engine TOYOTA PRIUS 2001 Service Repair Manual

Max. COOL e 20.5 (66)
21.0 e 23.5 (67 e72)±10 % (Fully closed)Cool air comes out Temp. Setting °C (°F)Air Mix Damper
Condition
24.0 e 26.0 (73 e77)
26.5 e 29.0 (78 e83)
29.5 (84) eMax. WARM100 % (Fully opened)
""
50 %
"
Warm air comes out
DI±912
± DIAGNOSTICSAIR CONDITIONING SYSTEM
2001 PRIUS (RM778U)
INSPECTION PROCEDURE
1 Actuator check.
PREPARATION:
(a) Warm up the engine.
(b) Set to the actuator check mode (See page DI±866).
CHECK:
Operate the temperatur control switch and check the operation of the air mix damper and the condition of
the blower.
OK:
OK Proceed to next circuit inspection shown on
problem symptoms table (See page DI±874).
NG

I18388
A/C Amplifier
11
A7MPX+ GR
4
MPX+
BJ6
J/C
HTR Relay
J/C
Battery4
A7
MP2+ C11
Combination Meter
MPX±
11 GR±B
MPX1 MPX2
10
B8
14 13
11
B8 MPX+
MPX±
MPD2
MPD1
Instrument Panel J/B
HRLY6
2FL±O
BR R 4
1F
5 3
2
HTR
13
1J
8
1K
3
1B
3
1K
To Blower Motor
W13
IE1
R
A
J23
CJ22
R
FL Block
No. 1 DC/DC
B±G
F11 1
F13 1
1
MAINW±B
A F18
FL Block
No. 2
AWInstrument Panel J/B
1
2H
8
2K
IG1
Relay
3
25
1AM1
W±GI15
Ignition
SW
HTRAM1
3
2B
6
2D
3
2D
IG12
4
B±Y
J11
J/C
ID
IE W±BA
AJ1
J/C
3 2
E10 E10ECM
GR
GR±LC1
Gateway ECU
GR±B
J7 J/C
Engine Room J/B Body ECU DI±926
± DIAGNOSTICSAIR CONDITIONING SYSTEM
2001 PRIUS (RM778U)
Heater Main Relay Circuit
CIRCUIT DESCRIPTION
The heater main relay is switched on by signals from the A/C amplifier. It supplies power to the blower motor.
WIRING DIAGRAM
DI7SK±01

BE1850 BE1844I00312125
3
125
3
4
4
I18394
Engine Room J/B
HTR
Fuse
± DIAGNOSTICSAIR CONDITIONING SYSTEM
DI±927
2001 PRIUS (RM778U)
INSPECTION PROCEDURE
1 Check heater main relay.
PREPARATION:
Remove heater main relay from engine room J/B.
CHECK:
Check continuity between each pair of terminals of heater main
relay shown below.
OK:
Tester connectionSpecified condition
1 ± 4No continuity
2 ± 4Continuity
3 ± 562.5 ± 90.9 W
PREPARATION:
Apply battery positive voltage between terminals 3 and 5.
CHECK:
Check continuity between each pair of terminal shown below.
OK:
Tester connectionSpecified condition
1 ± 2Continuity
2 ± 4No continuity
NG Replace hater main relay.
OK
2 Check HTR fuse
PREPARATION:
Remove HTR fuse from engine room J/B.
CHECK:
Check continuity of HTR fuse.
OK:
Continuity exists.
NG Check for short in all the harness and compo-
nents connected to the HTR fuse (See page
IN±41).
OK

I18387
LG±R
IE18
1
F18
FL Block No. 2
BatteryInstrument Panel J/B
I15
Ignition
SW J6
J/C
AA E1022
1F3
1A5
2D6
2K8
3
2B Engine Room J/B
IG1 Relay ACT
B±Y 35
21
4
IG1
AM1
2 W
A
J11
J/C
ID MAINFL Block No. 1
F111
F131
1DC/DC
B±GW±BA/C Amplifier
A2
A/C Magnetic
Clutch W±G AM12H1 2D3 HTRCLR MG Relay
1F4 12
5
3A85
ACT
A8 10
MGC LG±R
B±L
IE113
R
R
R
J/C
J21A
J20C
R ECM DI±932
± DIAGNOSTICSAIR CONDITIONING SYSTEM
2001 PRIUS (RM778U)
Compressor Circuit
CIRCUIT DESCRIPTION
A/C amplifier switches the A/C magnetic clutch relay ON, thus turning the A/C compressor magnetic clutch
ON.
WIRING DIAGRAM
DI7SM±01

I18169
MGC
(+)
(±) ON
Z18060
15 2
3
12 3 5
± DIAGNOSTICSAIR CONDITIONING SYSTEM
DI±933
2001 PRIUS (RM778U)
INSPECTION PROCEDURE
1 Check voltage between terminal MGC of A/C amplifier and body ground.
CHECK:
(a) Start engine.
(b) Push AUTO SW.
(c) Measure voltage between terminal MGC of A/C amplifier
connector and body ground when A/C switch is On and
OFF.
OK:
A/C switchVoltage
ONBelow 0.7 V
OFF10 ± 14 V
OK Go to step 5.
NG
2 Check magnetic clutch relay.
PREPARATION:
Remove magnetic clutch relay from engine room J/B.
CHECK:
Check continuity between each pair of terminals shown below
of magnetic clutch relay.
OK:
Tester connectionSpecified condition
1 ± 262.5 ± 90.9 W
3 ± 5No continuity
PREPARATION:
Apply battery positive (+) voltage between terminals 1 and 2.
CHECK:
Check continuity between terminals 3 and 5.
OK:
Continuity exists.
NG Replace magnetic clutch relay.
OK

I18006
1
I18156
ACT
DI±934
± DIAGNOSTICSAIR CONDITIONING SYSTEM
2001 PRIUS (RM778U)
3 Check A/C magnetic clutch.
PREPARATION:
Disconnect magnetic clutch connector.
CHECK:
Connect positive (+) lead connected to battery to magnetic
clutch connector terminal 3 and negative (±) lead to body
ground.
OK:
Magnetic clutch is energized.
NG Repair A/C magnetic clutch.
OK
4 Check harness and connector between magnetic clutch relay and A/C amplifier,
A/C compressor and body ground (See page IN±41).
NG Repair or replace harness or connector.
OK
Proceed to next circuit inspection shown on
problem symptons table (See page DI±874).
5 Check voltage between terminal ACT of A/C amplifier connector side and body
ground.
PREPARATION:
(a) Disconnect A/C amplifier connector.
(b) Turn ignition switch ON.
CHECK:
Check voltage between terminal ACT of A/C amplifier harness
side connector.
OK:
Voltage : 10 ± 14 V
NG Check and replace engine ECU.
OK

I18157
ACT(±) (+)
ON
± DIAGNOSTICSAIR CONDITIONING SYSTEM
DI±935
2001 PRIUS (RM778U)
6 Check voltage between terminal ACT of A/C amplifier connector and body
ground.
PREPARATION:
(a) Remove center cluster module control with connector still
connected.
(b) Start the engine and push AUTO switch.
CHECK:
Check the voltage between terminal ACT of A/C amplifier con-
nector and body ground when magnetic clutch is ON and OFF
by A/C switch.
OK:
Magnetic clutchVoltage
ON10 ± 14 V
OFFBelow 1.0 V
NG Check and replace A/C amplifier.
OK
7 Check harness and connector between magnetic clutch relay and A/C amplifier
(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).

I18381
A/C Amplifier
WP
A93
F18
FL Block No. 2
BatteryInstrument Panel J/BC
R R
2D3 J21A
2D6
2K8 2H1
B±Y HTR
IG1 Relay
AM1
J11
J/C 3
5
2
1
W
A
ID MAIN
FL Block No. 1F111
F131
1DC/DC
B±GA/C W/P Relay
L±R
W2
Water Pump
Motor
A
J1
J/C IG14 2 W±GAM1 2B3
I15 Ignition SWJ20
IE1 13 RJ6
J/C
AA
RREngine Room R/B No. 3
3
33
3 351
2
IE120
L±R
L
1
2 J/C
A
AJ7
J/C W±B
IE DI±936
± DIAGNOSTICSAIR CONDITIONING SYSTEM
2001 PRIUS (RM778U)
Water Pump Circuit
CIRCUIT DESCRIPTION
This is hte power source for the water pump motor.
WIRING DIAGRAM
DI7SN±01

I18171
(+) (±)WP ON
Z18060
15 2
3
123 5
± DIAGNOSTICSAIR CONDITIONING SYSTEM
DI±937
2001 PRIUS (RM778U)
INSPECTION PROCEDURE
1 Check voltage between terminal WP of A/C amplifier and body ground.
PREPARATION:
(a) Remove the center cluster module control with connec-
tors still connected.
(b) Start engine.
(c) Operate blower motor.
CHECK:
Measure voltage between terminal WP of A/C amplifier and
body ground when each condition as shown in the chart.
OK:
conditionVoltage
Engine running10 ± 14 V
Engine stopBelow 1.0 V
OK Proceed to next circuit inspection shown on
problem symptoms table (See page DI±874).
NG
2 Check A/C water pump relay.
PREPARATION:
Remove the A/C water pump relay from engine room R/B NO.
3.
CHECK:
Check continuity between each pair of terminals shown below
of magnetic clutch relay.
OK:
Tester connectionSpecified condition
1 ± 262.5 ± 90.9 W
3 ± 5No continuity
PREPARATION:
Apply battery positive (+) voltage between terminals 1 and 2.
CHECK:
Check continuity between terminals 3 and 5.
OK:
Continuity exists.
NG Replace magnetic clutch relay.
OK

I18386
A8 A8 13
6HTR2
HTR0 A/C Amplifier
P P
IE118
IE116 L±R
P±B
P±B
P±B
L±Y
G±R
1
23
41
2 P2
P2P2
P2P1
P1PTC Heater
W±B
W±B W±B
W±B
W±B
J11
J/CJ1
J/C AA
AA
IE ID IA1
IA1 Engine Room R/B No.3
3
3
3
3
3
3 3
3
3
3
3
3
3
3
3
3HTR3 Relay
HTR2 Relay
HTR1 Relay1
2
5
3
1
2
5
3
1
2
5
3
HTR1
HTR2
HTR3 R±L
G
R±L
G±W
R±L
B±R
W
Instrument Panel J/B
2G
2D
2H
2K 2B8
6
1
8 3GAUGE
IG1 Relay
5 3
21
AM1
B±Y
W±G
24
AM1 IG1 I15
Ignition SW
DC/DCF13
F13 F131
1 1FL Block No.1
F18 FL Block No.2
BatteryMAINW±B
W5
1
± DIAGNOSTICSAIR CONDITIONING SYSTEM
DI±943
2001 PRIUS (RM778U)
WIRING DIAGRAM