2001 TOYOTA SEQUOIA stop start

V07268
VIBRATION METHOD: When vibration seems to be the major cause.
CONNECTORS
WIRE HARNESS
PARTS AND SENSOR1
Slightly shake the connector vertically and horizontally.
Slightly shake the wire harness vertically and horizontally.
The connector joint, fulcrum of the vibration, and body
through portion are the major areas to be checked thorough-
ly.
Apply slight vibration with a finger to the part of the sensor
considered to be the problem cause and check that the mal-
function occurs.Shake Slightly
Swing Slightly
Vibrate Slightly
HINT:
Applying strong vibration to relays may result in open relays.
± INTRODUCTIONHOW TO TROUBLESHOOT ECU CONTROLLED
SYSTEMSIN±29
29 Author: Date:
2005 SEQUOIA (RM1146U)
3. SYMPTOM SIMULATION
The most difficult case in troubleshooting is when there are no problem symptoms occurring. In such cases,
a thorough customer problem analysis must be carried out, then simulate the same or similar conditions and
environment in which the problem occurred in the customer's vehicle. No matter how much experience a
technician has, or how skilled he may be, if he proceeds to troubleshoot without confirming the problem
symptoms he will tend to overlook something important in the repair operation and make a wrong guess
somewhere, which will only lead to a standstill. For example, for a problem which only occurs when the en-
gine is cold, or for a problem which occurs due to vibration caused by the road during driving, etc., the prob-
lem can never be determined so long as the symptoms are confirmed with the engine hot or the vehicle at
a standstill. Since vibration, heat or water penetration (moisture) is likely cause for problem which is difficult
to reproduce, the symptom simulation tests introduced here are effective measures in that the external
causes are applied to the vehicle in a stopped condition.
Important Points in the Symptom Simulation Test:
In the symptom simulation test, the problem symptoms should be confirmed, but the problem area or parts
must also be found out. To do this, narrow down the possible problem circuits according to the symptoms
before starting this test and connect a tester beforehand. After that, carry out the symptom simulation test,
judging whether the circuit being tested is defective or normal and also confirming the problem symptoms
at the same time. Refer to the problem symptoms table for each system to narrow down the possible causes
of the symptom.

DID7S±01
DI±12
± DIAGNOSTICSENGINE
206 Author: Date:
2005 SEQUOIA (RM1146U)
BASIC INSPECTION
When the malfunction is not confirmed in the DTC check, troubleshooting should be carried out in all the
possible circuits considered as causes of the problem. In many cases, by carrying out the basic engine check
shown in the following flowchart, the location causing the problem can be found quickly and efficiently. There-
fore, using this check is essential in the engine troubleshooting.
1 Is battery voltage 11 V or more when engine stopped?
NO Charge or replace battery.
YES
2 Is engine cranked?
NO Proceed to page ST±15 and continue to trouble-
shoot.
YES
3 Does engine start?
NO Go to step 6.
YES

A23510
Vehicle Speed
(64 km/h and 113 km/h)Between
40 mph and 70 mph
Idling
Ignition Switch OFF
10 minutes
Time Warm up
(Note: Even when vehicle stops during driving pattern, test can be resumed)NOTICE:
This test will not be completed
if the vehicle is driven under
absolute constant speed
condition such as with cruise
control activated. (6)
(5) DI±28
± DIAGNOSTICSENGINE
222 Author: Date:
2005 SEQUOIA (RM1146U)
2. CATALYST MONITOR (ACTIVE AIR±FUEL RATIO CONTROL TYPE)
(a) Preconditions
The monitor will not run unless:

The MIL is OFF
(b) Drive Pattern
(1) Connect a hand±held tester or OBD II scan tool to the DLC3.
(2) Turn the ignition switch to ON.
(3) Turn the tester or scan tool ON.
(4) Clear DTCs (where set) (see page DI±43).
(5) Start the engine and warm it up.
(6) Drive the vehicle at between 40 mph and 70 mph (64 km/h and 113 km/h) for at least 10 minutes.
(c) Monitor Status
(1) Check the Readiness Monitor status displayed on the tester or scan tool.
(2) If the status does not switch to COMPL (complete), extend the driving time.

A23544
40 mph (64 km/h)
Idling
IG SW OFF ECT:
75C (167F) or higher
Vehicle Speed
Warming up(5)(6)
10 minutes
or more(7)
10 seconds
or more4 seconds
or moreTime At Least 3 times
(8) (9)
(10) Accelerator Pedal
DepressedAccelerator Pedal
Released (Fuel±cut)
± DIAGNOSTICSENGINE
DI±31
225 Author: Date:
2005 SEQUOIA (RM1146U)
5. AIR±FUEL RATIO (A/F) AND OXYGEN SENSOR (HO2) MONITOR (ACTIVE AIR±FUEL RATIO
CONTROL TYPE)
(a) Preconditions
The monitor will not run unless:

2 minutes or more have elapsed since the engine was started.

The Engine Coolant Temperature (ECT) is 75C (167F) or higher.

Air±fuel ratio feedback control is performed.

Fuel±cut control is performed for 8 seconds or more.
(b) Drive Pattern
(1) Connect the hand±held tester to DLC3.
(2) Turn the ignition switch to ON.
(3) Clear DTCs (see page DI±43).
(4) Start the engine, and warm it up until the ECT reaches 75C (167F) or higher.
(5) Drive the vehicle at 40 mph (64 km/h) or more for at least 10 minutes.
(6) Change the transmission to 2nd gear.
(7) Accelerate the vehicle to 30 mph (48 km/h) or more by depressing the accelerator pedal for at
least 10 seconds.
(8) Soon after performing step (8) above, release the accelerator pedal for at least 4 seconds without
depressing the brake pedal, in order to execute fuel±cut control.
(9) Stop the vehicle and allow the engine to idle for 10 seconds or more.
(10) Allow the vehicle to decelerate until the vehicle speed declines to less than 6 mph (10 km/h).
(11) Repeat steps from (8) through (10) above at least 3 times in one driving cycle.
(c) Monitor Status
(1) Check the Readiness Monitor status displayed on the tester.
(2) If the status does not switch to COMPL (complete), make sure that the preconditions have been
met, and then perform steps from (5) through (11) in Drive Pattern above.

DI±56
± DIAGNOSTICSENGINE
250 Author: Date:
2005 SEQUOIA (RM1146U) VVT CTRL B1
Turn on and off OCV
(Oil Control Valve)ON/OFF

Engine stalls or idles roughly
when OCV turned ON

Normal engine running or idling
when OCV off
VVT CTRL B2Turn on and off OCV
(Oil Control Valve)ON/OFF

Engine stalls or idles roughly
when OCV turned ON

Normal engine running or idling
when OCV off
A/C CUT SIGControl A/C cut signalON/OFF±
FUEL PUMP/SPDActivate fuel pump (C/OPN Relay)ON/OFF±
TC/TE1Turn on and off TC and TE1 con-
nectionON/OFF
ON: TC and TE1 connected

OFF: TC and TE1 disconnected
FC IDL PROHBTProhibit idling fuel cut controlON/OFF±
ETCS OPEN SLOWThrottle actuatorON: throttle valve opens slowly
This test is possible when the fol-
lowing conditions are met:

Ignition switch ON

Engine does not start

Fully depressing accelerator ped-
al (APP: 58 degrees or more)
ETCS CLOSE SLOWThrottle actuatorON: throttle valve closes slowlySame as above
ETCS OPEN FASTThrottle actuatorON: throttle valve opens fastSame as above
ETCS CLOSE FASTThrottle actuatorON: throttle valve closes fastSame as above
FUEL CUT #1Cylinder #1 injector fuel cutON/OFFThis test is possible during vehicle
stopping and engine idling.
FUEL CUT #2Cylinder #2 injector fuel cutON/OFFSame as above
FUEL CUT #3Cylinder #3 injector fuel cutON/OFFSame as above
FUEL CUT #4Cylinder #4 injector fuel cutON/OFFSame as above
FUEL CUT #5Cylinder #5 injector fuel cutON/OFFSame as above
FUEL CUT #6Cylinder #6 injector fuel cutON/OFFSame as above
FUEL CUT #7Cylinder #7 injector fuel cutON/OFFSame as above
FUEL CUT #8Cylinder #8 injector fuel cutON/OFFSame as above
VENT VALVE (ALONE)Activate vent valve
(built into pump module)ON/OFF±
VCUUM PUMPActivate vacuum pump
(built into pump module)ON/OFF±

± DIAGNOSTICSENGINE
DI±105
299 Author: Date:
2005 SEQUOIA (RM1146U)
INSPECTION PROCEDURE
HINT:
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 Connect hand±held tester, and read value of mass air flow rate.
PREPARATION:
(a) Connect the hand±held tester to the DLC3.
(b) Turn the ignition switch to 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 / MAF.
CHECK:
Read the mass air flow rate on the hand±held tester.
RESULT:
Air Flow Rate (gm/s)Proceed to
0.0A
271.0 or moreB
Between 1 and 270.0 (*1)C
*1: The value must change when the throttle valve is opened or closed.
B Go to step 6.
C Check for intermittent problems
(See page DI±11).
A

DI±126
± DIAGNOSTICSENGINE
320 Author: Date:
2005 SEQUOIA (RM1146U)
TYPICAL ENABLING CONDITIONS
ItSpecificationItemMinimumMaximum
The monitor will run whenever this DTC is
not presentSee page DI±18
Case 1 (When temperature is fixed between 35C (95F) and 60C (140F)):
Cumulative idle off period250 sec.±
Speed increase 30 km/h (18.6 mph) or
more10 times±
Engine coolant temperature35C (95F)60C (140F)
Intake air temperature±6.7C (20F)±
Case 2 (When temperature is fixed at 60C (140F) or more):
Engine coolant temperature at engine
start60C (140F)±
Intake air temperature±6.7C (20F)±
Stop and goOnce or more (Stop for 20 sec. or more and accelerate to more than 70 km/h (43.5 mph)
with in 40 sec.)
Steady driving and stop *Once or more
*: Vehicle is driven by 65 km/h (40.4 mph) or more for 30 sec. or more and the vehicle speed reaches 70
km/h (43.5 mph). The vehicle is decelerated from 65 km/h (40.4 mph) to 3 km/h (1.86 mph) or less within
35 sec. and stopped for 10 sec.
TYPICAL MALFUNCTION THRESHOLDS
Detection CriteriaThreshold
Case1 (When temperature is fixed between 35C (95F) and 60C (140F)):
Change of engine coolant temperature valueLess than 3C (5.4F)
Case2 (When temperature is fixed at 60C (140F) or more):
Change of engine coolant temperature value1C (1.8F) or less
COMPONENT OPERATING RANGE
Standard Value
Engine coolant temperature changes with the actual engine coolant temperature.
INSPECTION PROCEDURE
HINT:

If DTC P0115, P0116, P0117, P0118 and P0125 are output simultaneously, ECT sensor circuit may
be open or shorted. Perform the troubleshooting of DTC P0115, P0117 or P0118 first.

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.
Replace engine coolant temperature sensor.

DI±140
± DIAGNOSTICSENGINE
334 Author: Date:
2005 SEQUOIA (RM1146U)
TYPICAL ENABLING CONDITIONS
ItSpecificationItemMinimumMaximum
The monitor will run whenever this DTC is
not presentSee page DI±18
Fuel cutOFF
EngineRunning
TYPICAL MALFUNCTION THRESHOLDS
Detection CriteriaThreshold
Time until ºengine coolant temperatureº detection temperature reaches feedback start temperature
When the temperature at the time of engine starting is
±8.34°C (17°F) or moreEngine coolant temperature is less than ºclosed±loop enable temperatureº
when 2 min. or more after engine start
When the temperature at the time of engine starting is
±19.45 to ±8.34°C (±3 to 17°F)Engine coolant temperature is less than ºclosed±loop enable temperatureº
when 5 min. or more after engine start
When the temperature at the time of engine starting is
±19.45°C (±3°F) or lessEngine coolant temperature is less than ºclosed±loop enable temperatureº
when 20 min. or more after engine start
INSPECTION PROCEDURE
HINT:

If DTC P0115, P0116, P0117, P0118 and P0125 are output simultaneously, engine coolant tempera-
ture sensor circuit may be open or short. Perform the troubleshooting of DTC P0115, P0117 or P0118
first.

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 DTC P0125) 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 DTCs using the hand±held tester.
RESULT:
Display (DTC output)Proceed to
P0125A
ºP0125º and other DTCsB
HINT:
If any other codes besides ºP0125º are output, perform the troubleshooting for those DTCs first.
B Go to relevant DTC chart (See page DI±58).
A