2007 TOYOTA SIENNA ECU

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

IG–62GR-FE IGNITION – IGNITION COIL AND SPARK PLUG
IG
ON-VEHICLE INSPECTION
NOTICE:
In this section, the terms "cold" and "hot" refer to the
temperature of the coils. "Cold" means approximately -
10
C (14F) to 50C (122F). "Hot" means approximately
50
C (122F) to 100C (212F).
1. INSPECT IGNITION COIL ASSEMBLY
(a) Check for DTCs.
NOTICE:
If any DTC is present, perform troubleshooting
in accordance with the procedures for that DTC.
(b) Remove the ignition coil assembly and spark plug.
(See page IG-8).
(c) Check that sparks occur.
(1) Disconnect the 6 fuel injector connectors.
(2) Install the spark plugs to each ignition coil, and
connect the ignition coil connectors.
(3) Ground the spark plugs.
(4) Check if a spark occurs at each spark plug
while the engine is being cranked.
NOTICE:
• Be sure to ground the spark plugs when
checking.
• Replace the ignition coil if it receives an
impact.
• Do not crank the engine for more than 2
seconds.
(d) Perform the spark test according to the flowchart
below.
(1) Check that the ignition coil connector is
securely connected.
Result
(2) Perform a spark test on each ignition coil.
1. Replace the ignition coil with a normal one.
2. Perform the spark test again.
Result
A133895
A133897
Result Proceed to
NG Connect securely
OK Go to next step
Result Proceed to
NG Go to next step
OK Replace ignition coil

ST–62GR-FE STARTING – STARTER
ST
(c) Remove the 2 bolts and the starter.
DISASSEMBLY
1. REMOVE REPAIR SERVICE STARTER KIT
(a) Remove the nut and disconnect the lead wire from
the repair service starter kit.
(b) Remove the 2 screws which are used to secure the
repair service starter kit to the repair service starter
kit.
(c) Remove the repair service starter kit.
(d) Remove the return spring and the plunger from the
repair service starter kit.
2. REMOVE STARTER YOKE ASSEMBLY
(a) Remove the 2 through bolts and pull out the starter
yoke together with the starter commutator end
frame.
(b) Remove the starter yoke from the starter
commutator end frame.
A160252
A079718
A079719
A079720
A079721

DRIVE SHAFT – FRONT DRIVE SHAFTDS–7
DS
12. REMOVE FRONT DRIVE SHAFT ASSEMBLY RH (for
4WD)
(a) Using SST, remove the front drive shaft assembly
RH.
SST 09520-01010, 09520-24010 (09520-32040)
HINT:
Overhaul the side following the same procedures as
for the LH side.
NOTICE:
• When removing and installing the front drive
shaft assembly RH in 4WD vehicle, be sure to
first drain all the transaxle oil and transfer oil.
If removal and installation is carried out
without draining these oils, the transfer oil
will flow into the transaxle side. Extensive
cleaning will be required if the two oils mix.
• Do not damage the oil seal and dust cover.
• Move the drive shaft assembly while keeping
it level.
13. SECURE FRONT AXLE ASSEMBLY
NOTICE:
The hub bearing could be damaged if it is subjected
to the vehicle weight, such as when moving the
vehicle with the drive shaft removed. Therefore, if it
is absolutely necessary to place the vehicle weight
on the hub bearing, first support it with SST.
SST 09608-16042 (09608-02021, 09608-02041)
C108268E04
C054583E01

TW–4TIRE AND WHEEL – TIRE AND WHEEL SYSTEM
TW
4. INSPECT WHEEL BALANCE (for Non-steel Wheel)
(a) Check and adjust the off-the-car balance.
Imbalance after adjustment:
8.0 g (0.018 lb.) or less.
NOTICE:
• Use a cleaning detergent to remove dirt, oil
and water from the surface where the balance
weight is to be adhered.
• Do not touch the sticking surface of the tape.
• Adhere the sticking type balance weight to
the flat position shown in the illustration.
• Push the balance weight securely with a
finger to adhere it to the position.
• Do not reuse the balance weight.
HINT:
• The inner side balance weight should be installed
by clipping it to the rim.
• If necessary, check and adjust the on-the-car
balance.
5. INSPECT FRONT AXLE HUB BEARING LOOSENESS
HINT:
See page AH-5.
6. INSPECT REAR AXLE HUB BEARING LOOSENESS
(for 2WD)
HINT:
See page AH-16.
7. INSPECT REAR AXLE HUB BEARING LOOSENESS
(for 4WD)
HINT:
See page AH-19.
8. INSPECT FRONT AXLE HUB RUNOUT
HINT:
See page AH-5.
9. INSPECT REAR AXLE HUB RUNOUT (for 2WD)
HINT:
See page AH-16.
10. INSPECT REAR AXLE HUB RUNOUT (for 4WD)
HINT:
See page AH-19.
C144018E01