TOYOTA SIENNA 2007 Service Workshop Manual

INTRODUCTION – HOW TO TROUBLESHOOT ECU CONTROLLED SYSTEMSIN–39
IN
• In the DTC check, it is very important to determine
whether the problem indicated by the DTC either: 1)
still occurs, or 2) occurred in the past but has returned
to normal. In addition, the DTC should be compared
to the problem symptom to see if they are related. For
this reason, DTCs should be checked before and after
confirmation of symptoms (i.e., whether or not
problem symptoms exist) to determine current system
conditions, as shown in the flowchart below.
• Never skip the DTC check. Failing to check DTCs
may, depending on the case, result in unnecessary
troubleshooting for systems operating normally or
lead to repairs not related to the problem. Follow the
procedures listed in the flowchart in the correct order.
Theft Deterrent System XXXXX
Engine Immobiliser System
XX
Cruise Control SystemXXX
Dynamic Laser Cruise Control System
XXX
Lighting System
XX
Wiper and Washer SystemXXXXX
Power Door Lock Control System X X X
Wireless Door Lock Control SystemXX
Key Reminder Warning System X X XX
Meter / Gauge System X X X
Audio and Visual SystemXXXX
Rear Seat Entertainment System XXXXX
Navigation System
XXXX
Clearance Sonar SystemXXXXX
Rear View Monitor System XXXXX
Power Window Control System (with Jam
Protection Function)XXX
Power Window Control System (without Jam
Protection Function)XXXXX
Power Mirror Control System (with Memory) X X X
Power Mirror Control System (without Memory)XXXXX
Front Power Seat Control System X X X
Rear No. 2 Seat Assembly (with Power Stowing
Function)XXXXX
Window Deogger SystemXXXXX
Power Slide Door System
XX
Slide Door Closer System X X X
Back Door Closer SystemXX
Power Back Door SystemXX
Sliding Roof System XXXXX
Multiplex Communication System XXXXX
CAN Communication System XXXXXSystemSYMPTOM CONFIRMATION AND DIAGNOSTIC TROUBLE CODE
DTC Check
(Normal Mode)DTC Check
(Check Mode)Sensor Check/
Test Mode
(Input Signal
Check)Data List Active Test

IN–40INTRODUCTION – HOW TO TROUBLESHOOT ECU CONTROLLED SYSTEMS
IN
• The following flowchart shows how to proceed with
troubleshooting using the DTC check. Directions from
the flowchart will indicate how to proceed either to
DTC troubleshooting or to the troubleshooting of each
problem symptom.
NEXT
NEXT
Result
B
A
NEXT
Result
B
A
Result
1DTC CHECK
2MAKE A NOTE OF DTCS DISPLAYED AND THEN CLEAR MEMORY
3SYMPTOM CONFIRMATION
Result Proceed to
No symptoms exist A
Symptoms exist B
Go to step 5
4SIMULATION TEST USING SYMPTOM SIMULATION METHODS
5DTC CHECK
Result Proceed to
DTC is not output A
DTC is output B
TROUBLESHOOTING OF PROBLEM
INDICATED BY DTC
6SYMPTOM CONFIRMATION
Result Proceed to
No symptoms exist A
Symptoms exist B

INTRODUCTION – HOW TO TROUBLESHOOT ECU CONTROLLED SYSTEMSIN–41
IN
If a DTC was displayed in the initial DTC check, the
problem may have occurred in a wire harness or
connector in that circuit in the past. Check the wire
harness and connectors.
B
A
The problem still occurs in a place other than the diagnostic
circuit (the DTC displayed first is either for a past problem or
a secondary problem).
4. SYMPTOM SIMULATION
HINT:
The most difficult case in troubleshooting is when no
problem symptoms occur. In such a case, a thorough
problem analysis must be carried out. A simulation of the
same or similar conditions and environment in which the
problem occurred in the customer's vehicle should be
carried out. No matter how much skill or experience a
technician has, troubleshooting without confirming the
problem symptoms will lead to important repairs being
overlooked and mistakes or delays.
For example:
With a problem that only occurs when the engine is
cold or as a result of vibration caused by the road
during driving, the problem can never be
determined if the symptoms are being checked on
a stationary vehicle or a vehicle with a warmed-up
engine. Vibration, heat or water penetration
(moisture) is difficult to reproduce. The symptom
simulation tests below are effective substitutes for
the conditions and can be applied on a stationary
vehicle. Important points in the symptom
simulation test:
In the symptom simulation test, the problem
symptoms as well as the problem area or parts
must be confirmed. First, narrow down the
possible problem circuits according to the
symptoms. Then, connect the tester and carry out
the symptom simulation test, judging whether the
circuit being tested is defective or normal. Also,
confirm the problem symptoms at the same time.
Refer to the problem symptoms table for each
system to narrow down the possible causes.SYSTEM NORMAL
TROUBLESHOOTING OF EACH PROBLEM SYMPTOM

IN–42INTRODUCTION – HOW TO TROUBLESHOOT ECU CONTROLLED SYSTEMS
IN
(a) VIBRATION METHOD: When a malfunction seems
to occur as a result of vibration.
(1) PART AND SENSOR
Apply slight vibration with a finger to the part of
the sensor suspected to be the cause of the
problem, and check whether or not the
malfunction occurs.
NOTICE:
Applying strong vibration to relays may open
relays.
(2) CONNECTORS
Slightly shake the connector vertically and
horizontally.
(3) WIRE HARNESS
Slightly shake the wire harness vertically and
horizontally.
HINT:
The connector joint and fulcrum of the vibration
are the major areas that should be checked
thoroughly.
(b) HEAT METHOD: When a malfunction seems to
occur when the area in question is heated.
(1) Heat the component that is the possible cause of
the malfunction with a hair dryer or similar
device. Check if the malfunction occurs.
NOTICE:
• Do not heat to more than 60
C (140F).
Exceeding this temperature may damage
the components.
• Do not apply heat directly to the parts in
the ECU.
(c) WATER SPRINKLING METHOD: When a
malfunction seems to occur on a rainy day or in
high-humidity.
(1) Sprinkle water onto the vehicle and check if the
malfunction occurs.
NOTICE:
• Never sprinkle water directly into the
engine compartment. Indirectly change
the temperature and humidity by spraying
water onto the front of the radiator.
• Never apply water directly onto the
electronic components.
HINT:
If the vehicle has or had a water leakage
problem, the leakage may have damaged the
ECU or connections. Look for evidence of
corrosion or short circuits. Proceed with caution
during water tests.B071602E03
D025085E02

INTRODUCTION – HOW TO TROUBLESHOOT ECU CONTROLLED SYSTEMSIN–43
IN
(d) HIGH ELECTRICAL LOAD METHOD: When a
malfunction seems to occur when electrical load is
excessive.
(1) Turn on the heater blower, headlight, rear
window defogger and all other electrical loads.
Check if the malfunction reoccurs.
5. DIAGNOSTIC TROUBLE CODE CHART
Look for output Diagnostic Trouble Codes (DTCs) (from the
DTC checks) in the appropriate section's Diagnostic Trouble
Code Chart. Use the chart to determine the trouble area and
the proper inspection procedure. A description of each of the
chart's columns is shown in the table below.
6. PROBLEM SYMPTOMS TABLE
When a "Normal" code is output during a DTC check but
the problem still occurs, use the Problem Symptoms
Table. The suspected areas (circuits or parts) for each
problem symptoms are in the table. The suspected areas
are listed in order of probability. A description of each of
the chart's columns is shown in the table below.
HINT:
In some cases, the problem is not detected by the
diagnostic system even though a problem symptom
occurs. It is possible that the problem is occurring
outside the detection range of the diagnostic system, or
that the problem occurs in a completely different system.
7. CIRCUIT INSPECTION
A description of the main areas of each circuit inspection
is shown in the table below.
B107149
Item Description
DTC No. Indicates the diagnostic trouble code
Detection Item Indicates the system or details of the problem
Trouble Area Indicates the suspect areas of the problem
See Page Indicates the page where the inspection procedures for each circuit is
to be found, or gives instruction for checking and repairs.
Item Description
Problem Symptom -
Circuit Inspection, Inspection Order Indicates the order in which the circuits need to be checked
Circuit or Part Name Indicates the circuit or part which needs to be checked
See Page Indicates the page where the flowchart for each circuit is located
Item Description
Circuit Description The major role, operation of the circuit and its component parts are
explained.
Diagnostic Trouble Code No. and Detection item Indicates the diagnostic trouble codes, diagnostic trouble code
settings and suspected areas for a problem
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.

IN–44INTRODUCTION – HOW TO TROUBLESHOOT ECU CONTROLLED SYSTEMS
IN
Inspection Procedures Use the inspection procedures to determine if the circuit is normal or
abnormal. If abnormal, use the inspection procedures to determine
whether the problem is located in the sensors, actuators, wire
harnesses or ECU.
Indicates the condition of the connector of the ECU during the check Connector being checked is connected.
Connections of tester are indicated by (+) or (-) after the terminal
name.
Connector being checked is disconnected.
The inspections between a connector and body ground, information
about the body ground is not shown in the illustration. Item Description

IN–50INTRODUCTION – TERMS
IN
GLOSSARY OF SAE AND TOYOTA
TERMS
This glossary lists all SAE-J1930 terms and abbreviations
used in this manual in compliance with SAE
recommendations, as well as their TOYOTA equivalents.
SAE
ABBREVIATIONSSAE TERMSTOYOTA TERMS
( )-ABBREVIATIONS
A/C Air Conditioning Air Conditioner
ACL Air Cleaner Air Cleaner, A/CL
AIR Secondary Air Injection Air Injection (AI)
AP Accelerator Pedal -
B+ Battery Positive Voltage +B, Battery Voltage
BARO Barometric Pressure HAC
CAC Charge Air Cooler Intercooler
CARB Carburetor Carburetor
CFI Continuous Fuel Injection -
CKP Crankshaft Position Crank Angle
CL Closed Loop Closed Loop
CMP Camshaft Position Cam Angle
CPP Clutch Pedal Position -
CTOX Continuous Trap Oxidizer -
CTP Closed Throttle Position LL ON, Idle ON
DFI Direct Fuel Injection Direct Injection (DI./INJ)
DI Distributor Ignition -
DLC3 Data Link Connector 3 OBD II Diagnostic Connector
DTC Diagnostic Trouble Code Diagnostic Trouble Code
DTM Diagnostic Test Mode -
ECL Engine Coolant Level -
ECM Engine Control Module Engine Electronic Control Unit (ECU)
ECT Engine Coolant Temperature Coolant Temperature, Water Temperature (THW)
EEPROM Electrically Erasable Programmable Read Only MemoryElectrically Erasable Programmable Read Only
Memory (EEPROM), Erasable Programmable Read
Only Memory (EPROM)
EFE Early Fuel Evaporation Cold Mixture Heater (CMH), Heat Control Valve (HCV)
EGR Exhaust Gas Recirculation Exhaust Gas Recirculation (EGR)
EI Electronic Ignition Distributorless Ignition (DLI)
EM Engine Modification Engine Modification (EM)
EPROM Erasable Programmable Read Only Memory Programmable Read Only Memory (PROM)
EVAP Evaporative Emission Evaporative Emission Control (EVAP)
FC Fan Control -
FEEPROMFlash Electrically Erasable Programmable Read Only
Memory-
FEPROM Flash Erasable Programmable Read Only Memory -
FF Flexible Fuel -
FP Fuel Pump Fuel Pump
GEN Generator Alternator
GND Ground Ground (GND)
HO2S Heated Oxygen SensorHeated Oxygen Sensor (HO
2S)
IAC Idle Air Control Idle Speed Control (ISC)
IAT Intake Air Temperature Intake or Inlet Air Temperature
ICM Ignition Control Module -

INTRODUCTION – TERMSIN–51
IN
IFI Indirect Fuel Injection Indirect Injection (IDL)
IFS Inertia Fuel-Shutoff -
ISC Idle Speed Control -
KS Knock Sensor Knock Sensor
MAF Mass Airflow Air Flow Meter
MAP Manifold Absolute Pressure Manifold Pressure Intake Vacuum
MC Mixture ControlElectric Bleed Air Control Valve (EBCV)
Mixture Control Valve (MCV)
Electric Air Control Valve (EACV)
MDP Manifold Differential Pressure -
MFI Multiport Fuel Injection Electronic Fuel Injection (EFI)
MIL Malfunction Indicator Light Check Engine Light
MST Manifold Surface Temperature -
MVZ Manifold Vacuum Zone -
NVRAM Non-Volatile Random Access Memory -
O2S Oxygen SensorOxygen Sensor, O
2 Sensor (O2S)
OBD On-Board Diagnostic On-Board Diagnostic System (OBD)
OC Oxidation Catalytic Converter Oxidation Catalytic Convert (OC), CCo
OL Open Loop Open Loop
PAIR Pulsed Secondary Air Injection Air Suction (AS)
PCM Powertrain Control Module -
PNP Park/Neutral Position -
PROM Programmable Read Only Memory -
PSP Power Steering Pressure -
PTOX Periodic Trap OxidizerDiesel Particulate Filter (DPF)
Diesel Particulate Trap (DPT)
RAM Random Access Memory Random Access Memory (RAM)
RM Relay Module -
ROM Read Only Memory Read Only Memory (ROM)
RPM Engine Speed Engine Speed
SC Supercharger Supercharger
SCB Supercharger Bypass E-ABV
SFI Sequential Multiport Fuel Injection Electronic Fuel Injection (EFI), Sequential Injection
SPL Smoke Puff Limiter -
SRI Service Reminder Indicator -
SRT System Readiness Test -
ST Scan Tool -
TB Throttle Body Throttle Body
TBI Throttle Body Fuel InjectionSingle Point Injection
Central Fuel Injection (Ci)
TC Turbocharger Turbocharger
TCC Torque Converter Clutch Torque Converter
TCM Transmission Control Module Transmission ECU, ECT ECU
TP Throttle Position Throttle Position
TR Transmission Range -
TVV Thermal Vacuum ValveBimetallic Vacuum Switching Valve (BVSV)
Thermostatic Vacuum Switching Valve (TVSV)
TWC Three-Way Catalytic ConverterThree-Way Catalytic (TWC)
Manifold Converter
CC
RO
SAE
ABBREVIATIONSSAE TERMSTOYOTA TERMS
( )-ABBREVIATIONS

IN–52INTRODUCTION – TERMS
IN
TWC+OC Three-Way + Oxidation Catalytic ConverterCCR + CCo
VAF Volume Airflow Air Flow Meter
VR Voltage Regulator Voltage Regulator
VSS Vehicle Speed Sensor Vehicle Speed Sensor
WOT Wide Open Throttle Full Throttle
WU-OC Warm Up Oxidation Catalytic Converter -
WU-TWC Warm Up Three-Way Catalytic Converter -
3GR Third Gear -
4GR Fourth Gear -SAE
ABBREVIATIONSSAE TERMSTOYOTA TERMS
( )-ABBREVIATIONS

IN–30INTRODUCTION – HOW TO TROUBLESHOOT ECU CONTROLLED SYSTEMS
IN
HOW TO TROUBLESHOOT ECU
CONTROLLED SYSTEMS
GENERAL INFORMATION
A large number of ECU controlled systems are used in the
SIENNA. In general, ECU controlled systems are considered
to be very intricate, requiring a high level of technical
knowledge to troubleshoot. However, most problem checking
procedures only involve inspecting the ECU controlled
system's circuits one by one. An adequate understanding of
the system and a basic knowledge of electricity is enough to
perform effective troubleshooting, accurate diagnoses and
necessary repairs.
FOR USING INTELLIGENT TESTER
– Before using the intelligent tester, read the tester
operator's manual thoroughly.
– If the tester cannot communicate with the ECU controlled
systems when the tester is connected to the DLC3 with the
ignition switch on and the tester turned on, there is a
problem on the vehicle side or tester side.
(1) If communication is normal when the tester 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 tester is
connected to another vehicle, the problem is probably
in the tester itself. Perform the Self Test procedures
outlined in the tester operator's manual.