Audi Q7 e-tron quattro 4M - Page 43

43
Auxiliary hydraulic pump 1 for gear oil V475
The auxiliary hydraulic pump V475 is capable of conveying ATF on
3output levels within an ATF temperature range from 0°C to
125°C. The pump communicates with the automatic gearbox
control unit J217 via a LIN bus line.
The ignition is turned on by pressing the "START ENGINE STOP"
button, and the gearbox control unit instructs the pump via the
LIN bus to convey ATF on the lowest output level. If the selector
lever is engaged in D or R, the pump receives the instruction to
convey ATF on the highest output level. The auxiliary hydraulic
pump ensures the supply of ATF. This aids disengagement of the
parking lock and allows deceleration-free start-up.
If the mechanically driven ATF pump reaches the required speed
and is capable of supplying system pressure by itself, the auxiliary
hydraulic pump receives the instruction via LIN bus to stop convey-
ing ATF. Communciation between the pump and the gearbox
control unit is maintained via the LIN bus line.
The pump electronics of the auxiliary hydraulic pump V475 signal
the condition of the pump to the gearbox control unit. There is no
pressure sensor. In addition, the pump electronics diagnose
electrical faults and cyclically confirm to the gearbox control unit
via the LIN bus the supply of voltage through terminal 30. Any
irregularities which occur are indicated to the gearbox control unit.
Depending on the type of irregularity, an entry is made in the event
memory of the gearbox control unit.
Actuator diagnostics can be performed using the diagnostic tester.
Basically, it is possible to update the pump software. However, this
function will not be available at the time of market launch.
If the temperature is outside limits or if the auxiliary hydraulic
pump V475 fails, ATF is supplied by the mechanically driven ATF
pump only. The ATF pump is driven by the e-machine.
649_082
649_081
Auxiliary hydraulic pump 1 for gear oil
V475
Pump electronics integrated
in the housing
Ground contact for voltage supply
Terminal 30,
positive contact to voltage supply
LIN bus connector
Brushless DC motor
G-rotor pump,
of pump rotor is press-fitted onto the rotor shaft of the DC motor.
Non-return valve,
maintains the oil pressure inside the gearbox when the auxiliary
hydraulic pump V475 is stationary.
Intake duct from ATF suction filter
Pressure connection
Rotor DC motor
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