TOYOTA SIENNA 2007 Service Repair Manual

2GR-FE ENGINE CONTROL SYSTEM – SFI SYSTEMES–125
ES
MONITOR DESCRIPTION
If there is a defect in the MAF meter or an open or short circuit, the voltage level deviates from the normal
operating range. The ECM interprets this deviation as a malfunction in the MAF meter and sets a DTC.
Example:
When the sensor voltage output remains less than 0.2 V, or more than 4.9 V, for more than 3 seconds, the
ECM sets a DTC.
If the malfunction is not repaired successfully, a DTC is set 3 seconds after the engine is next started.
MONITOR STRATEGY
TYPICAL ENABLING CONDITIONS
TYPICAL MALFUNCTION THRESHOLDS
P0100:
P0102:
P0103:
COMPONENT OPERATING RANGE
Mass Air Flow Rate (gm/s) Malfunctions
Approximately 0.0• Open in Mass Air Flow (MAF) meter power source circuit
• Open or short in VG circuit
271.0 or more Open in E2G circuit
Related DTCsP0100: Mass air flow meter range check (Fluctuating)
P0102: Mass air flow meter range check (Low voltage)
P0103: Mass air flow meter range check (High voltage)
Required Sensors / Components (Main) MAF meter
Required Sensors / Components (Related) Crankshaft position sensor
Frequency of Operation Continuous
Duration 3 seconds
MIL OperationImmediate: Engine RPM less than 4000 rpm
2 driving cycles: Engine RPM 4000 rpm or more
Sequence of Operation None
The monitor will run whenever these DTCs are not
presentNone
Mass air flow meter voltage Less than 0.2 V, or more than 4.9 V
Mass air flow meter voltage Less than 0.2 V
Mass air flow meter voltage More than 4.9 V
Mass air flow meter voltage Between 0.4 V and 2.2 V

ES–1262GR-FE ENGINE CONTROL SYSTEM – SFI SYSTEM
ES
WIRING DIAGRAM
INSPECTION PROCEDURE
HINT:
Read freeze frame data using the intelligent tester. The ECM records vehicle and driving condition
information as freeze frame data the moment a DTC is stored. When troubleshooting, freeze frame data
can be helpful in determining whether the vehicle was running or stopped, whether the engine was
warmed up or not, whether the air-fuel ratio was lean or rich, as well as other data recorded at the time of
a malfunction.
(a) Connect the intelligent tester to the DLC3.
(b) Start the engine.
(c) Turn the tester on.
(d) Select the following menu items: DIAGNOSIS /
ENHANCED OBD II / DATA LIST / PRIMARY / MAF.
(e) Read the values displayed on the tester.
1READ VALUE OF INTELLIGENT TESTER (MASS AIR FLOW RATE)
A117876E09

2GR-FE ENGINE CONTROL SYSTEM – SFI SYSTEMES–127
ES
Result
*1: The value must be changed when the throttle valve is
open or closed.
B
C
A
(a) Disconnect the M6 Mass Air Flow (MAF) meter
connector.
(b) Turn the ignition switch to the ON position.
(c) Measure the voltage according to the value(s) in the
table below.
Standard voltage
(d) Reconnect the MAF meter connector.
NG
OK
(a) Start the engine.
(b) Measure the voltage between the terminals of the E9
ECM connector.
HINT:
The transmission gear selector lever should be in the P
or N position and the A/C switch should be turned off.
Standard voltage
OK
NG
Mass Air Flow Rate (gm/s) Proceed to
0.0 A
271.0 or more B
Between 1.0 and 270.0 (*1) C
Go to step 6
CHECK FOR INTERMITTENT PROBLEMS
2INSPECT MASS AIR FLOW METER (POWER SOURCE VOLTAGE)
A127724E33
Tester Connection Specified Condition
+B (M6-3) - Body ground 9 to 14 V
Go to step 5
3INSPECT ECM (VG VOLTAGE)
A162489E01
Tester Connection Condition Specified Condition
VG (E9-30) - E2G (E9-
29)Engine idling 0.5 to 3.0 V
REPLACE ECM (See page ES-498)

ES–1282GR-FE ENGINE CONTROL SYSTEM – SFI SYSTEM
ES
(a) Disconnect the M6 MAF meter connector.
(b) Disconnect the E9 ECM connector.
(c) Measure the resistance according to the value(s) in the
table below.
Standard resistance :
Check for open
Check for short
(d) Reconnect the MAF meter connector.
(e) Reconnect the ECM connector.
NG
OK
(a) Remove the EFI No. 2 fuse from the engine room relay
block.
(b) Measure the resistance according to the value(s) in the
table below.
Standard resistance:
Below 1
(c) Reinstall the EFI No. 2 fuse.
NG
OK
4CHECK HARNESS AND CONNECTOR (MASS AIR FLOW METER - ECM)
A140709E07
Tester Connection Specified Condition
VG (M6-5) - VG (E9-30) Below 1
E2G (M6-4) - E2G (E9-29) Below 1
Tester Connection Specified Condition
VG (M6-5) or VG (E9-30) - Body ground 10 k
or higher
E2G (M6-4) or E2G (E9-29) - Body ground 10 k
or higher
REPAIR OR REPLACE HARNESS OR
CONNECTOR (MASS AIR FLOW METER -
ECM)
REPLACE MASS AIR FLOW METER (See page ES-504)
5INSPECT FUSE (EFI NO. 2 FUSE)
A162360E09
REPLACE EFI NO. 2 FUSE
REPAIR OR REPLACE HARNESS OR CONNECTOR (MASS AIR FLOW METER - EFI RELAY)

2GR-FE ENGINE CONTROL SYSTEM – SFI SYSTEMES–129
ES
(a) Measure the resistance according to the value(s) in the
table below.
Standard resistance
NG
OK
(a) Disconnect the M6 MAF meter connector.
(b) Disconnect the E9 ECM connector.
(c) Measure the resistance according to the value(s) in the
table below.
Standard resistance:
Check for open
Check for short
(d) Reconnect the MAF meter connector.
(e) Reconnect the ECM connector.
NG
OK
6INSPECT ECM (SENSOR GROUND)
A162489E02
Tester Connection Specified Condition
E2G (E9-29) - Body ground Below 1
REPLACE ECM (See page ES-498)
7CHECK HARNESS AND CONNECTOR (MASS AIR FLOW METER - ECM)
A140709E07
Tester Connection Specified Condition
VG (M6-5) - VG (E9-30) Below 1
E2G (M6-4) - E2G (E9-29) Below 1
Tester Connection Specified Condition
VG (M6-5) or VG (E9-30) - Body ground 10 k
or higher
E2G (M6-4) or E2G (E9-29) - Body ground 10 k
or higher
REPAIR OR REPLACE HARNESS OR
CONNECTOR (MASS AIR FLOW METER -
ECM)
REPLACE MASS AIR FLOW METER (See page ES-504)

ES–1302GR-FE ENGINE CONTROL SYSTEM – SFI SYSTEM
ES
DESCRIPTION
Refer to DTC P0100 (See page ES-116).
MONITOR DESCRIPTION
The MAF meter is a sensor that measures the amount of air flowing through the throttle valve. The ECM
uses this information to determine the fuel injection time and to provide an appropriate air-fuel ratio.
Inside the MAF meter, there is a heated platinum wire which is exposed to the flow of intake air. By
applying a specific electrical current to the wire, the ECM heats it to a specific temperature. The flow of
incoming air cools both the wire and an internal thermistor, changing their resistance. To maintain a
constant current value, the ECM varies the voltage applied to these components of the MAF meter. The
voltage level is proportional to the air flow through the sensor, and the ECM uses it to calculate the intake
air volume.
If there is a defect in the sensor, or an open or short in the circuit, the voltage level deviates from the
normal operating range. The ECM interprets this deviation as a malfunction in the MAF meter and sets the
DTC.
Example:
If the voltage is more than 2.2 V, or less than 0.73 V while idling, the ECM determines that there is a
malfunction in the MAF meter and sets the DTC.
MONITOR STRATEGY
TYPICAL ENABLING CONDITIONS
DTC P0101Mass or Volume Air Flow Circuit Range / Perfor-
mance Problem
DTC No. DTC Detection Condition Trouble Area
P01011. High voltage:
Conditions (a), (b) and (c) continue for more than
10 seconds (2 trip detection logic):
(a) Engine speed is less than 2000 rpm
(b) Engine coolant temperature is 70
C (158F) or
higher
(c) Voltage output of Mass Air Flow (MAF) meter is
more than 1.24 V (varies with Throttle Position [TP]
sensor voltage)
2. Low voltage:
Conditions (a) and (b) continue for more than 10
seconds (2 trip detection logic):
(a) Engine speed is more than 300 rpm
(b) Voltage output of MAF meter is less than 0.80 V
(varies with TP sensor voltage)MAF meter
Related DTCs P0101: Mass air flow meter rationality
Required Sensors / Components (Main) Mass air flow meter
Required Sensors / Components (Related)Crankshaft position sensor, engine coolant temperature sensor and throttle position
sensor
Frequency of Operation Continuous
Duration 10 times
MIL Operation 2 driving cycles
Sequence of Operation None
The monitor will run whenever these DTCs are not
presentP0115, P0116, P0117, P0118 (ECT Sensor), P0120, P0121, P0122, P0123, P0220,
P0222, P0223, P2135 (TP Sensor), P0125 (Insufficient ECT for Closed Loop),
P0335 (CKP Sensor), P0340 (CMP Sensor)
Throttle position (TP sensor voltage) 0.24 V or more

2GR-FE ENGINE CONTROL SYSTEM – SFI SYSTEMES–131
ESTYPICAL MALFUNCTION THRESHOLDS
WIRING DIAGRAM
Refer to DTC P0100 (See page ES-118).
INSPECTION PROCEDURE
HINT:
Read freeze frame data using the intelligent tester. The ECM records vehicle and driving condition
information as freeze frame data the moment a DTC is stored. When troubleshooting, freeze frame data
can be helpful in determining whether the vehicle was running or stopped, whether the engine was
warmed up or not, whether the air-fuel ratio was lean or rich, as well as other data recorded at the time of
a malfunction.
(a) Connect the intelligent tester to the DLC3.
(b) Turn the ignition switch to the ON position.
(c) Turn the tester on.
(d) Select the following menu items: DIAGNOSIS /
ENHANCED OBD II / DTC INFO / CURRENT CODES.
(e) Read the DTCs.
Result
HINT:
If any DTCs other than P0101 are output, troubleshoot
those DTCs first.
B
A
Engine Running
Battery voltage 10.5 V or more
ECT 70
C (158F) or more
IAT sensor current OK
ECT sensor current OK
CKP sensor current OK
TP sensor current OK
FTP sensor OK
EVAP leak detection pump OK
EVAP vent valve OK
Averaged engine load Less than 0.80 %, or more than 1.24 %
1CHECK ANY OTHER DTCS OUTPUT (IN ADDITION TO DTC P0101)
Display (DTC Output) Proceed to
P0101 and other DTCs A
P0101 B
REPLACE MASS AIR FLOW METER (See
page ES-504)
GO TO DTC CHART (See page ES-56)

ES–1322GR-FE ENGINE CONTROL SYSTEM – SFI SYSTEM
ES
DESCRIPTION
The Intake Air Temperature (IAT) sensor, mounted on the Mass Air Flow (MAF) meter, monitors the IAT.
The IAT sensor has a built-in thermistor with a resistance that varies according to the temperature of the
intake air. When the IAT is low, the resistance of the thermistor increases. When the temperature is high,
the resistance drops. These variations in resistance are transmitted to the ECM as voltage changes (see
Fig. 1).
The IAT sensor is powered by a 5 V applied from the THA terminal of the ECM, via resistor R.
Resistor R and the IAT sensor are connected in series. When the resistance value of the IAT sensor
changes, according to changes in the IAT, the voltage at terminal THA also varies. Based on this signal,
the ECM increases the fuel injection volume when the engine is cold to improve driveability.
HINT:
When any of DTCs P0110, P0112 and P0113 are set, the ECM enters fail-safe mode. During fail-safe
mode, the IAT is estimated to be 20
C (68F) by the ECM. Fail-safe mode continues until a pass condition
is detected.
DTC P0110 Intake Air Temperature Circuit
DTC P0112 Intake Air Temperature Circuit Low Input
DTC P0113 Intake Air Temperature Circuit High Input
DTC No. Proceed to DTC Detection Condition Trouble Area
P0110 Step 1Open or short in Intake Air Temperature (IAT)
sensor circuit for 0.5 seconds (1 trip detection
logic)• Open or short in IAT sensor circuit
• IAT sensor (built into MAF meter)
•ECM
P0112 Step 4Short in Intake Air Temperature (IAT) sensor
circuit for 0.5 seconds (1 trip detection logic)• Short in IAT sensor circuit
• IAT sensor (built into MAF meter)
•ECM
P0113 Step 2Open in Intake Air Temperature (IAT) sensor
circuit for 0.5 seconds (1 trip detection logic)• Open in IAT sensor circuit
• IAT sensor (built into MAF meter)
•ECM
A056276E06

2GR-FE ENGINE CONTROL SYSTEM – SFI SYSTEMES–133
ES
HINT:
When any of these DTCs are set, check the IAT by selecting the following menu items on the intelligent
tester: DIAGNOSIS / ENHANCED OBD II / DATA LIST / PRIMARY / INTAKE AIR.
MONITOR DESCRIPTION
The ECM monitors the sensor voltage and uses this value to calculate the Intake Air Temperature (IAT).
When the sensor output voltage deviates from the normal operating range, the ECM interprets this as a
malfunction in the IAT sensor and sets a DTC.
Example:
If the sensor voltage output is -40
C (-40F) for 0.5 seconds or more, the ECM determines that there is an
open in the IAT sensor circuit, and sets DTC P0113. Conversely, if the voltage output is more than 140
C
(284
F) for 0.5 seconds or more, the ECM determines that there is a short in the sensor circuit, and sets
DTC P0112.
If the malfunction is not repaired successfully, a DTC is set 0.5 seconds after the engine is next started.
MONITOR STRATEGY
TYPICAL ENABLING CONDITIONS
TYPICAL MALFUNCTION THRESHOLDS
P0110:
P0112:
P0113:
COMPONENT OPERATING RANGE
Temperature Displayed Malfunctions
-40
C (-40F) Open circuit
140
C (284F) or higher Short circuit
Related DTCsP0110: Intake air temperature sensor open/short (Fluctuating)
P0112: Intake air temperature sensor short (Low electrical voltage)
P0113: Intake air temperature sensor open (High electrical voltage)
Required Sensors / Components (Main) Intake Air Temperature (IAT) sensor
Required sensors / Components (Related) -
Frequency of Operation Continuous
Duration 0.5 seconds
MIL Operation Immediate
Sequence of Operation None
The monitor will run whenever these DTCs are not
presentNone
Intake air temperature sensor voltage Less than 0.18 V or more than 4.91 V
Intake air temperature sensor voltage Less than 0.18 V [More than 140
C (284F)]
Intake air temperature sensor voltage More than 4.91 V [Less than -40
C (-40F)]
Intake air temperature sensor voltage 0.18 V to 4.91 V [-40 to 140
C (-40 to 284F)]

ES–1342GR-FE ENGINE CONTROL SYSTEM – SFI SYSTEM
ES
WIRING DIAGRAM
INSPECTION PROCEDURE
HINT:
• If other DTCs relating to different systems that have terminal E2 as the ground terminal are output
simultaneously, terminal E2 may have an open circuit.
• Read freeze frame data using the intelligent tester. The ECM records vehicle and driving condition
information as freeze frame data the moment a DTC is stored. When troubleshooting, freeze frame
data can be helpful in determining whether the vehicle was running or stopped, whether the engine
was warmed up or not, whether the air-fuel ratio was lean or rich, as well as other data recorded at the
time of a malfunction.
(a) Connect the intelligent tester to the DLC3.
(b) Turn the ignition switch to the ON position.
(c) Turn the tester on.
(d) Select the following menu items: DIAGNOSIS /
ENHANCED OBD II / DATA LIST / PRIMARY / INTAKE
AIR.
(e) Read the value displayed on the tester.
Standard:
Same as actual Intake Air Temperature (IAT).
Result
HINT:
• If there is an open circuit, the intelligent tester
indicates -40
C (-40F).
• If there is a short circuit, the intelligent tester indicates
140
C (284F) or higher.
B
1READ VALUE OF INTELLIGENT TESTER (INTAKE AIR TEMPERATURE)
A136106E05
Temperature Displayed Proceed to
-40
C (-40F) A
140
C (284F) or higher B
Same as actual IAT C
Go to step 4