2001 TOYOTA SEQUOIA Page 18

B17443
Wire Harness Side:
Air Injection Driver Connector
A40
B17438
Wire Harness Side:
Air Pump Connector
A43
± DIAGNOSTICSENGINE
DI±441
635 Author: Date:
2005 SEQUOIA (RM1146U)
14 Check for open and short in harness and connector between air injection driver
and air pump.
PREPARATION:
(a) Remove the intake manifold (see page EM±36).
(b) Disconnect the A40 air injection driver connector.
(c) Disconnect the A43 air pump connector.
CHECK:
Measure the resistance between the wire harness side connec-
tors.
OK:
Standard:
Tester ConnectionSpecified Condition
VP (A40±2) ± A43±2Below 1 W
VP (A40±2) or A43±2 ±
Body ground10 kW or higher
NG Repair or replace harness or connector.
OK
Replace air injection driver.

± 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±445
639 Author: Date:
2005 SEQUOIA (RM1146U)
DTC P043E Evaporate Emission System Reference Ori-
fice Clog Up
DTC P043F Evaporate Emission System Reference Ori-
fice High Flow
DTC SUMMARY
DTCsMonitoring ItemsMalfunction Detection ConditionsTrouble AreasDetection
TimingsDetection
Logic
P043E0.02 inch orifice clogged
Vacuum pump creates negative pressure
through 0.02 inch orifice, and EVAP system
pressure is measured to determine leak
pressure standard. 0.02 inch leak pressure
standard is measured at the start and at the
end of the leak check.
If system pressure lower than ±4.85 kPa
(±36.38 mmHg)*, ECM determines that
0.02 inch orifice has clogging malfunction.

Pump module

Connector/Wire harness
(Pump module ± ECM)

ECM

Leakage from EVAP sys-
tem
While
ignition
switch is
OFF
2 trip
P043F0.02 inch orifice high±flow
Vacuum pump creates negative pressure
through 0.02 inch orifice, and EVAP system
pressure is measured to determine leak
pressure standard. 0.02 inch leak pressure
standard is measured at the start and at the
end of the leak check.
If system pressure higher than ±1.06 kPa
(±7.95 mmHg)*, ECM determines that 0.02
inch orifice has high±flow malfunction.

Pump module

Connector/Wire harness
(Pump module ± ECM)

ECM

Leakage from EVAP sys-
tem
While
ignition
switch is
OFF
2 trip
*: The threshold values vary according to the atmospheric pressure measured at EVAP monitor beginning.
The values described in the table above are based on an atmospheric pressure of 100 kPa (750.1 mmHg)
(absolute pressure).
HINT:
The 0.02 inch orifice is located inside the pump module.
CIRCUIT DESCRIPTION
The circuit description can be found in the EVAP (Evaporative Emission) Inspection Procedure (see page
DI±460).
DID8I±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±

DI±450
± DIAGNOSTICSENGINE
644 Author: Date:
2005 SEQUOIA (RM1146U) Next sequence is run if both of following
conditions set
Condition 1 and 2
1. Vacuum introduction time±15 min.
2. FTPFTP was saturated
5. Purge VSV stuck closed check±
Next sequence is run if following condition
set±
FTP change for 10 sec. after purge VSV
ON (open)2.25 mmHg (0.3 kPa)±
6. Second reference pressure measure-
ment±
Next sequence is run if all of following
conditions setCondition 1, 2, 3 and 4
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
4. Reference pressure difference between
first and second±5.25 mmHg (0.7 kPa)
7. Leak check±
Next sequence is run if following condition
set±
FTP when vacuum introduction was com-
plete±Second reference pressure
8. Atmospheric pressure±
Monitor is complete if following±
Atmospheric pressure difference between
sequence 1 and 8±2.25 mmHg (0.3 kPa)
TYPICAL MALFUNCTION THRESHOLDS
Detection CriteriaThreshold
Following values are when atmospheric pressure is 760
mmHg (100 kPa)±
One of the following conditions is met±
FTP when 4 sec. after reference pressure measurement
beganMore than ±7.5 mmHg (±1 kPa)
Reference pressureLess than ±36.38 mmHg (±4.85 kPa)
Reference pressure±7.93 mmHg (±1.057 kPa) or more
Reference pressureNot saturated
Reference pressure difference between first and second5.3 mmHg (0.7 kPa) or more
MONITOR RESULT (MODE 06 DATA)
Refer to page DI±26 for detailed information on Monitor Result.
INSPECTION PROCEDURE
Refer to the EVAP Inspection Procedure (see page DI±460).

A23458
Air±fuel Ratio Sensor Output:
Active A/F Control
A/F Sensor Output
Fuel Injection VolumeON
OFF
NormalMalfunction 10 Seconds
± DIAGNOSTICSENGINE
DI±451
645 Author: Date:
2005 SEQUOIA (RM1146U)
DTC P2A00 A/F Sensor Circuit Slow Response (Bank 1
Sensor 1)
DTC P2A03 A/F Sensor Circuit Slow Response (Bank 2
Sensor 1)
CIRCUIT DESCRIPTION
Refer to DTC P2195 on page DI±383.
DTC No.DTC Detection ConditionsTrouble Areas
P2A00
P2A03Calculated test value for A/F sensor response rate deteriora-
tion level is less than threshold.
Open or short in A/F sensor (sensor 1) circuit

A/F sensor (sensor 1)

ECM
MONITOR DESCRIPTION
After engine is warmed up, the ECM performs air±fuel ratio feedback control to regulate the air±fuel ratio
at stoichiometric ratio. In addition, this vehicle performs Active A/F Ratio Control for approximately 10 se-
conds after preconditions met in order to measure the A/F sensor response rate. During active air±fuel ratio
control, the ECM forcibly increases and decreases the injection volume for certain amount based on learned
stoichiomentric air ±fuel ratio during usual air±fuel feedback control, and measures the A/F sensor response
rate. The ECM calculates the signal from the A/F sensor while value for A/F sensor response rate deteriora-
tion level.
If the test value for A/F sensor response rate deterioration level is less than threshold, ECM interprets this
as a malfunction, and sets the DTC.
DIDFY±01

± 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.