TOYOTA PRIUS 2001 Service Repair Manual

I18160
ON
(+) (±)CF
RF
Terminal Condition Voltage
10 ± 14 V
Below 1.0 V
Below 1.0 V
10 ± 14 V Water temp.: Below 90°C (194 °F)
Refrigerant pressure:
Below 1,520 kPa (15.5 kgf/cm
2, 220 psi) RF e Body
ground
CF e Body
ground
Water temp.: Above 90°C (194 °F)
Refrigerant pressure:
Above 1,520 kPa (15.5 kgf/cm
2, 220 psi)
A/C switch: ON
A/C switch: OFF
DI±954
± DIAGNOSTICSAIR CONDITIONING SYSTEM
2001 PRIUS (RM778U)
INSPECTION PROCEDURE
1 Check voltage between terminals RF, CF of A/C amplifier and body ground.
PREPARATION:
Remove the center cluster module control with connectors still
connected.
CHECK:
(a) Start engine.
(b) Turn A/C switch ON.
(c) Measure voltage between terminal RF, CF of A/C amplifi-
er and body ground at each conditions as shown in the
chart.
OK:
OK Go to step 4.
NG
2 Check Fan No. 1, No. 2 and No. 3 relays (See page AC±65).
NG Replace faulty relay
OK

I18394
Engine Room J/B
CDS Fuse
RDI Fuse
± DIAGNOSTICSAIR CONDITIONING SYSTEM
DI±955
2001 PRIUS (RM778U)
3 Check RDI fuse and CDS fuse.
PREPARATION:
Remove RDI fuse and CDS fuse from engine room J/B.
CHECK:
Check continuity of RDI fuse and CDS fuse.
OK:
Continuity exists.
NG Check for short in all the harness and compo-
nents connected to the RDI fuse (See attached
wiring diagram).
OK
Check harness and connector between A/C control amplifier and battery (See page IN±41).
4 Check fan motor operation (See page AC±67).
NG Replace fan motor.
OK
5 Check pressure switch (See page AC±62).
NG Replace pressure switch.
OK

DI±956
± DIAGNOSTICSAIR CONDITIONING SYSTEM
2001 PRIUS (RM778U)
6 Check engine coolant temp. switch (See page AC±84).
NG Replace water temp. switch.
OK
7 Check harness and connector between A/C amplifier and pressure switch, pres-
sure switch and body ground (See page IN±41).
NG Repair and replace harness and connector.
OK
8 Check harness and connector between A/C amplifier and water temp. switch, wa-
ter temp. switch and body ground (See page IN±41).
NG Repair and replace harness and connector.
OK
Check and replace A/C amplifier.

EM167±04
A13922
± ENGINE MECHANICALCO/HC
EM±1
111 7 Author: Date:
2001 PRIUS (RM778U)
CO/HC
INSPECTION
HINT:
This check is used only to determine whether or not the idle
CO/HC complies with regulations.
1. INSTALL CONDITIONS
(a) Air cleaner installed
(b) Air pipes and hoses of air induction system connected
(c) All accessories switched OFF
(d) All vacuum lines properly connected
(e) EFI system wiring connectors fully plugged
(f) Ignition timing check correctly
(g) Transmission in parking range
(h) Tachometer and CO/HC meter calibrated by hand
2. ACTIVATE INSPECTION MODE AND WARM UP EN-
GINE (See page IN±10)
3. RACE ENGINE AT 2,250 RPM FOR APPROX. 180
SECONDS
HINT:
At the accelerator opening angle of 60% or more, the engine
speed is controlled at 2,250 rpm.
4. INSERT CO/HC METER TESTING PROBE AT LEAST
40 cm (1.3 ft) INTO TAILPIPE DURING IDLING
5. IMMEDIATELY CHECK CO/HC CONCENTRATION
AT IDLE AND/OR 2,250 RPM
Complete the measuring with 3 minutes.
HINT:
When doing the 2 mode (idle and 2,250 rpm) test, these mea-
surement order prescribed by the applicable local regulations.
6. STOP ENGINE

EM±2
± ENGINE MECHANICALCO/HC
111 8 Author: Date:
2001 PRIUS (RM778U)
If the CO/HC concentration does not comply with regulations,
troubleshoot in the order given below.

Check heated oxygen sensor operation.
(See page DI±44)

See the table below for possible causes, and then inspect
and correct the applicable causes if necessary.
COHCProblemsCauses
NormalHighRough idle1. Faulty ignitions:

Incorrect timing

Fouled, shorted or improperly gapped plugs

Open or crossed high±tension cords
2. Incorrect valve clearance
3. Leaky intake and exhaust valves
4. Leaky cylinders
LowHighRough idle
(Fluctuating HC reading)1. Vacuum leaks:

PCV hoses

Intake manifold

Throttle body
2. Lean mixture causing misfire
HighHighRough idle
(Black smoke from exhaust)1. Restricted air filter
2. Plugged PCV valve
3. Faulty EFI systems:

Faulty pressure regulator

Defective water temperature sensor

Defective air flow meter

Faulty ECM

Faulty injectors

Faulty throttle position sensor
NormalHigh1. Faulty HCAC:

Faulty VSV

Faulty actuator

EM1IT±02
F12396
TOYOTA Hand±held
Tester
DLC3
A13923
± ENGINE MECHANICALCOMPRESSION
EM±3
111 9 Author: Date:
2001 PRIUS (RM778U)
COMPRESSION
INSPECTION
HINT:
If there is lack of power, excessive oil consumption or poor fuel
economy, measure the compression pressure.
NOTICE:
The measurement of compression pressure should be per-
formed in the Cranking Mode.
1. WARM UP AND STOP ENGINE
Allow the engine to warm up to normal operating temperature.
2. REMOVE AIR CLEANER ASSEMBLY
3. REMOVE IGNITION COIL (See page IG±6)
4. REMOVE SPARK PLUGS
5. CONNECT TOYOTA HAND±HELD TESTER
(a) Connect the TOYOTA hand±held tester to the DLC3.
(b) Select the cranking mode on the TOYOTA hand±held tes-
ter.
(c) Please refer TOYOTA hand±held tester operato's manual
for further details.
6. INSPECT CYLINDER COMPRESSION PRESSURE
(a) Insert a compression gauge into the spark plug hole.
(b) Fully open the throttle.
(c) While cranking the engine, measure the compression
pressure.
HINT:
In the Cranking Mode, the engine speed is automatically con-
trolled at 250 rpm and the throttle valve is also automatically set
in fully±opened condition.
(d) Repeat steps (a) through (c) for each cylinder.
NOTICE:
This measurement must be done in as short a time as pos-
sible.
Compression pressure:
728 kPa (7.4 kgf/cm
2, 106 psi)
Minimum pressure:
534 kPa (5.4 kgf/cm
2, 77 psi)
Difference between each cylinder:
98 kPa (1.0 kgf/cm
2, 14 psi) or less

EM±4
± ENGINE MECHANICALCOMPRESSION
1120 Author: Date:
2001 PRIUS (RM778U)
(e) If the cylinder compression in one more cylinders is low,
pour a small amount of engine oil into the cylinder through
the spark plug hole and repeat steps (a) through (c) for
cylinders with low compression.

If adding oil helps the compression, it is likely that
the piston rings and/or cylinder bore are worn or
damaged.

If pressure stays low, a valve may be sticking or
seating is improper, or there may be leakage past
the gasket.
7. REINSTALL SPARK PLUGS
8. REINSTALL IGNITION COIL (See page IG±7)

EM169±02
A11244
A11245
Timing Marks
A11218
1
3
21
3
2
11
A11219
3
2
3
2
44
44
± ENGINE MECHANICALVALVE CLEARANCE
EM±5
1121 Author: Date:
2001 PRIUS (RM778U)
VALVE CLEARANCE
ADJUSTMENT
HINT:
Inspect and adjust the valve clearance when the engine is cold.
1. REMOVE CYLINDER HEAD COVER
(See page EM±15)
2. SET NO.1 CYLINDER TO TDC/COMPRESSION
(a) Turn the crankshaft pulley, and align its groove with the
timing mark º0º of the timing chain cover.
(b) Check that both timing marks on the camshaft timing
sprocket and valve timing controller assembly are facing
right upas shown in the illustration.
If not, turn the crankshaft 1 revolution (360°) and align the
marks as above.
3. INSPECT VALVE CLEARANCE
(a) Check only the valves indicated.

Using a feeler gauge, measure the clearance be-
tween the valve lifter and camshaft.

Record the out±of±specification valve clearance
measurements. They will be used later to determine
the required replacement adjusting shim.
Valve clearance (Cold):
Intake
0.17 ± 0.23 mm (0.007 ± 0.009 in.)
Exhaust
0.27 ± 0.33 mm (0.011 ± 0.013 in.)
(b) Turn the crankshaft 1 revolution (360°) and align the mark
as above. (See procedure in step 2)
(c) Check only the valves indicated as shown. Measure the
valve clearance. (See procedure in step (a))

A11252Matchmarks
A10471
EM±6
± ENGINE MECHANICALVALVE CLEARANCE
1122 Author: Date:
2001 PRIUS (RM778U)
4. ADJUST VALVE CLEARANCE
(a) Set the No.1 cylinder to the TDC/compression (See pro-
cedure in step 2).
(b) Place matchmarks on the timing chain and camshaft tim-
ing sprockets.
(c) Remove the 2 plug from the timing chain cover.
(d) Using drivers or equipment, while rotating the stopper
plate of the tensioner downward, turn the exhaust cam-
shaft right a little and push in the plunger of the chain ten-
sioner as shown in the illustration.
HINT:
When the stopper plate cannot be lowered easily, rotate the ex-
haust camshaft right and left a little.
(e) Insert a bar of ù 2 ± 3 mm (0.08 ± 0.12 in.) into the holes
in the stopper plate and tensioner to fix the stopper plate.
HINT:

At this time, it is easier to fix by installing the bar while ro-
tate the camshaft right and left a little.

Fix the bar with tape so that the bar does not come off.
(f) Remove the timing chain from the camshaft timing
sprocket.
NOTICE:

Never rotate the crankshaft with the timing chain re-
moved.

When rotating the camshaft with the timing chain re-
moved, rotate the crankshaft counterclockwise 40°
from the TDC and align the oil jet hole with the paint
mark before rotating it.

When installing the timing chain, make sure to return
it to the position of the matchmarks for camshaft and
then rotate the crankshaft clockwise to return.
HINT:
When the chain cannot be removed easily, rotate the intake
camshaft right and left a little.
(g) Hold the hexagonal portion of the camshaft with a
wrench, and remove the bolt and valve timing controller
assembly with the chain.
NOTICE:
Do not disassembled the valve timing controller assembly.
(h) Remove the intake and exhaust camshaft assembly.
HINT:
When disconnect the timing chain from the camshaft timing
sprocket, holding the timing chain.

A11247
Valve Lifter
A01082
± ENGINE MECHANICALVALVE CLEARANCE
EM±7
1123 Author: Date:
2001 PRIUS (RM778U)
(i) Tie the timing chain with a string as shown in the illustra-
tion.
NOTICE:

Be careful not to drop anything inside the timing
chain cover.

Do not allow the chain to come into contact with water
or dust.
(j) Remove the valve lifters.
(k) Determine the replacement valve lifter size according to
these Formula or Charts:

Using a micrometer, measure the thickness of the
removed lifter.

Calculate the thickness of a new lifter so the valve
clearance comes within the specified value.
T.......... Thickness of used lifter
A......... Measured valve clearance
N......... Thickness of new lifter
Intake
N = T + (A ± 0.20 mm (0.008 in.))
Exhaust
N = T + (A ± 0.30 mm (0.012 in.))

Select a new lifter with a thickness as close as pos-
sible to the calculated values.
HINT:
Lifter are available in 35 sizes in increments of 0.020 mm
(0.0008 in.), from 5.060 mm (0.1992 in.) to 5.740 mm (0.2260
in.).