Toyota COMPUTER-CONTROLLED SYSTEM Training Manual page 136

OTHER CONTROL SYSTEMS - Supercharger Control System, EHPS Control Syste m
SUPERCHARGER CONTROL
SYSTEM
The Engine ECU controls the supercharger relay,
thus turning the supercharger magnetic clutch on
and off. It also controls supercharger operation
by controlling the supercharger bypass valve
(stepper motor type) .
In addition, the ECU controls the ACV to reduce
supercharger oil consumption .
Suspercharger bypas s
valve (stepper motor type)
Engine EC U
AB,, A8 z
+B
AC V
(Air control
valvel
Intercooler
AB3, AB 4
Supercharge r
magnetic clutc h
rela y
Supercharge r
+ B
Supercharger magnetic
clutch ACV
D
0
REFERRENCE
In previous models, VSV and ABV (air bypass
valve) have been used instead of a super-
charger bypass valve .
For a deteiled explanation of the construction
and operation of the supercharger, see Step 3,
vol . 2 (Turbocharger and Supercharger) .
SM C
Drive pully
EHPS (ELECTRO-HYDRAULIC
POWER STEERING) CONTROL
SYSTE M
In vehicles equipped with the EHPS, when the
engine coolant temperature or the engine speed
is very low, the load on the alternator is
increased when the vane pump motor of the
EHPS is driven . This condition makes it easier for
poor engine startability or engine stalling to
occur . To prevent this, the vane pump motor is
stopped during cold starting or when the engine
speed is extremely low .
PS ECU
Engine EC U
OHP 90
REFERENCE
EHPS is a type of power steering in which the
vane pump is d rive n by an electric motor .
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