PCV TOYOTA SEQUOIA 2001 Service User Guide

A20646
20 V
/Division Injector Signal Waveform
20 V
/Division
GND
100 msec./Division (Idling)(Magnification)
GND
1 msec./Division (Idling)
Injection duration
± DIAGNOSTICSENGINE
DI±185
379 Author: Date:
2005 SEQUOIA (RM1146U)DTC No.
DTC Detecting ConditionTrouble Area
P0300Misfiring of random cylinders is detected

Open or short in engine wire

Connector connection

Vacuum hose connection
P0301
P0302
P0303
P0304
P0305
P0306
P0307
P0308
Misfiring of each cylinder is detected

Vacuum hose connection

Ignition system

Injector

Fuel pressure

Mass air flow meter

Engine coolant temperature sensor

Compression pressure

Valve clearance

Valve timing

PCV piping

ECM
HINT:
When several codes for a misfiring cylinder are recorded repeatedly but no random misfire code is recorded,
it indicates that the misfires have been detected and recorded at different times.
Reference: Inspection using the oscilloscope.
With the engine idling, check the waveform between terminals #1 to #8 and E01 of the ECM connectors.
HINT:
The correct waveform is as shown in the illustration.

± DIAGNOSTICSENGINE
DI±193
387 Author: Date:
2005 SEQUOIA (RM1146U)
3 Check connection of PCV piping.
OK:
PCV hose is connected correctly and is not damaged.
NG Repair or replace PCV piping.
OK
4 Connect hand±held tester, and read the number of misfire.
PREPARATION:
(a) Connect the hand±held tester to the DLC3.
(b) Turn the ignition switch ON and push the hand±held tester main switch ON.
(c) Start the engine.
(d) When using hand±held tester, enter the following menu: DIAGNOSIS / ENHANCED OBD II / DATA
LIST / ALL / CYL#1 to CYL#8.
CHECK:
Read the number of misfire on the hand±held tester.
HINT:
When a misfire is not reproduced, be sure to branch below based on the stored DTC.
RESULT:
High Misfire Rate CylinderProceed to
1 or 2 cylindersA
More than 3 cylindersB
B Go to step 15.
A

A20823
Idle engine
RPM
Small Target RPM
Actual idle RPMLarge
Learned value
of the idle speed
controlMaximum
Minimum
Time 0
Time DI±288
± DIAGNOSTICSENGINE
482 Author: Date:
2005 SEQUOIA (RM1146U)
DTC P0505 Idle Air Control System
CIRCUIT DESCRIPTION
The idle speed is controlled by the ETCS (Electronic Throttle Control System).
The ETCS is composed of the throttle motor which operates the throttle valve, and the throttle position sen-
sor, which detects the opening angle of the throttle valve.
The ECM controls the throttle motor to provide the proper throttle valve opening angle to obtain the target
idle speed.
DTC No.DTC Detection ConditionTrouble Area
P0501Idle speed continues to vary greatly from target speed
(2 trip detection logic)

ETCS

Air induction system

PCV hose connection

ECM
MONITOR DESCRIPTION
The ECM regulates the idle speed by opening and closing the throttle valve using the ETCS. The ECM con-
cludes that the idle speed control ECM function is malfunctioning if: 1) the actual idle RPM varies more than
the specified amount, or 2) a learning value of the idle speed control remains at the maximum or minimum
five times or more during a driving cycle. The ECM will turn on the MIL and set a DTC.
Example:
If the actual idle RPM varies from the target idle RPM by more than 100 (*1) rpm five times during a driving
cycle, the ECM will turn on the MIL and a DTC is set.
HINT:
*1: RPM threshold varies with engine load.
DICF6±02

DI±290
± DIAGNOSTICSENGINE
484 Author: Date:
2005 SEQUOIA (RM1146U)
INSPECTION PROCEDURE
HINT:

When the throttle position is slightly opened (the accelerator pedal is slightly depressed) because a
floor carpet is overlapped on the accelerator pedal, or if the accelerator pedal is not fully released, etc.,
DTC P0505 will possibly be detected.

Read freeze frame data using the hand-held tester. Freeze frame data records the engine conditions
when a malfunction is detected. When troubleshooting, freeze frame data can help determine if the
vehicle was running or stopped, if the engine was warmed up or not, if the air±fuel ratio was lean or
rich, as well as other data from the time when a malfunction occurred.
1 Are there any other codes (besides P0505) being output?
PREPARATION:
(a) Connect the hand±held tester to the DLC3.
(b) Turn the ignition switch ON and push the hand±held tester main switch ON.
(c) When using hand±held tester, enter the following menu: DIAGNOSIS / ENHANCED OBD II / DTC
INFO / CURRENT CODES.
CHECK:
Read the DTC using the hand±held tester.
RESULT:
Display (DTC Output)Proceed to
P0505A
ºP0505º and other DTCsB
HINT:
If any other codes besides P0505 are output, perform the troubleshooting for those DTCs first.
B Go to relevant DTC chart (See page DI±58).
A
2 Check connection of PCV piping.
NG Repair or replace PCV piping.
OK

EM±2
± ENGINE MECHANICALCO/HC
2581 Author: Date:
2005 SEQUOIA (RM1146U)
5. IMMEDIATELY CHECK CO/HC CONCENTRATION AT
IDLE AND/OR 2,500 RPM
HINT:
When performing the 2 mode (2,500 rpm and idle) test, follow
the measurement orders are prescribed by the applicable local
regulations.
If the CO/HC concentration does not comply with regulations,
perform troubleshooting in the order given below.
(a) Check the air±fuel ratio sensors and heated oxygen sen-
sors operation.(See page DI±88 and DI±93)
(b) See the table below for possible causes, and then inspect
and correct the applicable causes if necessary.
COHCProblemsCauses
NormalHighRough idle7. Faulty ignitions:

Incorrect timing

Fouled, shorted or improperly gapped plugs
8. Incorrect valve clearance
9. Leaky intake and exhaust valves
10.Leaky cylinders
LowHighRough idle
(fluctuating HC reading)1. Vacuum leaks:

PCV hoses

Intake manifold

Throttle body

Brake booster line
2. Lean mixture causing misfire
HighHighRough idle
(Black smoke from exhaust)1. Restricted air filter
2. Faulty SFI systems:

Faulty pressure regulator

Defective ECT sensor

Faulty ECM

Faulty injectors

Faulty throttle position sensor

Faulty MAF meter

EM0KS±09
A23300
A23301
EM±4
± ENGINE MECHANICALVALVE CLEARANCE
2583 Author: Date:
2005 SEQUOIA (RM1146U)
VALVE CLEARANCE
INSPECTION
HINT:
Inspect and adjust the valve clearance when the engine is cold.
1. REMOVE BATTERY CLAMP COVER
2. REMOVE THROTTLE BODY COVER
3. REMOVE AIR CLEANER AND INTAKE AIR CONNEC-
TOR ASSEMBLY
4. REMOVE NO.3 TIMING BELT COVERS
(See page EM±16)
5. REMOVE IGNITION COILS (See page IG±5)
6. REMOVE RH CYLINDER HEAD COVER
Remove the 9 bolts, seal washers and cylinder head cover.
7. REMOVE LH CYLINDER HEAD COVER
(a) Remove the oil dipstick for the transmission.
(b) Disconnect the PCV hose.
(c) Disconnect the engine wire clamp from the wire bracket
on the cylinder head cover.
(d) Remove the 9 bolts, 9 seal washers and cylinder head
cover.
8. SET NO.1 CYLINDER TO TDC/COMPRESSION
(a) Turn the crankshaft pulley, and align its groove with timing
mark º0º of the No.1 timing belt cover.
(b) Check that the timing marks of the camshaft timing pul-
leys and timing belt rear plates are aligned.
If not, turn the crankshaft 1 revolution (360°) and align the mark
as above.

EM0KV±13
A19404
PS Air Hose
Intake Air ConnectorRadiator Assembly
N´m (kgf´cm, ft´lbf) : Specified torqueDrive BeltA/C Compressor
Connector
A/T Oil Cooler Hose
Fan and Fluid Coupling
Assembly
Fan Pulley
49 (500, 36)
x 4
29 (296, 21)
Throttle Body Cover
MAF Meter Wire
Engine Under Cover (4WD)2WDEngine Under Cover
PS PumpNo. 2 Fan Shroud
Vacuum Hose
PCV Hose
Clip
17 (175, 13)
12 (122, 9)
A/C Compressor
A/C Suction Hose
17 (175, 13)
x 5
29 (296, 21)
29 (296, 21)
± ENGINE MECHANICALTIMING BELT
EM±13
2592 Author: Date:
2005 SEQUOIA (RM1146U)
TIMING BELT
COMPONENTS

EM1WZ±01
A21015
MAF Meter Wire
P/S Air
Hose
No.2 Fan Shroud
Radiator
Assembly
Fan Pulley
Drive BeltA/C Compressor
Connector
Engine Under Cover (2WD)A/C Compressor Fan And Fluid Coupling
AssemblyThrottle Body Cover
Engine Under Cover
49 (500, 36)
x 4
N´m (kgf´cm, ft´lbf) : Specified torque
A/T Oil Cooler Hose
4WD:
Vacuum Hose
PCV Hose
Clip
12 (122, 9)
29 (296, 21)
Suction Hose
Intake Air Connector
x 5
29 (296, 21)
29 (296, 21)
± ENGINE MECHANICALCYLINDER HEAD
EM±29
2608 Author: Date:
2005 SEQUOIA (RM1146U)
CYLINDER HEAD
COMPONENTS

A23321
Fuel Pressure
Pulsation Damper
* 33 (340, 24)

39 (400, 29)
PCV
18 (184, 13)
LH Delivery Pipe
N´m (kgf´cm, ft´lbf) : Specified torque

Non±reusable part
* For use with SST
Grommet
Injector
O±Ring

InsulatorFuel Return Pipe
Front Fuel Pipe
Gasket

Gasket
Throttle Body Assembly
39 (400, 29)
Fuel Pressure RegulatorVacuum Hose
RH Delivery PipeVSV for EVAP
VSV for Secondary Air Injection System
VSV Wire Connector
for ACIS
VSV for ACIS
7.5 (76, 66 in.´lbf)
Union
39 (400, 29)
Union

Upper Gasket
7.5 (76, 66 in.´lbf)
7.5 (76, 66 in.´lbf)
21 (214, 15)
21 (214, 15)
Ventilation
Hose
7.5 (76, 66 in.´lbf)
7.5 (76, 66 in.´lbf)

O±Ring

Lower Gasket
7.5 (76, 66 in.´lbf)
18 (185, 13)
± ENGINE MECHANICALCYLINDER HEAD
EM±33
2612 Author: Date:
2005 SEQUOIA (RM1146U)

A23324
(a)
(b)
(c)
(d)
A23325Water Bypass Hose
A23326
A23327
± ENGINE MECHANICALCYLINDER HEAD
EM±37
2616 Author: Date:
2005 SEQUOIA (RM1146U)
13. DISCONNECT HOSES FROM INTAKE MANIFOLD
(a) Disconnect the vacuum hose from the fuel pressure regu-
lator.
(b) Disconnect the PCV hose from the PCV valve on the LH
cylinder head.
(c) Disconnect the EVAP hose (from charcoal canister) from
the VSV for the EVAP.
(d) Disconnect the 2 vacuum hoses from the VSV for the air
injection system.
14. REMOVE INTAKE MANIFOLD ASSEMBLY
(a) Disconnect the 2 water bypass hoses from the throttle
body.
(b) Disconnect the 2 wire clamps from the wire clamp bracket
on the RH delivery pipe.
(c) Remove the 2 bolts holding the engine wire protector from
the intake manifold and cylinder head.
(d) Remove the 2 bolts and ground cables from the RH and
LH cylinder heads.
(e) Remove the bolt and throttle body cover bracket from the
intake manifold.