TOYOTA PRIUS 2001 Service Repair Manual

A13627
ON
#10
(+) (±) #20 #30 #40
FI6588
FI6538
A00064
Injector Signal Waveform
10V/
Division
GND
100 m sec./Division (Idling)GND
Injection duration1 m sec./Division (Idling) 10V/
Division(Magnification)
DI±68
± DIAGNOSTICSENGINE
2001 PRIUS (RM778U)
(b) Disconnect the injector connector.
(c) Ground spark plug.
CHECK:
Check if spark occurs while engine is being cracked.
NOTICE:
To prevent excess fuel being injected from the injectors
during this test, don't crank the engine for more than 5 ± 10
seconds at a time.
OK:
Spark jumps across electrode gap.
NG Replace or check ignition system
(See page IG±1).
OK
3 Check voltage of ECM terminal for injector of failed cylinder.
PREPARATION:
(a) Remove the ECM with connector still connected (See
page SF±62).
(b) Turn the ignition switch ON.
CHECK:
Measure voltage between applicable terminal of the ECM con-
nector and body ground.
OK:
Voltage: 9 ± 14 V
Reference: INSPECTION USING OSCILLOSCOPE
INJECTOR SIGNAL WAVEFORM
With the engine idling, measure between terminals #10 ~ #40 and E01 of the ECM connector.
HINT:
The correct waveforms are shown.

± DIAGNOSTICSENGINE
DI±69
2001 PRIUS (RM778U)
OK Go to step 5.
NG
4 Check resistance of injector of misfiring cylinder (See page SF±9).
NG Replace injector.
OK
Check for open and short in harness and
connector between injector and ECM
(See page IN±41).
5 Check fuel pressure (See page SF±6).
NG Check and repair fuel pump and fuel pipe line
(See page SF±1).
OK
6 Check injector injection (See page SF±12).
NG Replace injector.
OK
7 Check mass air flow merer and engine coolant temp. sensor
(See page SF±22 and SF±49).
NG Repair or replace.

DI±70
± DIAGNOSTICSENGINE
2001 PRIUS (RM778U)
OK
Check compression pressure, valve
clearance and valve timing
(See page EM±3, EM±5, EM±21).

A14027
Knock
SensorECM
KNK1 E7 1
EA1128
B
BR
EB
BR(Shielded)
A
J8 A
J9J/C
± DIAGNOSTICSENGINE
DI±71
2001 PRIUS (RM778U)
DTC P0325 Knock Sensor 1 Circuit Malfunction
CIRCUIT DESCRIPTION
The knock sensor is fitted to the cylinder block to detect engine knocking. This sensor contains a piezoelec-
tric element which generates a voltage when it becomes deformed, which occurs when the cylinder block
vibrates due to knocking. If engine knocking occurs, ignition timing is retarded to suppress it.
DTC No.DTC Detecting ConditionTrouble Area
P0325No knock sensor 1 signal to ECM with engine speed, 2,000
rpm or more
Open or short in knock sensor 1 circuit

Knock sensor 1 (looseness)

ECM
HINT:
If the ECM detects above diagnosis conditions, it operates the fail safe function in which the corrective retard
angle value is set to the maximum value.
WIRING DIAGRAM
DI6V9±02

A13628
E7 Connector LOCK
KNK1
DI±72
± DIAGNOSTICSENGINE
2001 PRIUS (RM778U)
INSPECTION PROCEDURE
HINT:
Read freeze frame data using TOYOTA hand±held tester or OBD II scan tool. Because freeze frame records
the engine conditions when the malfunction is detected, when troubleshooting it is useful for determining
whether the vehicle was running or stopped, the engine warmed up or not, the air±fuel ratio lean or rich, etc.
at the time of the malfunction.
1 Check continuity between terminal KNK1 of ECM connector and body ground.
PREPARATION:
(a) Remove the ECM with connector still connected (See
page SF±62).
(b) Disconnect the E7 connector of the ECM.
CHECK:
Measure resistance between terminal KNK1 of the ECM con-
nector and body ground.
OK:
Resistance: 1 MW or higher
OK Go to step 3.
NG
2 Check knock sensor (See page SF±56).
NG Replace knock sensor.
OK
3 Check for open and short in harness and connector between ECM and knock
sensor (See page IN±41).
NG Repair or replace harness or connector.
OK

A00406
KNK signal waveform
0.5V/
Division
0V
0V5 m sec./Division
100
sec./Division 0.5V/
Division
± DIAGNOSTICSENGINE
DI±73
2001 PRIUS (RM778U)
4 Does malfunction disappear when a good knock sensor is installed?
YES Replace knock sensor.
NO
Check and replace ECM (See page IN±41).
Reference: INSPECTION USING OSCILLOSCOPE

With the engine racing (4,000 rpm) measure between ter-
minal KNK of the ECM connector and body ground.
HINT:
The correct waveforms are as shown.

Spread the time on the horizontal axis, and confirm that
period of the wave is 132 m sec.
(Normal mode vibration frequency of knock sensor:
8.1 kHz)
HINT:
If normal mode vibration frequency is not 8.1 kHz the sensor is
malfunctioning.

A14028
1
2R
E7
J/C
J8NE+ NE± C1
Camshaft
Position
Sensor
2
1 C6
Crankshaft
Position
Sensor
E8 E8
BRG
EBECM
BRBRG2
J8
J9 R G
A A
A24
16 10 (Shielded)
(Shielded)
BRG
DI±74
± DIAGNOSTICSENGINE
2001 PRIUS (RM778U)
DTC P0335 Crankshaft Position Sensor ºAº Circuit
Malfunction
CIRCUIT DESCRIPTION
Crankshaft position sensor (NE signal) consist of a signal plate and pick up coil.
The NE signal plate has 34 teeth and is mounted on the crankshaft. The NE signal sensor generates 34
signals of every engine revolution. The ECM detects the standard crankshaft angle based on the G2 signals,
and the actual crankshaft angle the engine speed by the NE signals.
DTC No.DTC Detecting ConditionTrouble Area
No crankshaft position sensor signal to ECM during cranking.
(2 trip detection logic)
Open or short in crankshaft position sensor circuit.

Crankshaft position sensor
P0335No crankshaft position sensor signal to ECM with engine
speed 600 rpm or more
(2 trip detection logic)

Crankshaft osition sensor

Signal plate (Timing belt guide)

Crankshaft timing pulley

ECM
WIRING DIAGRAM
DI6VA±02

A14463
G2, NE signal waveforms
5V/
Division G2
NE
20 m sec./Division (Idling)
± DIAGNOSTICSENGINE
DI±75
2001 PRIUS (RM778U)
INSPECTION PROCEDURE
HINT:

Perform troubleshooting of DTC 335 1st. If notrouble is found, troubleshoot the following mechanical
system.

Read freeze frame data using TOYOTA hand±held tester or OBD II scan tool. Because freeze frame
records the engine conditions when the malfunction is detected, when troubleshooting it is useful for
determining whether the vehicle was running or stopped, the engine warmed up or not, the air±fuel
ratio lean or rich, etc. at the time of the malfunction.
1 Check resistance of crankshaft position sensor (See page IG±1).
Reference: INSPECTION USING OSCILLOSCOPE
During cranking or idling, check between terminals G2 and
NE±, NE and NE± of the ECM
HINT:
The correct waveforms are as shown.
NG Replace crankshaft position sensor.
OK
2 Check for open and short in harness and connector between ECM and
crankshaft position sensor (See page IN±41).
NG Repair or replace harness or connector.
OK
3 Inspect crankshaft position sensor installation and teeth of crankshaft timing
pulley (See page IG±11 and EM±13).
NG Tighten the sensor.
Replace crankshaft timing pulley.
OK
Check and replace ECM (See page IN±41).

DI±76
± DIAGNOSTICSENGINE
2001 PRIUS (RM778U)
DTC P0340 Camshaft Position Sensor Circuit
Malfunction
CIRCUIT DESCRIPTION
Camshaft position sensor (G22 signal) consist of signal plate and pick up coil.
The G22 signal plate has one tooth on its outer circumference and is mounted on the exhaust camshaft.
When the camshafts rotate, the protrusion on the signal plate and the air gap on the pick up coil change,
causing fluctuations in the magnetic field and generating an electromotive force in the pick up coil.
The NE signal plate has 34 teeth and is mounted on the crankshaft. The NE signal sensor generates 34
signals for every engine revolution. The ECM detects the standard crankshaft angle based on the G22 sig-
nals and the actual crankshaft angle and the engine speed by the NE signals.
DTC No.DTC Detecting ConditionTrouble Area
P0340
No camshaft position sensor signal to ECM during cranking.
(2 trip detection logic)
Open or short in camshaft position sensor circuit

Camshaft position sensor
P0340No camshaft position sensor signal to ECM with engine speed
600 rpm or more

Camshaft osition sensor

Camshaft timing pulley

ECM
WIRING DIAGRAM
Refer to DTC P0335 on page DI±74.
INSPECTION PROCEDURE
HINT:
Read freeze frame data using TOYOTA hand±held tester or OBD II scan tool. Because freeze frame records
the engine conditions when the malfunction is detected, when troubleshooting it is useful for determining
whether the vehicle was running or stopped, the engine warmed up or not, the air±fuel ratio lean or rich, etc.
at the time of the malfunction.
1 Check resistance of camshaft position sensor (Signal generator)
(See page IG±1).
Reference: INSPECTION USING OSCILLOSCOPE
Refer to DTC P0335 on page DI±74 for the INSPECTION USING OSCILLOSCOPE.
NG Replace camshaft position sensor.
OK
DI6VB±02

± DIAGNOSTICSENGINE
DI±77
2001 PRIUS (RM778U)
2 Check for open and short in harness and connector between ECM and camshaft
position sensor (See page IN±41).
NG Repair or replace harness or connector.
OK
3 Inspect sensor installation and tooth of camshaft timing pulley
(See page EM±15).
NG Tighten the sensor.
Replace camshaft timing pulley.
OK
Check and replace ECM (See page IN±41).