engine TOYOTA PRIUS 2001 Service Repair Manual

DI7S2±01
DI±874
± DIAGNOSTICSAIR CONDITIONING SYSTEM
2001 PRIUS (RM778U)
DIAGNOSTIC TROUBLE CODE CHART
DTC No.
(See Page)Detection ItemTrouble Area
11*1
(DI±876)Room temp. sensor circuit

Room temp. sensor

Harness or connector between room temp. sensor and A/C
amplifier

A/C amplifier
12*2
(DI±879)Ambient temp. sensor circuit

Ambient temp. sensor

Harness and connector between ambient temp. sensor and
ECM

ECM

Harness and connector between ECM and A/C amplifier

A/C amplifier
13
(DI±882)Evaporator temp. sensor circuit

Evaporator temp. sensor

Harness and connector between evaporator temp. sensor
and A/C amplifier

A/C amplifier
14
(DI±885)Engine coolant temp. sensor circuit

Water temp. sensor

Harness and connector between engine coolant temp. sensor
and ECM

ECM

Harness and connector between ECM and A/C amplifier
21*3
(DI±888)Solar sensor circuit

Solar sensor

Harness or connector between room temp. sensor and A/C
amplifier

A/C amplifier
22*4
(DI±891)
All conditions below are detected for 3 sec. or more
(g) Engine speed: 500 rpm or more
(h) Ratio between engine and compressor rpm deviates 20 %
or more in comparison to normal operation
Compressor drive belt

Compressor lock sensor

Compressor

Harness and connector between compressor lock sensor and
A/C amplifier
23
(DI±894)
Open in pressure switch circuit
Abnormal refrigerant pressure
[below 196 kPa (2.0 kgf/cm
2, 28 psi) over
3,140 kPa (32.0 kgf/cm2, 455 psi)]

Pressure switch

Harness or connector between pressure switch and A/C am-
plifier

A/C amplifier
31
(DI±897)Air mix damper position sensor circuit

Air mix control servomotor

Harness or connector between air mix control servomotor
and A/C amplifier

A/C amplifier
32
(DI±900)Air inlet damper position sensor circuit

Air inlet control servomotor

Harness or connector between air inlet control servomotor
and A/C amplifier

A/C amplifier
33
(DI±903)Air outlet damper position sensor circuit

Air outlet control servomotor

Harness or connector between air outlet control servomotor
and A/C amplifier

A/C amplifier
41
(DI±906)Air mix control servomotor circuit

Air mix control servomotor

Air mix damper position sensor

Harness or connector between air mix control servomotor
and A/C amplifier

A/C amplifier

± DIAGNOSTICSAIR CONDITIONING SYSTEM
DI±875
2001 PRIUS (RM778U)42
(DI±909)
Air inlet control servomotor circuit

Air inlet control servomotor

Air inlet damper position sensor

Harness or connector between air inlet control servomotor
and A/C amplifier

A/C amplifier
43
(DI±912)Air outlet control servomotor circuit

Air outlet control servomotor

Air outlet damper position sensor

Harness or connector between air outlet control servomotor
and A/C amplifier

A/C amplifier
HINT:

*1: If the room temp. is approx. ±18.6°C (±3.7°F) or lower, trouble code 11 may be output even though
the system is normal.

*2: If the ambient temp. is approx. ±52.9°C (±61.4°F) or lower, a malfunction code may be output even
though the system is normal.

*3: If the check is being performed in a dark place, DTC 21 (solar sensor circuit abnormal) could be
displayed.

*4: To confirm DTC 22, perform the following steps.
(1) With the engine is running, enter the DTC check mode.
(2) Enter actuator check mode and set the operation to step NO. 1.
(3) Check that the DTC 22 is output.

DI7S4±01
I18176
A9 A8 A7 DI±876
± DIAGNOSTICSAIR CONDITIONING SYSTEM
2001 PRIUS (RM778U)
TERMINALS OF ECU
Symbols (Terminals No.)Wiring ColorConditionSTD Voltage (V)
IG eGND
(A7±1 e A7±7)R e W±BIG ON.10 ± 14
BLW e GND
(A7±3 e A7±7)V e W±BIG ON. Blower motor: OperatePulse generation
MP2+ e GND
(A7±4 e A7±7)GR±B e W±BIG ON.Pulse generation
GND e Body ground
(A7±7 e Body ground)W±B e
Body groundAlwaysContinuity
+B e GND
(A7±8 e A7±7)R±G e W±BAlways10 ± 14
IDH e GND
(A8±10 e A7±7)
Y e W±B
IG ON. Head lamp: ON
Rear defogger: ON
Set temp.: MAX. HOT
10 ± 14
Y e W±B
IG ON. Head lamp: OFF
Rear defogger: OFFBelow 1.0
MPX+ e GND
(A7±11 e A7±7)GR e W±BIG ON.Pulse generation
RF e GND
(A8±1 e A7±7)RWWB
Start engine. Water temp.: Below 90°C
Refrigerant pressure: Below 1,520 kPa10 ± 14(A8±1 e A7±7)R±W e W±BStart engine. Water temp.: Approx. 90°C
Refrigerant pressure: Above 1,520 kPaBelow 1.0
CF e GNDVYWBStart engine. A/C compressor: ONBelow 1.0CF e GND
(A8±2 e A7±7)V±Y e W±BStart engine. A/C compressor: OFF10 ± 14
WP e GND
(A8±3 e A7±7)LRWB
Engine speed: Above 500 rpm
Blower motor: OperateBelow 1.0(A8±3 e A7±7)L±R e W±BEngine speed: Above 500 rpm
Blower motor: Not operate10 ± 14
NE e GND
(A8±4 e A7±7)LG e W±BStart enginePulse generation
ACT e GND
(A8±5 e A7±7)P±G e W±BEngine speed: Idle speed10 ± 14
HTR0 e GND
(A8±6 e A7±7)
P±B e W±B
Start engine
Head lamp: OFF
Rear defogger: OFF
Set temp.: MAX. WARM
Blower mode dial: HI
Mode selector: F/D
Water temp.: Below 55 °C
Below 0.7

± DIAGNOSTICSAIR CONDITIONING SYSTEM
DI±877
2001 PRIUS (RM778U) LOCk e SGLOCK
(A8±9 e A7±18)
W±L e BR±WStart engine. A/C compressor ON.Pulse generation
MGC e GNDLG RWBStart engine. A/C compressor: ONBelow 1.0MGC e GND
(A8±11 e A7±7)LG±R e W±BStart engine. A/C compressor: OFF10 ± 14
PSW e GND
(A8±11 e A7±7)L±Y e W±BA/C refrigerant pressure: less than 0.19 Mpa (2.0 kgf/cm2) or
more than 3.14 Mpa (3,140 kgf/cm2)
From 10 ± 14 to
Below 1.0
HTR2 e GND
(A8±13 e A7±7)
P e W±B
Start engine
Head lamp: OFF
Rear defogger: OFF
Set temp.: MAX. WARM
Blower mode dial: HI
Mode selector: F/D
Water temp.: 55 ± 70°C
Below 0.7
SGLOCK e GND
(A8±18 e A7±7)BR±W e W±BAlwaysContinuity
TE e SGTEWWIG ON. Ambient temp. 25°C (77°F)1.35 ± 1.75TE e SGTE
(A9±1 e A9±2)W e WIG ON. Ambient temp. 40°C (104°F)0.85 ± 1.25
SGTE e GND
(A9±2 e A7±7)W e W±BAlwaysContinuity
SGTR e GND
(A9±3 e A7±7)W e W±BAlwaysContinuity
TR e SGTRWWIG ON. Room temp. 25°C (77°F)1.8 ± 2.2TR e SGTR
(A9±4 e A9±3)W e WIG ON. Room temp. 40°C (104°F)1.2 ± 1.6
TS e S5TSWWIG ON. Solar sensor subject to electric light1.0 or moreTS e S5TS
(A9±5 e A9±6)W e WIG ON. Solar sensor cover by a clothBelow 1.0
S5TS e GND
(A9±6 e A7±7)W e W±BIG ON.4.5 ± 5.5
S5TPM e SGTPM
(A9±7 e A9±9)W e WIG ON.4.5 ± 5.5
TPM e SGTPMWWIG ON. Mode selector: FACEBelow 1.0TPM e SGTPM
(A9±8 e A9±9)W e WIG ON. Mode selector: DEF4.5 ± 5.5
SGTPM e GND
(A9±9 e A7±7)W e W±BAlwaysContinuity
AOF e GNDWWBIG ON. Mode selector: FACE10 ± 14AOF e GND
(A9±10 e A7±7)W e W±BIG ON. Mode selector: DEFBelow 1.0
AOD e GNDWWBIG ON. Mode selector: FACEBelow 1.0AOD e GND
(A9±11 e A7±7)W e W±BIG ON. Mode selector: DEF10 ± 14
AMH e GNDWWBIG ON. Set temp.: Max. COOL10 ± 14AMH e GND
(A9±13 e A7±7)W e W±BIG ON. Set temp.: Max. WARMBelow 1.0
AMC e GNDWWIG ON. Set temp.: Max. COOLBelow 1.0AMC e GND
(A9±14 e A7±7)W e WIG ON. Set temp.: Max. WARM10 ± 14
SGTP e GND
(A9±15 e A7±7)W e W±BAlwaysContinuity
TP e SGTPWWIG ON. Set temp.: Max. COOLBelow 1.0TP e SGTP
(A9±16 e A9±15)W e WIG ON. Set temp.: Max. WARM4.5 ± 5.5
S5TP e SGTP
(A9±17 e A9±15)W e WIG ON.4.5 ± 5.5
S5TPI e SGTPI
(A9±18 e A9±20)W e WIG ON.4.5 ± 5.5

DI±880
± DIAGNOSTICSAIR CONDITIONING SYSTEM
2001 PRIUS (RM778U) Engine idle up does not occur, or is continuous
1. Compressor circuit
2. A/C amplifierDI±927
IN±41
Blinking of A/C indicator1. Compressor lock sensor circuit
2. A/C amplifierDI±891
IN±41

I18376
ECM
E9 THW14
E2 18 E2
Engine Coolant Temp. SensorW
B±RE9 2
1 DI±890
± DIAGNOSTICSAIR CONDITIONING SYSTEM
2001 PRIUS (RM778U)
DTC 14 Engine Coolant Temperature Sensor Circuit
CIRCUIT DESCRIPTION
This sensor detects the engine coolant temperature and sends the appropriate signals to the A/C amplifier.
These signals are used for warm up control when the engine is cold.
DTC No.Detection ItemTrouble Area
14Ohtittt iit

Water temperature sensor

Harness or connector between engine coolant temp. sensor
d ECM14Open or short in water temperature sensor circuit.and ECM

Harness or connector between ECM and A/C amplifier

A/C amplifier
WIRING DIAGRAM
DI7S8±01

S05502
± DIAGNOSTICSAIR CONDITIONING SYSTEM
DI±891
2001 PRIUS (RM778U)
INSPECTION PROCEDURE
1 Check engine coolant temp. sensor using hand±held tester.
PREPARATION:
Connect the hand±held tester to the DLC3.
CHECK:
Check the engine coolant temp. sensor using DATA LIST.
OK Check or replace A/C amplifier.
NG
2 Check engine coolant temp. sensor.
PREPARATION:
Remove engine coolant temp. sensor.
CHECK:
Measure resistance between terminals.
OK:
Resistance is within acceptable zone on chart.
Water temperatureResistance
20°C (68°F)2 ± 3 kW
80°C (176°F)0.2 ± 0.4 kW
NG Replace engine coolant temp. sensor.
OK

DI±892
± DIAGNOSTICSAIR CONDITIONING SYSTEM
2001 PRIUS (RM778U)
3 Check for open and short in harness and connector between ECM and engine
coolant temp. sensor (See page IN±41).
NG Repair or replace harness or connector.
OK
Check multiplex communication system (See page DI±750).

I18379
Compressor
Lock SensorA/C Amplifier
4
29
A8LOCK W±L
18
A8SG LOCK IE14
BR±WW±L
W±LIK14
IK15
BR±W BR±W
IE15 DI±896
± DIAGNOSTICSAIR CONDITIONING SYSTEM
2001 PRIUS (RM778U)
DTC 22 Compressor Lock Sensor Circuit
CIRCUIT DESCRIPTION
This sensor sends 1 pulse par engine revolution to the A/C amplifier. If the number ratio of the compressor
speed divided by the engine speed is smaller than a predetermined value, the A/C amplifier turns the com-
pressor off. And, the indicator flashes at about 1 sec. intervals.
DTC No.Detection ItemTrouble Area
All diti b l d t t d f 3
CompressorAll conditions below are detected for 3 secs. or more.
( ) E i d 450

Com ressor

Compressor drive belt
22(a) Engine speed : 450 rpm or more.
(b) Ratio between engine and compressor speed deviates

Com ressor drive belt

Compressor lock sensor22(b) Ratio between engine and compressor speed deviates
20 % or more in comparison to normal operation

Com ressor lock sensor

Harness or connector between compressor and A/C amplifier 20 % or more in comparison to normal operation.Harness or connector between com ressor and A/C am lifier

A/C amplifier
WIRING DIAGRAM
DI7SA±01

I18005
2
4
N02774
0.2 V/Din.0 V
20 msec/Division (Idling)LCK1 LOCK signal waveform
± DIAGNOSTICSAIR CONDITIONING SYSTEM
DI±897
2001 PRIUS (RM778U)
INSPECTION PROCEDURE
1 Check compressor.
PREPARATION:
(a) Check compressor drive belt tension (See page AC±15).
(b) Check if the compressor does not lock during operation with engine started and blower switch and A/C
switch ON.
NG Adjust drive belt tension or repair compressor.
OK
2 Check compressor lock sensor.
PREPARATION:
Disconnect compressor lock sensor connector.
CHECK:
Measure resistance between terminals 2 and 4 of compressor
lock sensor connector.
OK:
Resistance : at 20 °C (68 °F) : 65 ± 125 W
Reference : Inspection using oscilloscope
During cranking or idling, measure voltage between terminals
LOCK and SGLOCK of A/C amplifier.
HINT:
The correct waveform appears as shown in the illustration on
the left.
NG Replace compressor.
OK