2001 TOYOTA PRIUS Service Repair Manual

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

± DIAGNOSTICSAIR CONDITIONING SYSTEM
DI±889
2001 PRIUS (RM778U)
3 Check harness and connector between A/C amplifier and evaporator tempera-
ture sensor (See page IN±41).
NG Repair or replace harness or connector.
OK
Check and replace A/C amplifier.

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