2001 TOYOTA PRIUS Service Repair Manual

I18163
ON
(±)TS
S5TS
(+)
DI±894
± DIAGNOSTICSAIR CONDITIONING SYSTEM
2001 PRIUS (RM778U)
INSPECTION PROCEDURE
1 Check voltage between terminals S5TS and TS 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 S5TS and TS of A/C ampli-
fier connector when the solar sensor is subjected to an electric
light, and when the sensor is covered by a cloth.
OK:
ConditionVoltage
Sensor subjected to electric lightBelow 4.0 V
Sensor covered by a cloth4.0 ± 4.5 V
HINT:
As the inspection light is gradually moved away from the sen-
sor, the voltage increases.
NG Go to step 2.
NG
Proceed to next circuit inspection shown on problem symptoms table (See page DI±874). Howev-
er, if DTC 21 is displayed, check and replace A/C amplifier.

I00325
± DIAGNOSTICSAIR CONDITIONING SYSTEM
DI±895
2001 PRIUS (RM778U)
2 Check solar sensor.
PREPARATION:
Remove solar sensor (See page AC±59).
CHECK:
(a) Cover the sensor by a cloth.
(b) Measure resistance between terminals 1 and 2 of solar
sensor connector.
HINT:
Connect positive (+) lead of ohmmeter to terminal 2 and nega-
tive (±) lead to terminal 1 of the solar sensor.
OK:
Resistance : 8W (No continuity)
PREPARATION:
Remove the cloth from the solar sensor and subject the sensor
to electric light.
CHECK:
Measure resistance.
OK:
Resistance : Below 10 kW (Continuity)
HINT:
As the electric light is moved gradually away from the sensor,
the resistance increases.
NG Replace solar sensor.
OK
3 Check harness and connector between A/C amplifier and solar sensor
(See page IN±41).
NG Repair or replace harness or connector.
OK
Check and replace A/C amplifier.

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

DI±898
± DIAGNOSTICSAIR CONDITIONING SYSTEM
2001 PRIUS (RM778U)
3 Check harness and connector between A/C amplifier and compressor lock sen-
sor (See page IN±41).
NG Repair or replace harness or connector.
OK
Proceed to next circuit inspection shown on problem symptoms table (See page DI±874). Howev-
er, if DTC 22 is displayed, check and replace A/C amplifier.