2001 TOYOTA SEQUOIA immobilizer

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.

IN±26± INTRODUCTIONHOW TO TROUBLESHOOT ECU CONTROLLED
SYSTEMS
26 Author: Date:
2005 SEQUOIA (RM1146U)
2. SYMPTOM CONFIRMATION AND DIAGNOSTIC TROUBLE CODE CHECK
The diagnostic system in the SEQUOIA fulfills various functions. The first function is the Diagnostic Trouble
Code Check in which a malfunction in the signal circuits to the ECU is stored in code in the ECU memory
at the time of occurrence, to be output by the technician during troubleshooting. Another function is the Input
Signal Check which checks if the signals from various switches are sent to the ECU correctly.
By using these check functions, the problem areas can be narrowed down quickly and troubleshooting can
be performed effectively. Diagnostic functions are incorporated in the following systems in the SEQUOIA.
SystemDiagnostic Trouble
Code CheckInput Signal Check
(Sensor Check)Diagnostic Test
Mode (Active Test)
1. Engine(with Check
Mode)
2. Automatic Transmission(with Check
Mode)
3. Air Suspension Control System(with Check
Mode)
4. Tire Pressure Warning System
5. ABS with EBD & BA & TRAC & VSC System
6. Can Communication System
7. Supplemental Restraint System(with Check
Mode)
8. Power Seat Control System w/ Driving Position Memory
9. Cruise Control System
10.Engine Immobilizer System
11. Combination Meter System
12.Sliding Roof System
13.Body Control System
14.Driver Door Control System
15.Passenger Door Control System
16.Back Door Control System
17.Multiplex Communication System
18.Audio System
19.Rear Seat Audio System
20.Rear Seat Entertainment System
21.Air Conditioning System
In diagnostic trouble code check, it is very important to determine whether the problem indicated by the diag-
nostic trouble code is still occurring or occurred in the past but returned to normal at present. In addition,
it must be checked in the problem symptom check whether the malfunction indicated by the diagnostic
trouble code is directly related to the problem symptom or not. For this reason, the diagnostic trouble codes
should be checked before and after the symptom confirmation to determine the current conditions, as shown
in the table on the next page. If this is not done, it may, depending on the case, result in unnecessary trouble-
shooting for normally operating systems, thus making it more difficult to locate the problem, or in repairs not
pertinent to the problem. Therefore, always follow the procedure in correct order and perform the diagnostic
trouble code check.

DI±72
± DIAGNOSTICSENGINE
266 Author: Date:
2005 SEQUOIA (RM1146U)P2445
(DI±426)
Secondary Air Injection System
Pump Stuck On Bank 1

Air pump fuse

Vacuum hose

Air pump assembly

Open in air pump circuit

Air injection system piping

Pressure sensor

Open or short in pressure sensor circuit

ECM

P2610
(DI±442)ECM/PCM Internal Engine Off
Timer Performance
ECM
P2714
(DI±656)Pressure Control Solenoid ºDº
Performance (Shift Solenoid
Valve SLT)

Electronic control automatic transmission (ECT)
P2716
(DI±662)Pressure Control Solenoid ºDº
Electrical (Shift Solenoid Valve
SLT)

Electronic control automatic transmission (ECT)
P2740
(DI±666)Transmission Fluid Temperature
Sensor ºBº Circuit
Electronic control automatic transmission (ECT)
P2742
(DI±666)Transmission Fluid Temperature
Sensor ºBº Circuit Low Input
Electronic control automatic transmission (ECT)
2743
(DI±666)Transmission Fluid Temperature
Sensor ºBº Circuit High Input
Electronic control automatic transmission (ECT)
P2757
(DI±672)
Torque Converter clutch Pres-
sure Control Solenoid Perfor-
mance (Shift Solenoid Valve
SLU)

Electronic control automatic transmission (ECT)
P2759
(DI±680)Torque Converter clutch Pres-
sure Control Solenoid Electrical
(Shift Solenoid Valve SLU)

Electronic control automatic transmission (ECT)
P2772
(DI±685)Transfer L4 SW Circuit
Electronic control automatic transmission (ECT)
P2A00
(DI±451)A/F Sensor Circuit Slow Re-
sponse (Bank 1 Sensor 1)
Open or short in A/F sensor (sensor 1) circuit

A/F sensor (sensor 1)

ECM

P2A03
(DI±451)A/F Sensor Circuit Slow Re-
sponse (Bank 2 Sensor 1)
Open or short in A/F sensor (sensor 1) circuit

A/F sensor (sensor 1)

ECM

B2799
(DI±1580)Engine Immobilizer System Mal-
function
Immobilizer system±
U0001
(DI±444)High Speed CAN Communica-
tion Bus
ECM
*1: ± .... MIL does not light up.  .... MIL lights up.
*2: MIL lights up or blinks.

DI±518
± DIAGNOSTICSAUTOMATIC TRANSMISSION
712 Author: Date:
2005 SEQUOIA (RM1146U) Output speed sensor
Output shaft speed sensor
Input speed sensor, Input turbine speed sensor ºAº, Speed
sensor (NT), Turbine speed sensorInput turbine speed sensor
PNP switch, NSWPark/neutral position switch
Pressure control solenoidTransmission pressure control solenoid
Shift solenoidTransmission shift solenoid valve
Transmission control switch, Shift lock control unitShift lock control module
Engine immobilizer system, Immobilizer systemVehicle anti±theft system

I03114
T6
Transponder Key
Amplifier
13
T16Transponder Key ECU
CODE RXCKTXCT
6
5
45
T16
4
T16 Y±G
LG
R±Y RXCK
CODE TXCT
± DIAGNOSTICSENGINE IMMOBILISER SYSTEM
DI±1589
1783 Author: Date:
2005 SEQUOIA (RM1146U)
Code 21 or 22 is not output
CIRCUIT DESCRIPTION
The transponder key ECU outputs DTC 21 while the immobilizer system is deactivated by use of the master
key, and outputs DTC 22 while it is deactivated by use of the sub key.
HINT:
DTCs 21 and 22 are normal codes.
DTC No.
(See Page)DTC Detecting ConditionTrouble Area
21, 22Communication is normal.

Key

Transponder key ECU

Transponder key amplifier with key coil

Wire harness
WIRING DIAGRAM
DIABG±04

± DIAGNOSTICSCOMBINATION METER SYSTEM
DI±1617
1811 Author: Date:
2005 SEQUOIA (RM1146U)
(c) Reconnect the C5 and C6 connectors.
(d) Measure the voltage of each terminal of the wire harness side connector.
Standard:
Terminals No.Wiring ColorTerminal DescriptionConditionSpecified Condition
C5±1 ± Body groundR±B ± Body
groundParking brake signalParking brake warning light ON6.7 to 12 V
C5±1 ± Body groundR±B ± Body
groundParking brake signalParking brake warning light OFFBelow 1 V
C5±2 ± Body groundLG±R ± Body
groundCRUISE signalCRUISE indicator light ONBelow 1 V
C5±2 ± Body groundLG±R ± Body
groundCRUISE signalCRUISE indicator light OFF10 to 14 V
C5±3 ± Body groundB ± Body groundIgnition switch signal
(Start)Ignition switch OFFBelow 1 V
C5±3 ± Body groundB ± Body groundIgnition switch signal
(Start)Ignition switch START10 to 14 V
C5±4 ± Body groundG±Y ± Body
groundSeat belt condition signal
(Driver side)D±BELT indicator light ONBelow 1 V
C5±4 ± Body groundG±Y ± Body
groundSeat belt condition signal
(Driver side)D±BELT indicator light OFF10 to 14 V
C5±13 ± Body groundLG±R ± Body
groundWasher level signalWASH LVL indicator light ONBelow 1 V
C5±13 ± Body groundLG±R ± Body
groundWasher level signalWASH LVL indicator light OFF10 to 14 V
C5±14 ± Body groundL±O ± Body
groundO/D OFF indicator signalO/D OFF indicator light ONBelow 1 V
C5±14 ± Body groundL±O ± Body
groundO/D OFF indicator signalO/D OFF indicator light OFF10 to 14 V
C5±15 (*1) ± Body groundY±R ± Body
groundA/T oil temperature signalA/T OIL TEMP. warning light ONBelow 1 V
C5±15 (*1) ± Body groundY±R ± Body
groundA/T oil temperature signalA/T OIL TEMP. warning light OFF10 to 14 V
C5±16 ± Body groundLG±B ± Body
groundSecurity indicator light
signal (Engine immobilizer
system)
Security indicator light ON10 to 14 V
C5±16 ± Body groundLG±B ± Body
groundSecurity indicator light
signal (Engine immobilizer
system)
Security indicator light OFFBelow 1 V
C5±17 ± Body groundGR ± Body
groundSecurity indicator light
signal (Theft deterrent
system)
Security indicator light ON10 to 14 V
C5±17 ± Body groundGR ± Body
groundSecurity indicator light
signal (Theft deterrent
system)
Security indicator light OFFBelow 1 V
C5±18 ± Body groundV±W ± Body
groundCHECK ENGINE signalCHECK ENGINE warning light ONBelow 1 V
C5±18 ± Body groundV±W ± Body
groundCHECK ENGINE signalCHECK ENGINE warning light OFF10 to 14 V
C5±19 ± Body groundG±B ± Body
groundA/T shift position signal
(L)A/T L indicator OFFBelow 1 V

I18742
Body ECU
IEW±BIND 12
A17
BR
J8
J/CGR 9
1F 1D6
C6C5 Combination Meter
16
B5 Security Instrument Panel J/B
± DIAGNOSTICSBODY CONTROL SYSTEM
DI±1731
1925 Author: Date:
2005 SEQUOIA (RM1146U)
Theft deterrent indicator circuit
CIRCUIT DESCRIPTION
When the theft deterrent system is preparing to set, this circuit turns on the indicator light. When the system
has been set, it continually turns the indicator light on for 1 second and turns it off for 1 second, and thus
blinking the indicator light.
This theft deterrent indicator sends a key judgment of the immobilizer to the transponder key ECU.
WIRING DIAGRAM
DI579±09

ST08X±03
± STARTINGSTARTING SYSTEM
ST±1
2875 Author: Date:
2005 SEQUOIA (RM1146U)
STARTING SYSTEM
ON±VEHICLE INSPECTION
NOTICE:
Before changing the starter, check these items again:

Connector connection

Accessory installation, e.g.: engine immobilizer system