2001 TOYOTA SEQUOIA OBD 2

± DIAGNOSTICSENGINE
DI±81
275 Author: Date:
2005 SEQUOIA (RM1146U)
1 Check operation of OCV.
PREPARATION:
(a) Connect the hand±held tester to the DLC3.
(b) Start the engine and warm it up.
(c) Turn the ignition switch to ON and turn the hand±held tester ON.
CHECK:
(a) Select the item: DIAGNOSIS / ENHANCED OBD II / ACTIVE TEST / VVT CTRL B1 or VVT CTRL B2.
(b) Using the hand±held tester, operate the OCV and check the engine speed.
OK:
Standard:
Tester OperationSpecified Condition
OCV is OFFNormal engine speed
OCV is ONRough idle or engine stall
OK VVT system is OK.*
*: DTC P0011, P0012, P0021 or P0022 is also output when a
foreign object is detected in some parts of the system in the en-
gine oil, and then the system returns to normal in a short time.
As ECM is controlled to eject a foreign object, there is no prob-
lem on the VVT. There is also no problem on the VVT as the oil
filter should catch the foreign object in the engine oil.
NG
2 Check valve timing (See page EM±23).
NG Adjust valve timing.
OK

A02961
V5
VVT Sensor (Bank 1)ECM
1
2R
G
Y
LVVL+
VVL±
VVR+
E5 18
19
19
18
VVR±
1
2E5
E4
E4 V6
VVT Sensor (Bank 2)
± DIAGNOSTICSENGINE
DI±87
281 Author: Date:
2005 SEQUOIA (RM1146U)
WIRING DIAGRAM
INSPECTION PROCEDURE
HINT:

If DTC P0016 is displayed, check left bank VVT sensor.

If DTC P0018 is displayed, check right bank VVT sensor.

Read freeze frame data using hand±held tester or OBD II scan tool. Because freeze frame records
the engine conditions when the malfunction is detected. When troubleshooting, it is useful for deter-
mining whether the vehicle was running or stopped, the engine was warmed up or not, the air±fuel ratio
was lean or rich, etc. at the time of the malfunction.
1 Check valve timing (Check for loose and jumping teeth of timing belt) (See page
EM±16).
NG Adjust valve timing (Repair or replace timing
belt).
OK
Replace ECM (See page SF±80).

B17396
HT +B
AF± AF+ Sensor 1A/F Sensor Component Side:
Front View
DI±90
± DIAGNOSTICSENGINE
284 Author: Date:
2005 SEQUOIA (RM1146U) P0032, P0052 (High current):
Time after engine start10 sec.±
TYPICAL MALFUNCTION THRESHOLDS
Detection CriteriaThreshold
P0031, P0051 (Low current):
A/F sensor heater currentLess than 0.8 A
P0032, P0052 (High current):
A/F sensor heater currentMore than 10 A
COMPONENT OPERATING RANGE
ParameterStandard Value
A/F sensor heater current1.8 to 3.4 A at 20°C (68°F)
WIRING DIAGRAM
Refer to DTC P2195 on page DI±383.
INSPECTION PROCEDURE
HINT:
Read freeze frame data using a hand±held tester or OBD II scan tool. 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 Check resistance of air±fuel ratio (A/F) sensor heater.
PREPARATION:
Disconnect the air±fuel ratio (A/F) sensor connector.
CHECK:
Measure resistance between the terminals of the A/F sensor
connector.
OK:
Standard:
Tester ConnectionSpecified Condition
HT (1) ± +B (2)1.8 W to 3.4 W at 20C (68F)
HT (1) ± AF± (4)10 kW or higher
NG Replace air±fuel ratio (A/F) sensor.
OK

± DIAGNOSTICSENGINE
DI±103
297 Author: Date:
2005 SEQUOIA (RM1146U)
HINT:
After confirming DTC P0100, P0102 or P0103, use the hand±held tester or the OBD II scan tool to confirm
the MAF ratio from the ALL menu (to reach the ALL menu: DIAGNOSIS / ENHANCED OBD II / DATA LIST
/ ALL).
Mass Air Flow Value (gm/sec.)Malfunction
Approx. 0.0
Mass air flow meter power source circuit open

VG circuit open or short
271.0 or more
EVG circuit open
MONITOR DESCRIPTION
If there is a defect in the MAF (Mass Air Flow) meter or an open or short circuit, the voltage level will deviate
outside the normal operating range. The ECM interprets this deviation as a defect in the MAF meter and sets
a DTC.
Example:
When the MAF meter voltage output is less than 0.2 V, or more than 4.9 V, and if either the condition contin-
ues for more than 3 sec.
MONITOR STRATEGY
P0100Mass air flow meter circuit range check
(Fluttering)
Related DTCsP0102Mass air flow meter circuit range check
(Low voltage)
P0103Mass air flow meter circuit range check
(High voltage)
Required sensors/componentsMass air flow meter
Frequency of operationContinuous
Duration3 sec.
MIL operationImmediate (When engine speed is at less than 4,000 rpm)
2 driving cycles (When engine speed is at 4,000 rpm or more)
Sequence of operationNone
TYPICAL ENABLING CONDITIONS
The monitor will run whenever these
DTCs are not presentSee page DI±18
The typical enabling condition is not avail-
able±
TYPICAL MALFUNCTION THRESHOLDS
Detection CriteriaThreshold
P0100:
Mass air flow meter voltageLess than 0.2 V, or more than 4.9 V
P0102:
Mass air flow meter voltageLess than 0.2 V
P0103:
Mass air flow meter voltageMore than 4.9 V

± 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±112
± DIAGNOSTICSENGINE
306 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 Are there any other codes (besides DTC P0101) 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 DTC using the hand±held tester.
RESULT:
Display (DTC output)Proceed to
ºP0101º and other DTCsA
Only P0101B
HINT:
If any other codes besides P0101 are output, perform the troubleshooting for those codes first.
B Replace mass air flow meter.
A
Go to relevant DTC chart (See page DI±58).

± 20 0 20 40 60 80 100
(± 4) 32 68 104 140 176 212 30
20
10
5
3
2
1
0.5
0.3
0.2
0.1
A21047
Acceptable (Fig.1)
Resistance KW
Temp. C (F)
± DIAGNOSTICSENGINE
DI±113
307 Author: Date:
2005 SEQUOIA (RM1146U)
DTC P0110 Intake Air Temperature Circuit
DTC P0112 Intake Air Temperature Circuit Low Input
DTC P0113 Intake Air Temperature Circuit High Input
CIRCUIT DESCRIPTION
The intake air temperature (IAT) sensor, mounted on the mass
air flow (MAF) meter, monitors the intake air temperature. The
IAT sensor has a thermistor that varies its resistance depending
on the temperature of the intake air. When the air temperature
is low, the resistance in the thermistor increases. When the tem-
perature is high, the resistance drops. The resistance varies as
voltage changes to the ECM terminal.
(See Fig. 1).
The intake air temperature sensor is connected to the ECM
(See below ). The 5 V power source voltage in the ECM is ap-
plied to the intake air temperature sensor from terminal THA
(THAR) via resistor R.
That is, the resistor R and the intake air temperature sensor are
connected in series. When the resistance value of the intake air
temperature sensor changes in accordance with changes in the
intake air temperature, the voltage at terminal THA (THAR) also
changes. Based on this signal, the ECM increases the fuel in-
jection volume to improve the driveability during cold engine op-
eration.
DTC No.Proceed toDTC Detection ConditionTrouble Area
P0110Step 1
Open or short in intake air
temperature sensor circuit for
0.5 sec.

Open or short in intake air temperature sensor circuit
P0112Step 4Short in intake air tempera-
ture sensor circuit for 0.5 sec.

Open or short in intake air temperature sensor circuit

Intake air temperature sensor (built in mass air flow meter)

ECM
P0113Step 2Open in intake air tempera-
ture sensor circuit for 0.5 sec.
ECM
HINT:
After confirming DTC ºP0110, P0112 or P0113º, use the hand±held tester to confirm the intake air tempera-
ture in the ºDIAGNOSIS / ENHANCED OBD II / DATA LIST / ALLº.
Temperature DisplayedMalfunction
±40°C (±40°F)Open circuit
140°C (284°F) or moreShort circuit
DI3HN±13

DI±116
± DIAGNOSTICSENGINE
310 Author: Date:
2005 SEQUOIA (RM1146U)
1 Connect hand±held tester, and read value of intake air temperature.
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 / DATA
LIST / ALL / INTAKE AIR.
CHECK:
Read the temperature value on the hand±held tester.
OK:
Same as actual intake air temperature.
RESULT:
Displayed TemperatureProceed to
±40°C (±40°F)A
140°C (284°F) or moreB
OK (Same as present temperature)C
HINT:

If there is an open circuit, the hand±held tester indicates ±40°C (±40°F).

If there is a short circuit, the hand±held tester indicates 140°C (284°F) or more.
B Go to step 4.
C Check for intermittent problems
(See page DI±11).
A