air condition TOYOTA SIENNA 2007 Service Manual PDF

ES–1102GR-FE ENGINE CONTROL SYSTEM – SFI SYSTEM
ES
HINT:
• Bank 1 refers to the bank that includes cylinder No. 1.
• Bank 2 refers to the bank that does not include cylinder No. 1.
• Sensor 1 refers to the closest sensor to the engine assembly.
• Sensor 2 refers to the furthest sensor away from the engine assembly.
MONITOR DESCRIPTION
The ECM uses information from the Air-Fuel Ratio (A/F) sensor to regulate the air-fuel ratio and keep it
close to the stoichiometric level. This maximizes the ability of the Three-Way Catalytic Converter (TWC) to
purify the exhaust gas.
The A/F sensor detects oxygen levels in the exhaust gas and transmits the information to the ECM. The
inner surface of the sensor element is exposed to the outside air. The outer surface of the sensor element
is exposed to the exhaust gas. The sensor element is made of platinum coated zirconia and includes an
integrated heating element.
The zirconia element generates small voltage when there is a large difference in the oxygen
concentrations between the exhaust gas and outside air. The platinum coating amplifies this voltage
generation.
The A/F sensor is more efficient when heated. When the exhaust gas temperature is low, the sensor
cannot generate useful voltage signals without supplementary heating. The ECM regulates the
supplementary heating using a duty-cycle approach to adjust the average current in the sensor heater
element. If the heater current is outside the normal range, the signal transmitted by the A/F sensor will be
inaccurate, as a result, the ECM will be unable to regulate air-fuel ratio properly.
When the current in the A/F sensor heater is outside the normal operating range, the ECM interprets this
as a malfunction in the sensor heater and sets a DTC.
Example:
The ECM sets DTC P0032 or P0052 when the current in the A/F sensor heater is more than 10 A.
Conversely, when the heater current is less than 0.8 A, DTC P0031 or P0051 is set.
MONITOR STRATEGY
TYPICAL ENABLING CONDITIONS
All:
P0031 and P0051:
P0032
P0052Air-Fuel Ratio (A/F) sensor heater current more than 10
A (1 trip detection logic)• Short in A/F sensor heater circuit
• A/F sensor heater
• A/F sensor heater relay
•ECM
Related DTCsP0031: A/F sensor heater (Bank 1) range check (Low current)
P0032: A/F sensor heater (Bank 1) range check (High current)
P0051: A/F sensor heater (Bank 2) range check (Low current)
P0052: A/F sensor heater (Bank 2) range check (High current)
Required sensors / components (Main) A/F sensor heater
Required sensors / components (Related) -
Frequency of operation Continuous
Duration 10 seconds
MIL operation Immediate
Sequence operation None
The monitor will run whenever these DTCs are not
presentNone
Battery voltage 10.5 V or more
Heater ON duty ratio 50% or moreDTC No. DTC Detection Condition Trouble Area

2GR-FE ENGINE CONTROL SYSTEM – SFI SYSTEMES–111
ES
P0032 and P0052:
TYPICAL MALFUNCTION THRESHOLDS
P0031 and P0051:
P0032 and P0052:
COMPONENT OPERATING RANGE
MONITOR RESULT
Refer to CHECKING MONITOR STATUS (See page ES-19).
WIRING DIAGRAM
Refer to DTC P2195 (See page ES-359).
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.
Time after engine starts 10 seconds or more
Time after engine starts 10 seconds or more
Heater current Less than 0.8 A
Hybrid IC high current limit port Fail
A/F sensor heater current 0.8 A or more

ES–1122GR-FE ENGINE CONTROL SYSTEM – SFI SYSTEM
ES
(a) Disconnect the A5 or A6 A/F sensor connector.
(b) Measure the resistance according to the value(s) in the
table below.
Standard resistance:
Bank 1
Bank 2
(c) Reconnect the A/F sensor connector.
Result
B
C
A
(a) Disconnect the A5 or A6 A/F sensor 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 A/F sensor connector.
OK
NG
1INSPECT AIR FUEL RATIO SENSOR (HEATER RESISTANCE)
A126269E35
Tester Connection Condition Specified Condition
HT (1) - +B (2) 20
C (68F) 1.8 to 3.4
HT (1) - AF- (4) Always 10 k or higher
Tester Connection Condition Specified Condition
HT (1) - +B (2) 20
C (68F) 1.8 to 3.4
HT (1) - AF- (4) Always 10 k or higher
Result Proceed to
OK A
NG (for 2WD model) B
NG (for 4WD model) C
REPLACE AIR FUEL RATIO SENSOR (See
page EC-19)
REPLACE AIR FUEL RATIO SENSOR (See
page EC-26)
2CHECK TERMINAL VOLTAGE (+B OF A/F SENSOR)
A076787E21
Tester Connection Specified Condition
+B (A5-2) - Body ground 9 to 14 V
+B (A6-2) - Body ground 9 to 14 V
Go to step 7

ES–1142GR-FE ENGINE CONTROL SYSTEM – SFI SYSTEM
ES
(a) Disconnect the A5 or A6 A/F sensor connector.
(b) Remove the A/F relay from the No. 6 engine room relay
block.
(c) Measure the resistance according to the value(s) in the
table below.
Standard resistance:
Check for open
Check for short
(d) Reinstall the A/F relay.
(e) Reconnect the A/F sensor connector.
NG
OK
(a) Remove the A/F relay from the No. 6 engine room relay
block.
(b) Measure the resistance according to the value(s) in the
table below.
Standard resistance:
Check for open
NG
5CHECK HARNESS AND CONNECTOR (A/F SENSOR - A/F RELAY)
A165502E01
Tester Connection Specified Condition
A/F relay terminal (3) - +B (A5-2) Below 1
A/F relay terminal (3) - +B (A6-2) Below 1
Tester Connection Specified Condition
A/F relay terminal (3) - +B (A5-2) - Body ground 10 k
or higher
A/F relay terminal (3) - +B (A6-2) - Body ground 10 k
or higher
REPAIR OR REPLACE HARNESS OR
CONNECTOR (A/F SENSOR - A/F RELAY)
6CHECK HARNESS AND CONNECTOR (A/F RELAY - BODY GROUND)
A165503E02
Tester Connection Specified Condition
A/F relay terminal (2) - Body ground Below 1
REPAIR OR REPLACE HARNESS OR
CONNECTOR (A/F RELAY - BODY GROUND)

2GR-FE ENGINE CONTROL SYSTEM – SFI SYSTEMES–115
ES
OK
(a) Disconnect the A5 or A6 A/F sensor connector.
(b) Disconnect the E10 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 ECM connector.
(e) Reconnect the A/F sensor connectors.
NG
OK
(a) Connect the intelligent tester to the DLC3.
(b) Turn the ignition switch to the ON position.
(c) Turn the intelligent tester ON.
(d) Clear the DTCs (See page ES-39).
(e) Start the engine.
(f) Allow the engine to idle for 1 minute or more.
(g) Select the following menu items: DIAGNOSIS /
ENHANCED OBD II / DTC INFO / CURRENT CODES.
(h) Read the DTCs.
Result
B REPAIR OR REPLACE HARNESS OR CONNECTOR (A/F RELAY - BATTERY)
7CHECK HARNESS AND CONNECTOR (A/F RELAY - ECM)
A085836E04
Tester Connection Specified Condition
HT (A5-1) - HA1A (E10-2) Below 1
HT (A6-1) - HA2A (E10-1) Below 1
Tester Connection Specified Condition
HT (A5-1) or HA1A (E10-2) - Body ground 10 k
or higher
HT (A6-1) or HA2A (E10-1) - Body ground 10 k
or higher
REPAIR OR REPLACE HARNESS OR
CONNECTOR (A/F RELAY - ECM)
8CHECK WHETHER DTC OUTPUT RECURS
Display (DTC Output) Proceed to
No output A
P0031, P0032, P0051 and/or P0052 B
REPLACE ECM (See page ES-498)

ES–1202GR-FE ENGINE CONTROL SYSTEM – SFI SYSTEM
ES
• 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) Disconnect the H14 heated oxygen (HO2) sensor
connector (Bank 1 Sensor 2) or H9 heated oxygen
sensor connector (Bank 2 Sensor 2).
(b) Measure the resistance according to the value(s) in the
table below.
Standard resistance:
Bank 1
Bank 2
(c) Reconnect the HO2 sensor connectors.
NG
OK
1INSPECT HEATED OXYGEN SENSOR (HEATER RESISTANCE)
A112643E03
Tester Connection Condition Specified Condition
HT (1) - +B (2) 20
C (68F) 11 to 16
HT (1) - E1 (4) Always 10 k or higher
Tester Connection Condition Specified Condition
HT (1) - +B (2) 20
C (68F) 11 to 16
HT (1) - E1 (4) Always 10 k or higher
REPLACE HEATED OXYGEN SENSOR

ES–1222GR-FE ENGINE CONTROL SYSTEM – SFI SYSTEM
ES
(a) Remove the EFI relay from the engine room junction
block.
(b) Measure the resistance according to the value(s) in the
table below.
Standard resistance
(c) Reinstall the EFI relay.
NG
OK
(a) Disconnect the H14 or H9 HO2 sensor connector.
(b) Disconnect the E9 and E10 ECM connectors.
(c) Measure the resistance according to the value(s) in the
table below.
Standard resistance:
Check for open
Check for short
(d) Reconnect the ECM connectors.
(e) Reconnect the HO2 sensor connectors.
NG
4INSPECT RELAY (EFI RELAY)
B016200
Tester Connection Specified Condition
3 - 5 10 k
or higher
3 - 5Below 1
(Apply battery voltage between terminals 1 and 2)
REPLACE RELAY (EFI RELAY)
REPAIR OR REPLACE HARNESS OR CONNECTOR (HO2 SENSOR - EFI RELAY)
5CHECK HARNESS AND CONNECTOR (HO2 SENSOR - ECM)
A163309E01
Tester Connection Specified Condition
HT (H14-1) - HT1B (E9-1) Below 1
OX (H14-3) - OX1B (E9-18) Below 1
HT (H9-1) - HT2B (E10-5) Below 1
OX (H9-3) - OX2B (E10-33) Below 1
Tester Connection Specified Condition
HT (H14-1) or HT1B (E9-1) - Body ground 10 k
or higher
OX (H14-3) or OX1B (E9-18) - Body ground 10 k
or higher
HT (H9-1) or HT2B (E10-5) - Body ground 10 k
or higher
OX (H9-3) or OX2B (E10-33) - Body ground 10 k
or higher
REPAIR OR REPLACE HARNESS OR
CONNECTOR (HO2 SENSOR - ECM)

ES–1242GR-FE ENGINE CONTROL SYSTEM – SFI SYSTEM
ES
DESCRIPTION
The Mass Air Flow (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 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 in 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.
The circuit is constructed so that the platinum hot wire and the temperature sensor provide a bridge
circuit, and the power transistor is controlled so that the potentials of A and B remain equal to maintain the
predetermined temperature.
HINT:
When any of these DTCs are set, the ECM enters fail-safe mode. During fail-safe mode, the ignition
timing is calculated by the ECM, according to the engine RPM and throttle valve position. Fail-safe mode
continues until a pass condition is detected.
HINT:
When any of these DTCs are set, check the air-flow rate by selecting the following menu items on an
intelligent tester: DIAGNOSIS / ENHANCED OBD II / DATA LIST / PRIMARY / MAF.
DTC P0100 Mass or Volume Air Flow Circuit
DTC P0102 Mass or Volume Air Flow Circuit Low Input
DTC P0103 Mass or Volume Air Flow Circuit High Input
DTC No. DTC Detection Condition Trouble Area
P0100Open or short in Mass Air Flow (MAF) meter circuit for 3
seconds• Open or short in MAF meter circuit
• MAF meter
•ECM
P0102Open in Mass Air Flow (MAF) meter circuit for 3
seconds• Open in MAF meter circuit
• Short in ground circuit
• MAF meter
•ECM
P0103Short in Mass Air Flow (MAF) meter circuit for 3
seconds• Short in MAF meter circuit (+B circuit)
• MAF meter
•ECM
A140749E02

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