2001 TOYOTA SEQUOIA ECU

DI±440
± DIAGNOSTICSENGINE
634 Author: Date:
2005 SEQUOIA (RM1146U)
13 Check whether DTC output recurs.
PREPARATION:
(a) Start the engine and warm it up.
(b) Turn the ignition switch OFF.
(c) Connect a hand±held tester to the DLC3.
(d) Turn the ignition switch to ON and turn the tester ON.
(e) Clear the DTCs (see page DI±43).
(f) Start the engine.
CHECK:
(a) Perform SYSTEM CHECK to operate the air injection system.
Select the following menu items: DIAGNOSIS/ENHANCED OBD II/SYSTEM CHECK/AIR INJ
CHECK/AUTOMATIC OPERATION
(b) After operating secondary air injection system, confirm the pending codes of the secondary air injec-
tion system by selecting the following menu items: DIAGNOSIS / ENHANCED OBD II / DTC INFO /
PENDING CODES.
(c) Read DTC and check no DTC.
OK:
DTC P2444 or P2445 for the secondary air injection system is not output.
NG Check for intermittent problems
(See page DI±11).
OK
END

± DIAGNOSTICSENGINE
DI±443
637 Author: Date:
2005 SEQUOIA (RM1146U)
TYPICAL ENABLING CONDITIONS
ItSpecificationItemMinimumMaximum
The monitor will run whenever these
DTCs are not presentSee page DI±18
Battery voltage8 V±
Ignition switchON
StarterOFF
EngineRunning
TYPICAL MALFUNCTION THRESHOLDS
Detection CriteriaThreshold
Soak time measurement when ECM CPU clock counts 10
min.Less than 7 min., or more than 13 min.
INSPECTION PROCEDURE
HINT:

DTC P2610 is set if an internal ECM problem is detected. Diagnostic procedures are not required. ECM
replacement is required.

Read freeze frame data using a hand±held tester. Freeze frame data record the engine condition when
malfunctions are detected. When troubleshooting, freeze frame data can help determine if the vehicle
was moving or stationary, if the engine was warmed up or not, if the air±fuel ratio was lean or rich, and
other data, from the time the malfunction occurred.
1 Replace ECM (See page SF±80).
NEXT
Check whether DTC output recurs.
(a) Connect a hand±held tester to the DLC3.
(b) Turn the ignition switch to ON.
(c) Clear DTCs (see page DI±43).
(d) Start the engine and wait for 10 minutes or more.
(e) On the tester, select the following menu items: DIAGNOSIS / ENHANCED OBD II / DTC INFO / PEND-
ING CODES.
(f) If no pending DTC is displayed, the repair has been successfully completed.

DI±444
± DIAGNOSTICSENGINE
638 Author: Date:
2005 SEQUOIA (RM1146U)
DTC U0001 High Speed Can Communication Circuit
CIRCUIT DESCRIPTION
The engine control unit and the transmission control unit are located inside the ECM. The engine control unit
intercommunicates with the transmission control ECU with the Controller Area Network (CAN).
If there is a problem in this intercommunication, the ECM sets a DTC.
DTC No.DTC Detection ConditionTrouble Area
U0001
The following conditions are met for 2 seconds (1 trip detection
logic):
(a) Ignition switch ON
(b) Battery voltage is 10 V or more
(c) No intercommunication between engine control ECU and
transmission control ECU
ECM
INSPECTION PROCEDURE
Replace ECM (See page SF±80)
DID8J±01

± DIAGNOSTICSENGINE
DI±449
643 Author: Date:
2005 SEQUOIA (RM1146U)
TYPICAL ENABLING CONDITIONS
ItSpecificationItemMinimumMaximum
The monitor will run whenever these
DTCs are not presentSee page DI±18
Following values are values when atmo-
spheric is 760 mmHg (100 kPa)±
EVAP key±off monitor runs when all of the
following conditions met:±
Atmospheric pressure525 to 825 mmHg (70 to 110 kPa)
Battery voltage10.5 V±
Vehicle speed±4 km/h (2.5 mph)
Ignition switchOFF
Engine conditionNot running
Time after engine stopped5 hours
FTP sensor malfunction (P0450, P0452,
P0453)Not detected
Purge VSVNot operated by scan tool
Vent valveNot operated by scan tool
Leak detection pumpNot operated by scan tool
Both of the following conditions are met
before IG switch OFFCondition 1 and 2
1. Duration that vehicle is driven5 min.±
2. Purge flowExecuted
ECT4.4 to 35°C (40 to 95°F)
IAT4.4 to 35°C (40 to 95°F)
Example of re±start time±
First time7 hours
Second time9 hours and 30 min.
Key±off monitor sequence1 to 8
1. Atmospheric pressure±
Next sequence is run if following condition
set±
Atmospheric pressure change for 10 sec.±2.25 mmHg (0.3 kPa) for 1 sec.
2. First reference pressure±
Next sequence is run if all of following
conditions setCondition 1, 2 and 3
1. FTP when 4 sec. after reference pres-
sure measurement±±7.5 mmHg (±1 kPa)
2. Reference pressure±36.38 to ±7.93 mmHg (±4.85 to ±1.057 kPa)
3. Reference pressureSaturated
3. Vent valve stuck closed check±
Next sequence is run if following condition
set±
FTP change for 10 sec. after vent valve
ON (closed)2.25 mmHg (0.3 kPa)±
4. Vacuum introduction and leak±

± DIAGNOSTICSENGINE
DI±453
647 Author: Date:
2005 SEQUOIA (RM1146U)
TYPICAL ENABLING CONDITIONS
ItSpecificationItemMinimumMaximum
The monitor will run whenever these
DTCs are not presentSee page DI±18
Battery voltage11 V±
ECT75°C (167°F)±
IdleOFF
Engine RPM±4,000 rpm
A/F sensor statusActivated
Fuel cutOFF
Engine load10 to 70%
Estimated catalyst temperature500 to 800°C (932 to 1,472°F)
Shift position2nd±
Catalyst monitorNot executing
Intake air amount2.5 to 12 g/sec
TYPICAL MALFUNCTION THRESHOLDS
Detection CriteriaThreshold
Response rate deterioration levelLess than 0.2 V
Number of average5 or more
MONITOR RESULT
Refer to page DI±26 for detailed information.
The test value and test limit information are described as shown in the following table. Check the monitor
result and test values after performing the monitor drive pattern (refer to ºConfirmation Monitorº).

MID (Monitor Identification Data) is assigned to each emissions±related component.

TID (Test Identification Data) is assigned to each test value.

Scaling is used to calculate the test value indicated on generic OBD ll scan tools.
A/F sensor bank 1 sensor 1
MIDTIDScalingDescription of Test ValueMinimum Test LimitMaximum Test Limit
$01$8EMultiply by 0.0003
(no dimension)Response rate deterioration level for
A/F sensorMalfunction criterionFF
A/F sensor bank 2 sensor 1
MIDTIDScalingDescription of Test ValueMinimum Test LimitMaximum Test Limit
$05$8EMultiply by 0.0003
(no dimension)Response rate deterioration level for
A/F sensorMalfunction criterionFF
WIRING DIAGRAM
Refer to DTC P2195 on page DI±383.

DI±458
± DIAGNOSTICSENGINE
652 Author: Date:
2005 SEQUOIA (RM1146U)
NG Replace or replace harness or connector.
OK
4 Perform confirmation driving pattern.
NEXT
5 Check whether DTC output recurs (DTC P2A00 or P2A03)
CHECK:
(a) On the hand±held tester, select the following menu items: DIAGNOSIS / ENHANCED OBD II / DTC
INFO / PENDING CODES.
(b) Read DTCs.
RESULT:
Display (DTC Output)Proceed To
P2A00 or P2A03A
No outputB
B Check for intermittent problems
(See page DI±11).
A
6 Replace air fuel ratio sensor.
NEXT
7 Perform confirmation driving pattern.
NEXT

± DIAGNOSTICSENGINE
DI±459
653 Author: Date:
2005 SEQUOIA (RM1146U)
8 Check whether DTC output recurs (DTC P2A00 or P2A03)
CHECK:
(a) On the hand±held tester, select the following menu items: DIAGNOSIS / ENHANCED OBD II / DTC
INFO / PENDING CODES.
(b) Read DTCs.
RESULT:
Display (DTC Output)Proceed To
P2A00 or P2A03A
No outputB
A Check air±fuel ratio extremely lean or rich
(See page DI±165).
B
END

DIDIJ±01
± DIAGNOSTICSAUTOMATIC TRANSMISSION
DI±517
711 Author: Date:
2005 SEQUOIA (RM1146U)
TOYOTA PART AND SYSTEM NAME LIST
This reference list indicates the part names used in this manual along with their definitions.
Part and system nameDefinition
Toyota HCAC system, Hydrocarbon adsorptive Catalyst
(HCAC) system, HC adsorptive three±way catalystHC adsorptive three±way catalytic converter
Variable Valve Timing sensor, VVT sensorCamshaft position sensor
Variable valve timing system, VVT systemCamshaft timing control system
Camshaft timing oil control valve, Oil control valve OCV,
VVT, VSVCamshaft timing oil control valve
Variable timing and lift, VVTLCamshaft timing and lift control
Crankshaft position sensor ºAºCrankshaft position sensor
Engine speed sensorCrankshaft position sensor
THAIntake air temperature
Knock control moduleEngine knock control module
Knock sensorEngine knock sensor
Mass or volume air flow circuitMass air flow sensor circuit
Vacuum sensorManifold air pressure sensor
Internal control module, Control module, Engine control
ECU, PCMPower train control module
FC idleDeceleration fuel cut
Idle air control valveIdle speed control
VSV for CCV, Canister close valve VSV for canister controlEvaporative emissions canister vent valve
VSV for EVAP, Vacuum switching valve assembly No. 1,
EVAP VAV, Purge VSVEvaporative emissions canister purge valve
VSV for pressure switching valve, Bypass VSVEvaporative emission pressure switching valve
Vapor pressure sensor, EVAP pressure sensor, Evaporative
emission control system pressure sensorFuel tank pressure sensor
Charcoal canisterEvaporative emissions canister
ORVR systemOn±board refueling vapor recovery system
Intake manifold runner controlIntake manifold tuning system
Intake manifold runner valve, IMRV, IACV (runner valve)Intake manifold tuning valve
Intake control VSVIntake manifold tuning solenoid valve
AFSAir fuel ratio sensor
O2 sensorHeater oxygen sensor
Oxygen sensor pumping current circuitOxygen sensor output signal
Oxygen sensor reference ground circuitOxygen sensor signal ground
Accel position sensorAccelerator pedal position sensor
Throttle actuator control motor, Actuator control motor, Elec-
tronic throttle motor, Throttle control motorElectronic throttle actuator
Electronic throttle control system, Throttle actuator control
systemElectronic throttle control system
Throttle/pedal position sensor, Throttle/pedal position switch,
Throttle position sensor/switchThrottle position sensor
Turbo press sensorTurbocharger pressure sensor
Turbo VSVTurbocharger pressure control solenoid valve
P/S pressure switchPower±steering pressure switch
VSV for ACMActive control engine mount
Speed sensor, Vehicle speed sensor ºAº, Speed sensor for
skid control ECUVehicle speed sensor
ATF temperature sensor, Trans. fluid temp. sensor, ATF
temperature sensor ºAºTransmission fluid temperature sensor
Electronic controlled automatic transmission, ECTElectronically controlled automatic
Intermediate shaft speed sensor ºAºCounter gear speed sensor