2001 TOYOTA PRIUS Service Repair Manual

DI±878
± DIAGNOSTICSAIR CONDITIONING SYSTEM
2001 PRIUS (RM778U) TPI e SGTPI
WWIG ON. Air intake selector: FRESHBelow 1.0TPI e SGTPI
(A9±19 e A9±20)W e WIG ON. Air intake selector: RECIRCULATE4.5 ± 5.5
SGTPI e GND
(A9±20 e A7±7)W e W±BAlwaysContinuity
AIR e GNDWWBIG ON. Air intake selector: FRESHBelow 1.0AIR e GND
(A9±21 e A7±7)W e W±BIG ON. Air intake selector: RECIRCULATE10 ± 14
AIF e GNDWWBIG ON. Air intake selector: FRESH10 ± 14AIF e GND
(A9±22 e A7±7)W e W±BIG ON. Air intake selector: RECIRCULATEBelow 1.0

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