O2 sensor TOYOTA PRIUS 2001 Service Repair Manual

± 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.

± 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

DI7S3±01
± DIAGNOSTICSAIR CONDITIONING SYSTEM
DI±879
2001 PRIUS (RM778U)
PROBLEM SYMPTOMS TABLE
SymptomSuspect AreaSee page
Whole function of the does not operate3. A/C amplifier
4. IG power source circuitIN±41
DI±916
Air Flow Control: No blower operation1. IG power source circuit
2. Heater main relay circuit
3. Blower motor circuit
4. A/C amplifierDI±916
DI±921
DI±924
IN±41
Air Flow Control: No blower control1. Heater main relay circuit
2. Blower motor circuit
3. A/C amplifierDI±921
DI±924
IN±41
Air Flow Control: Insufficient air flow1. Blower motor circuitDI±924
Temperature Control: No cool air comes out1. Refrigerant volume
2. Drive belt tension
3. Refrigeration system inspection with manifold gauge set
4. Compressor circuit
5. Pressure switch circuit
6. Compressor lock sensor circuit
7. Air mix damper position sensor circuit
8. Air mix damper control servomotor circuit
9. Room temperature sensor circuit
10.Ambient temperature sensor circuit
11. A/C amplifierAC±3
AC±15
AC±3
DI±927
DI±894
DI±891
DI±897
DI±906
DI±874
DI±879
IN±41
Temperature Control: No warm air comes out1. Air mix damper position sensor circuit
2. Air mix damper control servomotor circuit
3. DC/DC converter circuit
4. PTC heater circuit
5. Room temperature sensor circuit
6. Ambient temperature sensor circuit
7. Evaporator temperature sensor circuit
8. A/C amplifierDI±897
DI±906
DI±934
DI±937,
DI±942
DI±876
DI±882
DI±885
IN±41
Temperature Control: Output air is warmer or cooler that the set
temperature or response is slow1. Refrigerant volume
2. Drive belt tension
3. Refrigeration system inspection with manifold gauge set
4. Radiator fan and condenser fan circuit
5. Solar sensor circuit
6. Room temperature sensor circuit
7. Ambient temperature sensor circuit
8. Evaporator temperature sensor circuit
9. Air mix damper position sensor circuit
10.Air mix damper control servomotor circuit
11. Evaporator
12.Heater radiator
13.Expansion valve
14.A/C amplifierAC±3
AC±15
AC±3
DI±947
DI±888
DI±876
DI±879
DI±885
DI±897
DI±906
AC±28
AC±28
AC±52
IN±41
Temperature Control: No temperature control (only Max. cool or
Max. warm)1. Room temperature sensor circuit
2. Ambient temperature sensor circuit
3. Air mix damper position sensor circuit
4. Air mix damper control servomotor circuit
5. A/C amplifierDI±876
DI±882
DI±897
DI±906
IN±41
No air inlet control1. Air inlet damper position sensor circuit
2. Air inlet damper control servomotor circuit
3. A/C amplifierDI±900
DI±909
IN±41

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

DI7S5±01
I18376
A/C Amplifier
W
SGTR 3
A9
2
1 A11
A/C Room Temp.
Sensor
W
TR 4
A9
± DIAGNOSTICSAIR CONDITIONING SYSTEM
DI±881
2001 PRIUS (RM778U)
CIRCUIT INSPECTION
DTC 11 Room Temperature Sensor Circuit
CIRCUIT DESCRIPTION
This sensor detects the temperature inside the cabin and sends the appropriate signals to the A/C amplifier.
DTC No.Detection ItemTrouble Area

Room temperature sensor.
11Open or short in room temperature sensor circuit.
Harness or connector between room temp. sensor and A/C
amplifieramplifier.

A/C amplifier.
WIRING DIAGRAM

I18162
ON
SGTR
TR
(±) (+)
I00317
DI±882
± DIAGNOSTICSAIR CONDITIONING SYSTEM
2001 PRIUS (RM778U)
INSPECTION PROCEDURE
1 Check voltage between terminals TR and SGTR of A/C amplifier connector.
PREPARATION:
(a) Remove center cluster module control with connectors
still connected.
(b) Turn the ignition switch ON.
CHECK:
Check voltage between terminals TR and SGTR of A/C amplifi-
er connector at each temperature.
OK:
at 25 °C (77 °F) : 1.8 ± 2.2 V
at 40 °C (104 °F) : 1.2 ± 1.6 V
HINT:
As the temperature increases, the voltage decreases.
NG Go to step 2.
OK
Proceed to next circuit inspection shown on problem symptoms table (See page DI±874). Howev-
er, if DTC 11 is output, check and replace A/C amplifier.
2 Check room temperature sensor.
PREPARATION:
Remove room temperature sensor (See page AC±60).
CHECK:
Check resistance between terminals 1 and 2 of room tempera-
ture sensor connector at each temperature.
OK:
at 25 °C (77 °F) : 1.6 ± 1.8 kW
at 40 °C (104 °F) : 0.5 ± 1.7 kW
HINT:
As the temperature increases, the resistance decreases.
NG Replace room temperature sensor.
OK

I18377
A/C amplifier
A7
Ambient Temp.
SensorMPX+
A71
1 2 15
MP2+ A74 3 2Combination Meter
MPX+
MPX±GR
GR±B B8 MPX+
MPX±16
B8 Body ECU
GR
1MPX TAM
2MPX E2
14
E10
13
E1023
E8
18
E8 ECM
W±GIA25
IK12W±G GR±L11
4 G1 Gateway ECU
GR±B
2MPD
1MPD
C11
C11
BR
BR±W G1 G1 DI±884
± DIAGNOSTICSAIR CONDITIONING SYSTEM
2001 PRIUS (RM778U)
DTC 12 Ambient Temperature Sensor Circuit
CIRCUIT DESCRIPTION
This sensor detects the ambient temperature and sends the appropriate signals to the A/C amplifier.
DTC No.Detection ItemTrouble Area

Ambient temperature sensor

Harness or connector between ambient temperature sensor
12Open or short in ambient temperature sensor circuit

Harness or connector between ambient tem erature sensor
and ECM

ECM
ECM

Harness or connector between ECM and A/C amplifier

A/C amplifier.
WIRING DIAGRAM
DI7S6±01

I05262
1
2
DI±886
± DIAGNOSTICSAIR CONDITIONING SYSTEM
2001 PRIUS (RM778U)
2 Check ambient temperature sensor.
PREPARATION:
Disconnect ambient temperature sensor connector.
CHECK:
Check resistance between terminals 1 and 2 of ambient tem-
perature sensor connector at each temperature.
OK:
Resistance
at 25 °C (77 °F) : 1.6 ± 1.8 kW
at 40 °C (104 °F) : 0.5 ± 0.7 kW
HINT:
As the temperature increases, the resistance decreases.
NG Replace ambient temperature sensor.
OK
Check multiplex communication system (See page DI±750).

I18376
A/C Amplifier
W
SGTE 2
A9
1
2 A13
A/C Thermistor
W
TE 1
A9
± DIAGNOSTICSAIR CONDITIONING SYSTEM
DI±887
2001 PRIUS (RM778U)
DTC 13 Evaporator Temperature Sensor Circuit
CIRCUIT DESCRIPTION
This sensor detects the temperature inside the cooling unit and sends the appropriate signals to the A/C
amplifier.
DTC No.Detection ItemTrouble Area

Evaporator temperature sensor.
13Open or short in evaporator temperature sensor circuit.
Harness or connector between evaporator temperature sen-
sor and A/C amplifiersor and A/C amplifier.

A/C amplifier.
WIRING DIAGRAM
DI7S7±01

I18161
ON
SGTE TE
(±) (+)
AC0175
Thermometer
Ice
ThermistorOhmmeter
More
than
10 cm
(3.94 in.)
DI±888
± DIAGNOSTICSAIR CONDITIONING SYSTEM
2001 PRIUS (RM778U)
1 Check voltage between terminals TE and SGTE of A/C amplifier connector.
PREPARATION:
(a) Remove center cluster module control with connectors
still connected.
(b) Turn ignition switch ON.
CHECK:
Measure voltage between terminals TE and SGTE of A/C am-
plifier connector at each temperature.
OK:
Voltage
at 0 °C (32 °F) : 2.0 ± 2.4 V
at 15 °C (59 °F) : 1.4 ± 1.8 V
HINT:
As the temperature increases, the voltage decreases.
NG Go to step 2.
OK
Proceed to next circuit inspection shown on problem symptoms table (See page DI±874). Howev-
er, if DTC 13 is displayed, check and replace A/C amplifier.
2 Check evaporator temperature sensor.
PREPARATION:
Remove evaporator temperature sensor (See page AC±27).
CHECK:
Check resistance between terminals 1 and 2 of evaporator tem-
perature sensor connector at each temperature.
OK:
Resistance
at 0 °C (32 °F) : 4.6. ± 5.1 kW
at 15 °C (59 °F) : 2.1 ± 2.6 kW
HINT:
As the temperature increases, the voltage decreases.
NG Replace evaporator temperature sensor.
OK