diagnosis TOYOTA SEQUOIA 2001 Service Repair Manual

IN01T±18
± INTRODUCTIONHOW TO TROUBLESHOOT ECU CONTROLLED
SYSTEMSIN±23
23 Author: Date:
HOW TO TROUBLESHOOT ECU CONTROLLED SYSTEMS
GENERAL INFORMATION
A large number of ECU controlled systems are used in the SEQUOIA. In general, the ECU controlled system
is considered to be a very intricate system requiring a high level of technical knowledge and expert skill to
troubleshoot. However, the fact is that if you proceed to inspect the circuits one by one, troubleshooting of
these systems is not complex. If you have adequate understanding of the system and a basic knowledge
of electricity, accurate diagnosis and necessary repair can be performed to locate and fix the problem. This
manual is designed through emphasis of the above standpoint to help service technicians perform accurate
and effective troubleshooting, and is compiled for the following major ECU controlled systems:
The troubleshooting procedure and how to make use of it are described on the following pages.
SystemPage
1. EngineDI±1
2. Automatic TransmissionDI±515
3. Air Suspension Control SystemDI±695
4. Tire Pressure Warning SystemDI±796
5. ABS with EBD & BA & TRAC & VSC SystemDI±891
6. Can Communication SystemDI±1060
7. Supplemental Restraint SystemDI±1118
8. Power Seat Control System w/ Driving Position MemoryDI±1501
9. Cruise Control SystemDI±1536
10.Engine Immobilizer SystemDI±1570
11. Combination Meter SystemDI±1601
12.Sliding Roof SystemDI±1661
13.Body Control SystemDI±1678
14.Driver Door Control SystemDI±1778
15.Passenger Door Control SystemDI±1814
16.Back Door Control SystemDI±1850
17.Multiplex Communication SystemDI±1887
18.Audio SystemDI±1955
19.Rear Seat Audio SystemDI±2044
20.Rear Seat Entertainment SystemDI±2078
21.Navigation SystemDI±2159
22.Air Conditioning SystemDI±2297
FOR USING OBD II SCAN TOOL OR TOYOTA HAND±HELD TESTER

Before using the scan tool or tester, the scan tool's instruction book or tester's operator manual should
be read thoroughly.

If the scan tool or tester cannot communicate with ECU controlled systems when you have connected
the cable of the scan tool or tester to DLC3, turned the ignition switch ON and operated the scan tool,
there is a problem on the vehicle side or tool side.
(1) If communication is normal when the tool is connected to another vehicle, inspect the diagnosis
data link line (Bus
line) or ECU power circuit of the vehicle.
(2) If communication is still not possible when the tool is connected to another vehicle, the problem
is probably in the tool itself, so perform the Self Test procedures outline in the Tester Operator's
Manual.

V08423 Knock Sensor 1
GRECM
KNK
E1 12
E6
WIRING DIAGRAM
Wiring Diagram
This shows a wiring diagram of the circuit.
Use this diagram together with ELECTRICAL
WIRING DIAGRAM to thoroughly understand the
circuit.
Wire colors are indicated by an alphabetical code.
B = Black, L = Blue, R = Red, BR = Brown,
LG = Light Green, V = Violet, G = Green,
O = Orange, W = White, GR = Gray, P = Pink,
Y = Yellow, SB = Sky Blue
The first letter indicates the basic wire color and
the second letter indicates the color of the stripe.
DTC P0325Knock Sensor 1 Circuit Malfunction
CIRCUIT DESCRIPTION
Knock sensor is fitted to the cylinder block to detect engine knocking. This sensor contains a piezoelectric 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 Condition Trouble Area
P0325No knock sensor 1 signal to ECM with engine speed,
1,200 rpm or more. Open or short in knock sensor1 circuit
 Knock sensor 1 (looseness)
 ECM
If the ECM detects the above diagnosis conditions, it operates the fall safe function in which the corrective retard angle
value is set to the maximum value.
 Diagnostic Trouble Code No. and Detection Item
 Circuit Description
The major role and operation, etc. of the circuit
and its component parts are explained.
 Indicates the diagnostic trouble code, diagnostic
trouble code set parameter and suspect area of
the problem.

± INTRODUCTIONHOW TO TROUBLESHOOT ECU CONTROLLED
SYSTEMSIN±33
33 Author: Date:
2005 SEQUOIA (RM1146U)
6. CIRCUIT INSPECTION
How to read and use each page is shown below.

FI0048
FI0047
FI0046
IN011±61
± INTRODUCTIONHOW TO TROUBLESHOOT ECU CONTROLLED
SYSTEMSIN±35
35 Author: Date:
2005 SEQUOIA (RM1146U)
HOW TO USE THE DIAGNOSTIC
CHART AND INSPECTION
PROCEDURE
1. CONNECTOR CONNECTION AND TERMINAL IN-
SPECTION

For troubleshooting, diagnostic trouble code charts or
problem symptom table are provided for each circuit with
detailed inspection procedures on the following pages.

When all the component parts, wire harnesses and con-
nectors of each circuit except the ECU are found to be
normal in troubleshooting, then it is determined that the
problem is in the ECU. Accordingly, if diagnosis is per-
formed without the problem symptoms occurring, refer to
step 8 to replace the ECU. So always confirm that the
problem symptoms are occurring, or proceed with inspec-
tion while using the symptom simulation method.

The instructions ºCheck wire harness and connectorº and
ºCheck and replace ECUº which appear in the inspection
procedure, are common and applicable to all diagnostic
trouble codes. Follow the procedure outlined below
whenever these instructions appear.
OPEN CIRCUIT:
This could be due to a disconnected wire harness, faulty con-
tact in the connector, and a connector terminal pulled out, etc.
HINT:

It is rarely the case that a wire is broken in the middle of
it. Most cases occur at the connector. In particular, care-
fully check the connectors of sensors and actuators.

Faulty contact could be due to rusting of the connector
terminals, to foreign materials entering terminals or a de-
formation of connector terminals. Simply disconnecting
and reconnecting the connectors once changes the
condition of the connection and may result in a return to
normal operation. Therefore, in troubleshooting, if no ab-
normality is found in the wire harness and connector
check, but the problem disappears after the check, then
the cause is considered to be in the wire harness or con-
nectors.
SHORT CIRCUIT:
This could be due to a contact between wire harness and the
body ground or to a short circuit occurred inside the switch, etc.
HINT:
When there is a short circuit between the wire harness and body
ground, check thoroughly whether the wire harness is caught
in the body or is clamped properly.

PP±4
± PREPARATIONENGINE MECHANICAL
62 Author: Date:
2005 SEQUOIA (RM1146U)
09843±18040Diagnosis Check Wire No.2
09950±50013Puller C Set
(09951±05010)Hanger 150Crankshaft pulley
Crankshaft timing pulley
(09952±05010)Slide ArmCrankshaft pulley
Crankshaft timing pulley
(09953±05010)Center Bolt 100Crankshaft pulley
Crankshaft timing pulley
(09953±05020)Center Bolt 150Crankshaft pulley
Crankshaft timing pulley
(09954±05011)Claw No.1Crankshaft timing pulley
(09954±05021)Claw No.2Crankshaft pulley
09950±60010Replacer Set
(09951±00240)Replacer 24
(09951±00440)Replacer 44
(09952±06010)Adapter
09950±70010Handle Set

± PREPARATIONSUSPENSION AND AXLE
PP±49
107 Author: Date:
2005 SEQUOIA (RM1146U)
(09710±03051)Bushing ReplacerFront axle
Front suspension
09730±00010Tube RemoverElectronic modulated air suspension
Height control valve
09843±18040Diagnosis Check Wire No.2Tire pressure monitor valve
09922±10010Variable Open WrenchFront suspension
09950±00020Bearing RemoverFront drive shaft
Front differential
Front suspension
Rear differential
09950±30012Puller A Set
(09951±03010)Upper PlateFront differential
Rear differential
(09953±03010)Center BoltFront differential
Rear differential
(09954±03010)ArmFront differential
Rear differential
(09955±03030)Lower Plate 130Front differential
Rear differential
(09956±03020)Adapter 18Front differential
(09956±03050)Adapter 24Rear differential
09950±40011Puller B Set

PP3WW±02
PP±56
± PREPARATIONBRAKE
11 4 Author: Date:
2005 SEQUOIA (RM1146U)
BRAKE
SST (Special Service Tools)
09023±00101Union Nut Wrench 10mm
09023±38201Union Nut Wrench 12mm
09751±36011Brake Line Union Nut 10 x 12 mm
Wrench
09843±18040Diagnosis Check Wire No.2

PP0O0±19
± PREPARATIONBODY ELECTRICAL
PP±71
129 Author: Date:
2005 SEQUOIA (RM1146U)
BODY ELECTRICAL
SST (Special Service Tools)
09843±18040Diagnosis Check Wire No.2

DI3H8±10
Vehicle Brought to Workshop
Customer Problem Analysis P. DI±10
Problem Symptom Confirmation
If the engine does not start perform steps 10 and 12 firstConnect the OBD II scan tool or hand±held tester to DLC3.
If the display indicates a communication fault in the tool, inspect DLC3 P.DI±40
Check DTC and Freeze Frame Data
Record or Print DTC and Freeze Frame Data P. DI±43
Clear DTC and Freeze Frame Data P. DI±43
Visual Inspection
Setting the Check Mode Diagnosis P. DI±44
Symptom Simulation P. IN±24
Basic Inspection P. DI±12DTC Chart P. DI±58
Problem Symptoms Table P. DI±33
Circuit Inspection P. DI±73
Adjustment, Repair
DTC Check P. DI±43
Items insideare titles of pages in
in the bottom portion. See the indicated
pages for detailed explanations. this manual, with the page number
Malfunction
occurs.Malfunction does not occur.
Parts Inspection
Check for Intermittent Problems P. DI±11
Identification of Problem
Confirmation Test
End 1
2
3
4
5
6
7
108
9
11
12
13
15 14
16
Normal Malfunction code.
17The hand±held tester can be used at
bold frame.
± DIAGNOSTICSENGINE
DI±9
203 Author: Date:
2005 SEQUOIA (RM1146U)
HOW TO PROCEED WITH TROUBLESHOOTING
Troubleshoot in accordance with the procedure on the following page.

START
Confirm vehicle VIN
Preparation:
1. Connect hand±held tester to DLC3
2. Turn ignition switch to ON
3. Turn tester ON
Hand±held tester operation:
1. Select DIAGNOSIS
2. Select ENHANCED OBD ll
READ:
Menu Screen:
*********************************
[ VIN ]
*********************************
PRESS [EXIT]
ERROR
PRESS [EXIT] DTC P0630 was detected.
P0630 [VIN Not Programmed
or Mismatch ± ECM/PCM]
Please input the VIN.
PRESS [EXIT] Possible cause:
To Menu Screen
17±digit VIN
displayed 3. Select VIN
DTC P0630 Set VIN Previously StoredVIN Not Stored
[EXIT] [EXIT][EXIT] 2. VIN WRITEVIN
Select VIN READ
1. VIN READ 1. VIN READ
ERROR
ECM does not respond the VIN.
1: VIN is not written yet.
2: Vehicle does not support this
function.
± DIAGNOSTICSENGINE
DI±15
209 Author: Date:
2005 SEQUOIA (RM1146U)
3. READ VIN (Vehicle Identification Number)
(a) Read VIN using a hand±held tester.

START
Confirm vehicle VIN
Preparation:
1. Connect hand±held tester to DLC3
2. Turn ignition switch to ON
3. Turn tester ON
Hand±held tester operation:
Write:
Menu Screen:
This function overwrites the
following VIN with a new VIN.
*********************************
[ VIN ]
*********************************
[YES] to Continue
[NO] to EXIT
To Menu ScreenContinued on next page
NOTICE
Do you wish to continue?
[YES]
[NO] 1. Select DIAGNOSIS
2. Select ENHANCED OBD ll
3. Select VIN
1. VIN READ 1. VIN READVIN
Select VIN WRITE
[YES] or [NO]
[YES] 2. VIN WRITE
To Menu
Screen
[NO]
CONFIRMATION
This function will erase the
DTCs automatically after
writing the VIN.
Do you wish to continue?
[YES]
17±digit VIN displayed VIN Previously Stored
DI±16
± DIAGNOSTICSENGINE
210 Author: Date:
2005 SEQUOIA (RM1146U)
4. WRITE VIN
(a) Write VIN using the hand±held tester.