2001 TOYOTA PRIUS oil temperature

2001 PRIUS (EWD414U)
E
RELAY
Basically, an electrically operated
switch which may be normally
closed (1) or open (2).
Current flow through a small coil
creates a magnetic field which either
opens or closes an attached switch.
1. NORMALLY
CLOSED
2. NORMALLY
OPEN
SWITCH, MANUAL
Opens and closes
iitth b
SPEAKER
An electromechanical device which
creates sound waves from current
flow.
RELAY, DOUBLE THROW
A relay which passes current
through one set of contacts or the
other.
circuits, thereby
stopping (1) or
allowing (2) current
flow.1. NORMALLY
OPEN
2. NORMALLY
CLOSED
RESISTOR
An electrical component with a fixed
resistance, placed in a circuit to
reduce voltage to a specific value.SWITCH, DOUBLE THROW
A switch which continuously passes
current through one set of contacts
or the other.
RESISTOR, TAPPED
A resistor which supplies two or
more different non adjustable
resistance values.SWITCH, IGNITION
A key operated switch with several
positions which allows various
circuits, particularly the primary
ignition circuit, to become
operational.
RESISTOR, VARIABLE or RHEOSTAT
A controllable resistor with a variable
rate of resistance.
Also called a potentiometer or
rheostat.
SENSOR (Thermistor)
A resistor which varies its resistance
with temperature.SWITCH, WIPER PARK
Automatically returns wipers to the
stop position when the wiper switch
is turned off.
(Reed Switch Type)
SENSOR, SPEED
Uses magnetic impulses to open
and close a switch to create a signal
for activation of other components.TRANSISTOR
A solidstate device typically used as
an electronic relay; stops or passes
current depending on the voltage
applied at ºbaseº.
SHORT PIN
Used to provide an unbroken
connection within a junction block.WIRES
Wires are always drawn as
straight lines on wiring
diagrams.
Crossed wires (1) without a
black dot at the junction are
tj i d
(1) NOT
CONNECTED
SOLENOID
An electromagnetic coil which forms
a magnetic field when current flows,
to move a plunger, etc.
j
not joined;
crossed wires (2) with a
black dot or octagonal ( )
mark at the junction are
spliced (joined)
connections.
(2) SPLICED

ENGINE ± 1NZ-FXE ENGINE
182EG25
Engine Load
Full Load Performance
Range 4Range 5
Range 3
Range 2
Range 1Engine Speed
TDC
EXIN
BDCLatest
timing
To retard
side
IN
EX
To advance
side
EX IN71
In proportion to the engine speed, intake air volume, throttle position and water temperature, the ECM cal-
culates an optimal valve timing under each driving condition and control the camshaft timing oil control
valve. In addition, ECM uses signal from the camshaft position sensor and the crankshaft position sensor
to detect the actual valve timing, thus performing feedback control to achieve the target valve timing.

Operation During Various Driving Condition (Conceptual Diagram) 
Operation StateRangeValve TimingObjectiveEffect
During Idling1
182EG26
Eliminating overlap to
reduce blow back to the
intake sideStabilized
idling rpm
Better fuel
economy
At Light Load2
182EG27
Decreasing overlap to
eliminate blow back to
the intake sideEnsured
engine
stability
At Medium
load3
182EG28
Increasing overlap to
increase internal EGR for
pumping loss elimination
Better fuel
economy
Improved
emission
control

THS (TOYOTA HYBRID SYSTEM)
HV ECUG-SDOWNInverter
(for MG1)
MG1
MG2
M-UU, VU, WUSwitching Signal
Switching Signal
G-SIN, COS
M-SIN, COS
Inverter
(for MG2) G-UU, VU, WU
M-SDOWN
G-REF
M-REF
30
5. Inverter Control (for MG1, MG2)
The HV ECU transmits a signal to the power transistor in the inverter (G-UU, VU, WU, M-UU, VU, WU)
for switching the U, V, W phase of the stator coil of MG1 and MG2, based on the rotor position information
sent from MG1, 2 (G-SIN, COS, M-SIN, COS) and the SOC of the HV battery sent from the battery ECU.
When shutting down the current to MG1, 2, a signal is sent to the inverter from the HV ECU (G-SDOWN,
M-SDOWN).
Clutchless System
A clutchless system has been adopted to keep the front wheels and MG2 linked mechanically via gears and
a chain. To disengage the drive force in the neutral position, the N position signal from the shift position
sensor turns OFF all the power transistors in the inverter (which connects the MG1 and the MG2) in order
to shut down the operation of the MG1 and the MG2, thus rendering the drive force at the wheels to zero.
In this state, even if the engine is running, the MG1 merely freewheels in the no-load state.
Therefore, if the vehicle is allowed to operate continuously in the N position in a stationary state such as
in heavy traffic, the SOC (state of charge) of the HV battery will continue to drop lower and lower.
6. Battery ECU
The SOC, temperature and the voltage of HV battery are detected by the battery ECU, and this information
is sent to HV ECU.

BODY ELECTRICAL ± AIR CONDITIONING 152
AIR CONDITIONING
DESCRIPTION
The air conditioning system in the Prius has the following features:
Both heating and demisting performances are realized by adopting performances are realized by adopting
the 2-way flow heater type air conditioning unit.
A multi-tank, super-slim structure evaporator has been adopted.
An automatic air conditioning system which provides enhanced air conditioning comfort according to the
occupant's senses has been adopted.
A semi-center location air conditioning unit, in which the evaporator and heater core are placed in the ve-
hicle's longitudinal direction, has been adopted.
A compact, high-performance scroll compressor with oil separator has been adopted.
The heat exchange efficiency has been improved through the adoption of the sub-cool condenser.
This condenser is integrated with the radiator to minimize the space they occupy in the engine compart-
ment.
A compact, lightweight, and highly efficient straight flow (full-path flow) aluminium heater core has been
adopted.
This heater core is integrated with a PTC (Positive Temperature Coefficient) heater, which excels in heat-
ing performance.
PTC heaters have been provided in the air duct at the footwell outlet in front of the air conditioning unit.
However, air conditioning without the PTC heaters is offered as an option on the U.S.A. models.
An electrical water pump with a bypass valve that provides a stable heater performance even if the engine
is stopped due to a function of the THS (TOYOTA Hybrid System) has been adopted.
A clean air filter that excels in removing pollen and dust is standard equipment.

EM9891
± DIAGNOSTICSENGINE
DI±9
2001 PRIUS (RM778U)
3 Check air filter.
PREPARATION:
Remove the air filter.
CHECK:
Visual check that the air filter is not dirty or excessive oily.
HINT:
If necessary, clean the air filter with compressed air. First blow
from inside thoroughly, then blow from outside of the air filter.
NG Repair or replace.
OK
4 Check engine idle speed.
PREPARATION:
(a) Warm up engine to normal operating temperature.
(b) Switch off all accessories.
(c) Switch off A/C.
(d) Shift transmission into P position.
(e) Connect the TOYOTA hand±held tester or OBDII scan tool to DLC3 on the vehicle.
(f) Transit to inspection mode.
CHECK:
Use CURRENT DATA to check the idle speed.
OK:
Idle speed: 950 ± 1,050 rpm
NG Proceed to problem symptoms table on page
DI±22.
OK

A04438A13924A14466
TC
CG
A14060
DI±10
± DIAGNOSTICSENGINE
2001 PRIUS (RM778U)
5 Check ignition timing.
PREPARATION:
(a) Warm up engine to normal operating temperature.
(b) Shift transmission into P position.
(c) Keep the engine speed at idle.
(d) Using SST, connect terminals TE1 and E1 of DLC1.
SST 09843±18020
(e) Using a timing light, connect the tester to the ignition coil
connector wire (See page EM±11).
(f) Transit to inspection mode.
CHECK:
Check ignition timing.
OK:
Ignition timing: 7 ± 15° BTDC at idle
NG Proceed to page IG±1 and continue to trouble-
shoot.
OK
Proceed to problem symptoms table on page
DI±22.
6 Check fuel pressure.
PREPARATION:
(a) Be sure that enough fuel is in the tank.
(b) Connect the TOYOTA hand±held tester to the DLC3.
(c) Turn the ignition switch ON and push the TOYOTA hand±
held tester main switch ON.
(d) Use the ACTIVE TEST mode to operate the fuel pump.
(e) Please refer to the TOYOTA hand±held tester operator's
manual for further details.
(f) If you have no TOYOTA hand±held tester, connect the
positive (+) and negative (±) leads from the battery to the
fuel pump connector (See page SF±6).
CHECK:
Check for fuel pressure in the fuel inlet hose when it is pinched
off.
HINT:
At this time, you will hear a fuel flowing noise.

DI±194
± DIAGNOSTICSHYBRID VEHICLE CONTROL SYSTEM
2001 PRIUS (RM778U)
0: When engine is stopped
1: When stopping engine
2: When starting engine
DRIVE CONDITION3: When cranking engine or engine is operatingDRIVE CONDITION
4: While generating power or load driving
5: ±
6: While racing engine in P position
DRIVING PATTEN1History of driving pattern 1
DRIVING PATTEN2History of driving pattern 2
DRIVING PATTEN3History of driving pattern 3
DRIVING PATTERNHIstory of driving
ECU TYPEECU type
ENG INDPDET RQFactors causing engine to run independently
ENG STOP RQSTEngine stop request
ENG STP INHIBITEngine stop inhibition
ENG WARM UP RQTEngine warming up request
ENGINE FUEL CUTEngine fuel cut
ENGINE SPDEngine speed
EXCLUSIVE INFO1Exclusive information 1
EXCLUSIVE INFO2Exclusive information 2
EXCLUSIVE INFO3Exclusive information 3
EXCLUSIVE INFO4Exclusive information 4
EXCLUSIVE INFO5Exclusive information 5
EXCLUSIVE INFO6Exclusive information 6
FUEL SHORTAGELow fuel
HCAC ABSRT RQSTHCAC OBD request
HV BATT CH RQSTRequest from HV ECU to charge the battery
HV ECU INTERMITTENTHV ECU intermittent problems
IDLING REQUESTEngine idling request
IG OFF IN DRVINTurning IG OFF while driving the car
IG OFF TIMEIG OFF time
ILK OPERATIONInterlock operation
INFORMATION 1±5Information code
INPUT V LOWInput voltage is too low
INPUT V OVERInput voltage is too high
INTAKE AIRIntake air temperature
INVERT TEMP±MG1Temperature of inverter MG1
INVERT TEMP±MG2Temperature of inverter MG2
LATEST OPERLatest number of operation
LATEST TRIPLatest number of trips (IG ON±OFF)
LOAD CONDITIONIndicating which of MG1 or MG2 the vehicle uses more
MAIN BATT LOWSOC of main battery becomes low
MCYL CTRL POWERTorque for controlling oil pressure of master cylinder
MG1 TEMP HIGHTemperature MG1 is too high
MG2 TEMP HIGHTemperature MG2 is too high
MG1 CURRENT VElectric current of MG1 V phase

DI±682
± DIAGNOSTICSCOMBINATION METER SYSTEM
2001 PRIUS (RM778U)
4 Check the corresponding switch or ECU.
CHECK:
Check if the corresponding switch or ECU is normal or not.
Ye s
No Corresponding switch or ECU faulty.
Combination meter ECU faulty.
*:
Multiplex communication inputSingle Communication Input
OPEN DOOR WARNINGHI±BEAM INDICATOR
BRAKE WARNINGTURN SIGNAL IND
OUTPUT CONTROL INDICATORSRS WARNING
SHIFT POSITION INDICATORABS WARNING
SEAT BELT WARNINGCHECK ENGINE WARNING
READY INDICATOR
WATER TEMPERATURE WARNING
OIL PRESSURE WARNING
CRUISE CONTROL INDICATOR
TAIL INDICATOR
DISCHARGE WARNING