2001 TOYOTA PRIUS clutch

A03403A03404A03675
M+ Signal Waveform
5 V/
Division
GND
1 msec./Division
M± Signal Waveform
GND
5 V/
Division
1 msec./Division
± DIAGNOSTICSENGINE
DI±109
2001 PRIUS (RM778U)
1 Check throttle control motor circuit.
PREPARATION:
(a) Connect the oscilloscope between terminals M+ or M±
and E1 of the ECM connectors.
(b) Start the engine.
CHECK:
Check the waveform between terminals M+ or M± and E1 of the
ECM connectors when the engine is idling.
OK:
The correct waveforms are as shown.
HINT:
The waveform frequency varies depending on the throttle
opening.
OK Check and replace ECM (See page IN±41).
NG
2 Check throttle control motor (See page SF±24).
NG Replace throttle control motor with magnetic
clutch (See page SF±29).
OK
3 Check for open and short in harness and connector between throttle control mo-
tor and ECM (See page IN±41).
NG Repair or replace harness or connector.
OK
Check and replace ECM (See page IN±41).

FI7012A11860
P±G A/C Control Assembly
A8 E10522
ACTECM
± DIAGNOSTICSENGINE
DI±171
2001 PRIUS (RM778U)
A/C Cut Control Circuit
CIRCUIT DESCRIPTION
This circuit cuts air conditioning operation during vehicle acceleration in order to increase acceleration per-
formance. During acceleration with the vehicle speed at (AT: 25 km/h (16 mph), MT: 40 km/h (25 mph)) or
less, engine speed at (AT: 1,200 rpm, MT:1,600 rpm) or less and throttle valve opening angle at 60° or more,
the A/C magnet switch is turned OFF for several seconds.
WIRING DIAGRAM
INSPECTION PROCEDURE
TOYOTA hand±held tester:
1 Connect the TOYOTA hand±held tester and check operation of air conditioning
cut control.
PREPARATION:
(a) Connect the TOYOTA hand±held tester to the DLC3.
(b) Turn the ignition switch ON and TOYOTA hand±held tester main switch ON.
(c) Start the engine and air conditioning switch ON.
HINT:
A/C magnet clutch is turned ON.
(d) Select the ACTIVE TEST mode on the TOYOTA hand±held tester.
CHECK:
Check operation of A/C magnet clutch cut when air conditioning cut control is operated by the TOYOTA
hand±held tester.
OK:
A/C magnet clutch is turned OFF.
DI7T8±01

I08340
J1
J/CL±Y
A3
A/C Dual Pressure
SwitchA/C amplifier
W±B
IE1
A811
PSW
4
ED 115
A W±B
± DIAGNOSTICSAIR CONDITIONING SYSTEM
DI±899
2001 PRIUS (RM778U)
DTC 23 Pressure Switch Circuit
CIRCUIT DESCRIPTION
This pressure switch sends the appropriate signals to the A/C amplifier when the A/C refrigerant pressure
drops too low or rises too high. When the A/C amplifier receives these signals, if outputs signals via the A/C
amplifier to switch off the compressor relay and turns the magnetic clutch off.
DTC No.Detection ItemTrouble Area

Open inpressure sensor circuit
Pressure switch
23

Open in pressure sensor circuit.

Abnormal refri
gerant pressure.
Pressure switch

Harness or connector between pressure switch and A/C am-
lifi23
Abnormal refrigerant ressure.
below 196 kPa (2.0 kgf/cm2. 28 psi)2
plifier


Refrigerantpipe lineover 3,140 kPa (32.0 kgf/cm2. 455 psi)
Refrigerant pipe line

A/C amplifier
WIRING DIAGRAM

DI7SB±01

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).

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