engine TOYOTA PRIUS 2001 Service Repair Manual

DI±170
± DIAGNOSTICSENGINE
2001 PRIUS (RM778U)
2 Check continuity between terminal CG of DLC3 and body ground.
NG Repair or replace harness or connector.
OK
3 Check for open and short circuit in harness and connector between ECM and
DLC3, and DLC3 and body ground (See page IN±41).
NG Repair or replace harness or connector.
OK
Check and replace ECM (See page IN±41).

FI7012A11860
P±G A/C Control Assembly
A8 E10522
ACTECM
± DIAGNOSTICSENGINE
DI±171
2001 PRIUS (RM778U)
A/C Cut Control Circuit
CIRCUIT DESCRIPTION
This circuit cuts air conditioning operation during vehicle acceleration in order to increase acceleration per-
formance. During acceleration with the vehicle speed at (AT: 25 km/h (16 mph), MT: 40 km/h (25 mph)) or
less, engine speed at (AT: 1,200 rpm, MT:1,600 rpm) or less and throttle valve opening angle at 60° or more,
the A/C magnet switch is turned OFF for several seconds.
WIRING DIAGRAM
INSPECTION PROCEDURE
TOYOTA hand±held tester:
1 Connect the TOYOTA hand±held tester and check operation of air conditioning
cut control.
PREPARATION:
(a) Connect the TOYOTA hand±held tester to the DLC3.
(b) Turn the ignition switch ON and TOYOTA hand±held tester main switch ON.
(c) Start the engine and air conditioning switch ON.
HINT:
A/C magnet clutch is turned ON.
(d) Select the ACTIVE TEST mode on the TOYOTA hand±held tester.
CHECK:
Check operation of A/C magnet clutch cut when air conditioning cut control is operated by the TOYOTA
hand±held tester.
OK:
A/C magnet clutch is turned OFF.
DI7T8±01

A14008
START
(±)
(+)ACT
DI±172
± DIAGNOSTICSENGINE
2001 PRIUS (RM778U)
OK Proceed to next circuit inspection shown on
problem symptom table. (See page DI±22)
NG
2 Check for open and short in harness and connector between ECM and A/C am-
plifier. (See page IN±41)
NG Repair or replace harness or connector.
OK
3 Check voltage between terminal ACT of ECM and body ground.
PREPARATION:
(a) Remove the ECM with connector still connected (See
page SF±62).
(b) Start the engine.
CHECK:
Measure voltage between terminal ACT of ECM connector and
body ground when A/C switch is turned to ON and OFF.
OK:
A/C switch conditionVoltage
ON9 ± 14 V
OFFBelow 1.5 V
NG Check and replace A/C amplifier.
OK
Check and replace ECM. (See page IN±41)

A14008
START
(±)
(+)ACT
± DIAGNOSTICSENGINE
DI±173
2001 PRIUS (RM778U)
OBDII scan tool (excluding TOYOTA hand±held tester):
1 Check voltage between terminal ACT of ECM and body ground.
PREPARATION:
Start the engine.
CHECK:
Measure voltage between terminal ACT of ECM connector and
body ground when A/C switch is turned to ON and OFF.
OK:
A/C switch conditionVoltage
ON9 ± 14 V
OFFBelow 1.5 V
OK Check and repair ECM. (See page IN±41)
NG
2 Check for open and short in harness and connector between ECM and A/C am-
plifier. (See page IN±41)
NG Repair or replace harness or connector.
OK
Check and replace A/C amplifier.

DI82J±02
Prius Problem Check Sheet
Vehicle
Specifications
Please fill in the blanks within bold frame.Name of DealerPerson in Charge at
HeadquartersPerson in Charge
at Dealer
Model CodeOffice
Vehicle Delivery Date
Frame No.
Unit No. etc.
Option . . . :
( ) Navigation (equipped by ( ) MOP ( ) dealer) ( ) Cold climate specification
( ) others( )Problem Occurrence Date
Service Entry Date NHW11±
. .
. .Registration datemiles
. .
Contents of complaint (Status when and before/after occurring in
the order of events as correct as possible)Characteristics of Customer
Gender
Age
Occupation
Vehicle used before
Main use area
Frequency in use
Others times/day or
week or month
Status of engineOthers
Interview Results
( ) Male ( ) Female
suburbs ( ) %
Others ( ) ( ) %
city area ( ) %
mountain area ( ) %
Driving ConditionRoad Condition
Vehicle Condition
Vehicle Speed
km/h
( ) when starting
( ) when according
( ) When
normal driving
( ) when
decelerating
( ) when braking
( ) when shopping
( ) when parking
( ) when turning
( ) when
ABS actuating
( ) others
( )( ) flat road
( ) up hill ( ) down
hill incline of
° /%
distance
km
( ) dry paved road
( ) wet paved road
( ) rough paved road
( ) unpaved road
( ) snowy/frozen
road
( ) bump/curb
( ) others
( )( ) when starting
( ) right after
starting
( ) until min.
after starting
( ) until min.
after starting
of driving
( ) when shopping
system
( ) while shopping
engine
( ) when starting
engine
( ) when revolving
engineHV Battery
indication
( ) 4/4 ( ) 3/4
( ) 2/4 ( ) 1/4
( ) unidentified
Shift position
(indication)
( ) P ( ) R ( ) N
( ) D ( ) B
( ) when operating
"Weather:
A/C status
( ) no indication
( ) unidentified
( ) A/C ( ) FULL
( ) OFF
( ) unidentifiedWarning light
(MIL)
( ) ON ( ) OFF
( ) PS
( ) main battery
( ) HV!
( ) engine
( ) charge
( ) output
control
( ) brake
( ) ABS
( ) others
( )
Temperature:
°C
Brake operation
( ) brake slowly
( ) Brake suddenly
( ) use two pedals
system
Frequency in
occurrence
( ) always
( ) sometimes
( ) only once
Fuel level
( ) segmentsmphOdometer Reading
mph
°F km
± DIAGNOSTICSHYBRID VEHICLE CONTROL SYSTEM
DI±175
2001 PRIUS (RM778U)
CUSTOMER PROBLEM ANALYSIS CHECK

Verification Results of Warning Light
Engine
HV
INF. code
HV battery
Vehicle Verification Results
( ) ON ( ) OFF
( ) engine ( ) HV
( ) HV battery
( ) output control warning light
( ) brake ( ) ABS ( ) charge ( ) PS
( ) others
( )Verification Results of Diagnostic Code
Brake
PS
Vehicle Inspection Results (Verification items, reason to identify/presume the cause parts, etc.)
Replacement Parts
problem parts: No/Yes (Sending date: . . )Duplication Status
( ) always
( ) sometimes
( ) no reproduction
Confirmation Results
After Repair
( ) Normal
( ) reproduction
( ) others ( )
DI±176
± DIAGNOSTICSHYBRID VEHICLE CONTROL SYSTEM
2001 PRIUS (RM778U)

HV ECU±DTC & Information #
INFORMATION 1
INFORMATION 2
INFORMATION 3
INFORMATION 4
INFORMATION 5
INFORMATION 1
INFORMATION 2
INFORMATION 3
INFORMATION 4
INFORMATION 5
INFORMATION 1
INFORMATION 2
INFORMATION 3
INFORMATION 4
INFORMATION 5
INFORMATION 1
INFORMATION 2
INFORMATION 3
INFORMATION 4
INFORMATION 5
HV ECU±Information & Freezed frame data
MG1 REV
MG2 REV
MG1 TORQ
MG2 TORQ
POWER RQST
ENGINE SPD
MCYL CTRL POWER
SOC
WOUT CTRL POWER
WIN CTRL POWER
DRIVE CONDITION
INVERT TEMP ± MG1
INVERT TEMP ± MG2
MG1 TEMP
MG2 TEMP
PWR RESOURCE VM
PWR RESOURCE IB
SHIFT SENSOR 1
ACC SENSOR MAIN
ENG STOP RQST
IDLING REQUEST
ENGINE FUEL CUTrpm
rpm
rpm N´m
NmW
W
W%
( °C)
V
V A
Yes / No
Yes / No
Yes / NoHV BATT CH RQST
HCAC ABSRT RQST
ENG WARM UP RQT
STOP SW COND
CRUISE CONTROL
AUX. BATT V
EXCLUSIVE INFO1
EXCLUSIVE INFO2
EXCLUSIVE INFO3
EXCLUSIVE INFO4
EXCLUSIVE INFO5
EXCLUSIVE INFO6
LOAD CONDITION
DRIVING PATTEN1
DRIVING PATTEN2
DRIVING PATTEN3
IG OFF IN DRVIN
SG B IN REDUCIN
SG N IN REDUC/P
STEP ACC&BRAKE
IG OFF TIME
OCCURRENCE ORDERV Yes / No
Yes / No
Yes / No
Yes / No
Yes / No
Yes / No
Yes / No
Yes / No
Yes / No MG1 / MG2
min
± DTC
DTC
DTC
DTC
N´m
INFORMATION
°F
( °C) °F
( °C) °F
( °C) °F DI±180
± DIAGNOSTICSHYBRID VEHICLE CONTROL SYSTEM
2001 PRIUS (RM778U)

Engine ECU
TROUBLE CODE
CALC LOAD
ENGINE SPD
COOLANT TEMP
INTAKE AIR
VEHICLE SPD
SHORT FT #1
LOND FT #1
FUEL SYS #1
FUEL SYS #2
ENG RUN TIME
BATTERY
INJECTOR
INJ VOL FB
FEL FB COEF
A/F LEARN
PURGE LEARN
KCS FEEDBACK
REQ ENQ TORQ
RAM MONITOR
ENG RUN SIG
ACC RACING SIG
ENG WARM UP SIG
ENG RUN PERM
FC STATUS
ENG STP LIMIT%
rpm
%
%
V
ms
%
%
degree
KW
ON / OFF
ON / OFF
ON / OFF
EMPS ECU
TROUBLE CODE
TRQ1
TRQ2
WRR
WRL
MOTOR ACTUAL
COMMAND VALUE
STR ANGL VEL
THERMISTOR TEMP
PIG SUPPLY
IG SUPPLY
TRQ1 ZERO VAL
TRQ2 ZERO VALV
V
V V V A
A
deg/s
ON / OFF°F ( °C)
°F ( °C)
mph ( km/h)
mph ( km/h)
mph ( km/h)
°F ( °C) DI±186
± DIAGNOSTICSHYBRID VEHICLE CONTROL SYSTEM
2001 PRIUS (RM778U)

± DIAGNOSTICSHYBRID VEHICLE CONTROL SYSTEM
DI±189
2001 PRIUS (RM778U)
179Impossible to drive
180Impossible to drive
181Impossible to drive
182Impossible to drive
183Impossible to drive
184Impossible to drive
185Impossible to drive
186Impossible to drive
187Impossible to drive
188Limited driving
189Limited driving
190Limited driving
191Limited driving
192Limited driving
P3100193HV ECU MalfunctionLimited drivingP3100
194
HV ECU Malfunction
Limited driving
195Limited driving
196Limited driving
197Limited driving
198Normal driving
199Limited driving
200Limited driving
201Limited driving
202Limited driving
203Limited driving
271Normal driving
310Limited driving
392Impossible to drive
393Impossible to drive
204Limited driving
P3101205Engine System MalfunctionLimited drivingP3101
238
Engine System Malfunction
Limited driving
206Limited driving
P3105207Battery ECU Communication
Circuit MalfunctionLimited drivingP3105
208Circuit MalfunctionLimited driving
209Limited driving
210Limited driving
P3106211ECM Communication Circuit
MalfunctionLimited drivingP3106
212MalfunctionLimited driving
394Limited driving
213Normal driving
P3107214Airbag ECU Communication
Circuit MalfunctionNormal drivingP3107
215Circuit MalfunctionNormal driving
P3108216A/C Amplifier CommunicationNormal drivingP3108217
A/C Am lifier Communication
Circuit MalfunctionNormal driving

± DIAGNOSTICSHYBRID VEHICLE CONTROL SYSTEM
DI±193
2001 PRIUS (RM778U)
5. CHECK FOR INTERMITTENT PROBLEMS
(a) Perform a simulation test (See page IN±41).
In the simulation test, reproduce the driving condition at the trouble occurrence according to the cus-
tomer 's comments and freeze frame data recorded with DTC, such as an opening angle of the acceler-
ator pedal, SOC, engine coolant temperature, engine rpm, and MG/1MG2 rpm and torque.
(b) Check the connector and terminal (See page IN±41).
(c) Handle the connector (See page IN±41).
6. TOYOTA HAND±HELD TESTER DISPLAY ITEMS
TOYOTA Hand±held tester displayMeasurement Item
1 BEF LATST ORNumber of operation of 1 trip before last
1 BEF LATST TRPNumber of trips before last
2 BEF LATST ORNumber of operation 2 trips before last
2 BEF LATST TRPNumber of trips 2 before last
ABNML CON BR±HVCommunication malfunction between HV ECU and brake
ACC SENSOR MAINMain accelerator sensor
ACC SENSOR SUBSub accelerator sensor
ACC TENT TRBLETentative trouble of accelerator
ACC THROTTLEAccelerator throttle
ACCEL MODEHistory of acceleration and reduction
AIR CON REQUESTAir conditioner request
AUX. BATT LOWAuxiliary battery becomes week
AUX. BATT VVoltage of auxiliary battery
BATT HIGH TEMPTemperature of the battery is too high
BATT HIGH VOLTVoltage of the battery is too high
BATT LOW BOLTVoltage of the battery is low
BATT OVER LOADBattery is overloaded
BATT SAVE RQSTRequest to save the main battery
BATTERY FULLBattery full
BRAKE TORQBrake torque
CELL TEMP±MAXHighest temperature of all battery cells
CELL TEMP±MINLowest temperature of all battery cells
CHG RESTRICTIONCharge restriction
COOLANT TEMPWater temperature
CRUISE CONTROLCondition of the cruise control
DC/DC CONV STOPDC/DC converter stop signal
DC/DC CONV STOPFactors causing DC/DC converter to stop
DC/DC STOP FACTDC/DC converter has stopped at least once
DC/DC V UNSETDC/DC voltage is unsettled
DCHG RQST SOCDischarge request to adjust SOC
DISCHAG INHIBITBattery is inhibited to discharge