
With the engine under full load, the throttle butterfly is at its maximum limit so as to provide the maximum of air that the engine needs (position "C")
The position of the throttle is monitored by the engine management ECU (potentiometer incorporated in the butterfly unit)
The butterfly minimum and maximum limits are recalculated at each initialisation with the aid of two position sensors
The engine management ECU cuts off the supply to the butterfly housing if certain faults are present
Once a fault is detected, the butterfly is placed in the "limp home" position to allow the user to continue driving in downgrade mode
The air flow in "limp home" is 21 kg/h
WarningDo not attempt to adjust or dismantle a butterfly unit (safety)
Electrical features
"D" motorised throttle control (in volts)
"E" Motorised throttle angle (in degrees)
"d" Sensor 1 signal
"e" Sensor 2 signal
| Motorised throttle angle | Sensor 1 signal | Sensor 2 signal |
|---|---|---|
| 0° | 0,5 V | 4,5 V |
| 10° | 0,97 V | 4,3 V |
| 20° | 1,45 V | 3,83 V |
| 30° | 1,92 V | 3,35 V |
| 40° | 2,4 V | 2,88 V |
| 50° | 2,88 V | 2,4 V |
| 60° | 3,35 V | 1,92 V |
| 70° | 3,83 V | 1,45 V |
| 80° | 4,3 V | 0,97 V |
| 85° | 4,5 V | 0,5 V |
| designation | minimum tolerance | nominal value | maximum tolerance |
|---|---|---|---|
| motorised throttle supply voltage | 10,5 V | 13,5 V | 16 V |
| motorised throttle supply current | - | 5,5A | - |
| Sensor supply voltage | 4,75 V | 5 V | 5,25 V |
| sensors supply current | - | 20 mA | - |
| resistance of the motorised throttle at 25°C | 1,35 ohm | 1,5 ohm | 1,65 ohm |
| channel number | allocation of channels of connector |
|---|---|
| 1 | positive control |
| 2 | negative control |
| 3 | earth |
| 4 | 5V supply |
| 5 | 1 signal |
| 6 | 2 signal |
Programming/initialisation
It is necessary to determine regulating flap positions after replacing the injection ecu or the throttle housing