TOYOTA SIENNA 2007 Service Repair Manual

ES–3782GR-FE ENGINE CONTROL SYSTEM – SFI SYSTEM
ES
NG
OK
(a) Replace the air fuel ratio sensor (for 2WD model (See
page EC-19) or 4WD model (See page EC-26)).
NEXT
NEXT
(a) Read the DTCs using the intelligent tester.
(b) Select the following menu items: DIAGNOSIS /
ENHANCED OBD II / DTC INFO / PENDING CODES.
Result
B
A
(a) Has the vehicle run out of fuel in the past?.
NO
YES
(a) Replace the air fuel ratio sensor (for 2WD model (See
page EC-19) or 4WD model (See page EC-26)).
NEXTREPLACE FUEL INJECTOR ASSEMBLY (See
page FU-13)
16REPLACE AIR FUEL RATIO SENSOR
17PERFORM CONFIRMATION DRIVING PATTERN
18CHECK WHETHER DTC OUTPUT RECURS (DTC P2195, P2196, P2197 OR P2198)
Display (DTC Output) Proceed to
No output A
P2195, P2196, P2197 or P2198 B
REPLACE ECM AND PERFORM
CONFIRMATION DRIVING PATTERN
19CONFIRM WHETHER VEHICLE HAS RUN OUT OF FUEL IN PAST
CHECK FOR INTERMITTENT PROBLEMS
DTC CAUSED BY RUNNING OUT OF FUEL
20REPLACE AIR FUEL RATIO SENSOR

2GR-FE ENGINE CONTROL SYSTEM – SFI SYSTEMES–379
ES
NEXT
(a) Connect the intelligent tester to the DLC3.
(b) Turn the ignition switch to the ON position and turn the
tester on.
(c) Read the DTCs using the intelligent tester.
(d) Select the following menu items: DIAGNOSIS /
ENHANCED OBD II / DTC INFO / PENDING CODES.
Result
B
A
21PERFORM CONFIRMATION DRIVING PATTERN
22CHECK WHETHER DTC OUTPUT RECURS (DTC P2195, P2196, P2197 OR P2198)
Display (DTC Output) Proceed to
No output A
P2195, P2196, P2197 or P2198 (A/F sensor pending DTCs) B
REPLACE ECM (See page ES-498)
END

ES–3802GR-FE ENGINE CONTROL SYSTEM – SFI SYSTEM
ES
HINT:
• Although the DTC titles say oxygen sensor, these DTCs relate to the Air-Fuel Ratio (A/F) sensor.
• Sensor 1 refers to the sensor mounted in front of the Three-Way Catalytic Converter (TWC) and
located near the engine assembly.
DESCRIPTION
Refer to DTC P2195 (See page ES-355).
DTC P2238Oxygen (A/F) Sensor Pumping Current Circuit
Low (Bank 1 Sensor 1)
DTC P2239Oxygen (A/F) Sensor Pumping Current Circuit
High (Bank 1 Sensor 1)
DTC P2241Oxygen (A/F) Sensor Pumping Current Circuit
Low (Bank 2 Sensor 1)
DTC P2242Oxygen (A/F) Sensor Pumping Current Circuit
High (Bank 2 Sensor 1)
DTC P2252Oxygen (A/F) Sensor Reference Ground Circuit
Low (Bank 1 Sensor 1)
DTC P2253Oxygen (A/F) Sensor Reference Ground Circuit
High (Bank 1 Sensor 1)
DTC P2255Oxygen (A/F) Sensor Reference Ground Circuit
Low (Bank 2 Sensor 1)
DTC P2256Oxygen (A/F) Sensor Reference Ground Circuit
High (Bank 2 Sensor 1)
DTC No. DTC Detection Condition Trouble Area
P2238
P2241•Case 1:
Condition (a) or (b) continues for 5.0 seconds or
more (1 trip detection logic):
(a) AF+ voltage is 0.5 V or less
(b) (AF+) - (AF-) = 0.1 V or less
•Case 2:
A/F sensor admittance: Less than 0.022 1/
(2 trip
detection logic)• Open or short in A/F sensor (bank 1, 2 sensor 1)
circuit
• A/F sensor (bank 1, 2 sensor 1)
• A/F sensor heater (bank 1, 2 sensor 1)
• A/F sensor heater relay
• A/F sensor heater and relay circuits
•ECM
P2239
P2242AF+ voltage is more than 4.5 V for 5.0 seconds or more
(2 trip detection logic)• Open or short in A/F sensor (bank 1, 2 sensor 1)
circuit
• A/F sensor (bank 1, 2 sensor 1)
• A/F sensor heater
• A/F sensor heater relay
• A/F sensor heater and relay circuits
•ECM

2GR-FE ENGINE CONTROL SYSTEM – SFI SYSTEMES–381
ESHINT:
• DTC P2238, P2239, P2252 and P2253 indicate malfunctions related to the bank 1 A/F sensor circuit.
• DTC P2241, P2242, P2255 and P2256 indicate malfunctions related to the bank 2 A/F sensor circuit.
• Bank 1 refers to the bank that includes cylinder No. 1.
• Bank 2 refers to the bank that includes cylinder No. 2.
MONITOR DESCRIPTION
The Air-Fuel Ratio (A/F) sensor varies its output voltage in proportion to the air-fuel ratio. If the A/F sensor
impedance (alternating current resistance) or voltage output deviates greatly from the standard range, the
ECM determines that there is an open or short malfunction in the A/F sensor circuit.
MONITOR STRATEGY
TYPICAL ENABLING CONDITIONS
All:
P2238 and P2241 (open circuit between AF+ and AF-):
P2252
P2255AF-voltage is 0.5 V or less for 5.0 seconds or more (2
trip detection logic)• Open or short in A/F sensor (bank 1, 2 sensor 1)
circuit
• A/F sensor (bank 1, 2 sensor 1)
• A/F sensor heater
• A/F sensor heater relay
• A/F sensor heater and relay circuits
•ECM
P2253
P2256AF-voltage is more than 4.5 V for 5.0 seconds or more
(2 trip detection logic)• Open or short in A/F sensor (bank 1, 2 sensor 1)
circuit
• A/F sensor (bank 1, 2 sensor 1)
• A/F sensor heater
• A/F sensor heater relay
• A/F sensor heater and relay circuits
•ECM
Related DTCsP2238: A/F sensor (Bank 1) open circuit between AF+ and AF-
P2238: A/F sensor (Bank 1) short circuit between AF+ and AF-
P2238: A/F sensor (Bank 1) short circuit between AF+ and GND
P2239: A/F sensor (Bank 1) short circuit between AF+ and +B
P2241: A/F sensor (Bank 2) open circuit between AF+ and AF-
P2241: A/F sensor (Bank 2) short circuit between AF+ and AF-
P2241: A/F sensor (Bank 2) short circuit between AF+ and GND
P2242: A/F sensor (Bank 2) short circuit between AF+ and +B
P2252: A/F sensor (Bank 1) short circuit between AF- and GND
P2253: A/F sensor (Bank 1) short circuit between AF- and +B
P2255: A/F sensor (Bank 2) short circuit between AF- and GND
P2256: A/F sensor (Bank 2) short circuit between AF- and +B
Required Sensors / Components (Main) A/F sensor
Required Sensors / Components (Related) Engine Coolant Temperature (ECT) sensor, Crankshaft position sensor
Frequency of Operation Once per driving cycle
DurationP2238 and P2241 (open circuit between AF+ and AF-): 10 seconds
Others: 5 seconds
MIL Operation 2 driving cycles
Sequence of Operation None
The monitor will run whenever these DTCs are not
presentNone
AF+ terminal voltage 0.5 to 4.5 V
AF- terminal voltage 0.5 to 4.5 V
Difference between AF+ terminal and AF- terminal
voltage0.1 to 0.8 V
ECT 5
C (41F) or more (varies with ECT at engine start) DTC No. DTC Detection Condition Trouble Area

ES–3822GR-FE ENGINE CONTROL SYSTEM – SFI SYSTEM
ES
Others:
TYPICAL MALFUNCTION THRESHOLDS
P2238 and P2241 (Open circuit between AF+ and AF-):
P2238 and P2241 (Short circuit between AF+ and GND):
P2238 and P2241 (Short circuit between AF+ and AF-):
P2239 and P2242 (Short circuit between AF+ and +B):
P2252 and P2255 (Short circuit between AF- and GND):
P2253 and P2256 (Short circuit between AF- and +B):
WIRING DIAGRAM
Refer to DTC P2195 (See page ES-359).
INSPECTION PROCEDURE
HINT:
For use of the intelligent tester only:
Malfunctioning areas can be identified by performing the A/F CONTROL function provided in the ACTIVE
TEST. The A/F CONTROL function can help to determine whether the Air-Fuel Ratio (A/F) sensor, Heated
Oxygen (HO2) sensor and other potential trouble areas are malfunctioning.
The following instructions describe how to conduct the A/F CONTROL operation using the intelligent
tester.
(a) Connect the intelligent tester to the DLC3.
(b) Start the engine and turn the tester on.
(c) Warm up the engine at an engine speed of 2500 rpm for approximately 90 seconds.
(d) Select the following menu items on the tester: DIAGNOSIS / ENHANCED OBD II / ACTIVE TEST / A/
F CONTROL.
(e) Perform the A/F CONTROL operation with the engine in an idling condition (press the RIGHT or LEFT
button to change the fuel injection volume).
Engine Running
Fuel-cut OFF
Time after fuel-cut OFF 5 seconds or more
A/F sensor heater ON
Battery voltage 11 V or more
Ignition switch ON
Time after ignition switch is OFF to ON 5 seconds or more
Battery voltage 11 V or more
Ignition switch ON
Time after ignition switch is OFF to ON 5 seconds or more
A/F sensor admittance Below 0.022 1/
AF+ terminal voltage 0.5 V or less
Difference between AF+ terminal and AF- terminal
voltage0.1 V or less
AF+ terminal voltage More than 4.5 V
AF- terminal voltage 0.5 V or less
AF- terminal voltage More than 4.5 V

2GR-FE ENGINE CONTROL SYSTEM – SFI SYSTEMES–383
ES
(f) Monitor the voltage outputs of the A/F and HO2 sensors (AFS B1S1 and O2S B1S2 or AFS B2S1 and
O2S B2S2) displayed on the tester.
HINT:
• The A/F CONTROL operation lowers the fuel injection volume by 12.5% or increases the injection
volume by 25%.
• Each sensor reacts in accordance with increases and decreases in the fuel injection volume.
Standard voltage
NOTICE:
The Air-Fuel Ratio (A/F) sensor has an output delay of a few seconds and the Heated Oxygen
(HO2) sensor has a maximum output delay of approximately 20 seconds.
Tester Display (Sensor) Injection Volumes Status Voltages
AFS B1S1 or AFS B2S1 (A/F) +25% Rich Less than 3.0
AFS B1S1 or AFS B2S1 (A/F) -12.5% Lean More than 3.35
O2S B1S2 or O2S B2S2 (HO2) +25% Rich More than 0.55
O2S B1S2 or O2S B2S2 (HO2) -12.5% Lean Less than 0.4
CaseA/F Sensor (Sensor 1)
Output VoltageHO2 Sensor (Sensor 2)
Output VoltageMain Suspected
Trouble Area
1-
2•A/F sensor
•A/F sensor
heater
•A/F sensor
circuit
3•HO2 sensor
• HO2 sensor
heater
• HO2 sensor
circuit

ES–3842GR-FE ENGINE CONTROL SYSTEM – SFI SYSTEM
ES– Following the A/F CONTROL procedure enables technicians to check and graph the voltage outputs of
both the A/F and HO2 sensors.
– To display the graph, select the following menu items on the tester: DIAGNOSIS / ENHANCED OBD II
/ ACTIVE TEST / A/F CONTROL / USER DATA / AFS B1S1 and O2S B1S2 or AFS B2S1 and O2S
B2S2. Press the YES button and then the ENTER button. Then press the F4 button.
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 low A/F sensor voltage could be caused by a rich air-fuel mixture. Check for conditions that would
cause the engine to run rich.
• A high A/F sensor voltage could be caused by a lean air-fuel mixture. Check for conditions that
would cause the engine to run lean.
(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
4•Fuel pressure
• Gas leakage
from exhaust
system
(Air-fuel ratio
extremely lean
or rich)
1INSPECT AIR FUEL RATIO SENSOR (HEATER RESISTANCE)
CaseA/F Sensor (Sensor 1)
Output VoltageHO2 Sensor (Sensor 2)
Output VoltageMain Suspected
Trouble Area
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

2GR-FE ENGINE CONTROL SYSTEM – SFI SYSTEMES–385
ES
B
C
A
(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
(c) Reinstall the A/F relay.
NG
OKREPLACE AIR FUEL RATIO SENSOR (See
page EC-19)
REPLACE AIR FUEL RATIO SENSOR (See
page EC-26)
2INSPECT RELAY (A/F RELAY)
B016200
Tester Connection Specified Condition
3 - 5 10 k
or higher
3 - 5Below 1
(when battery voltage applied to terminals 1 and
2)
REPLACE RELAY (A/F RELAY)

ES–3862GR-FE ENGINE CONTROL SYSTEM – SFI SYSTEM
ES
(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) Turn the ignition switch off.
(e) Disconnect the E10 ECM connector.
(f) Measure the resistance according to the value(s) in the
table below.
Standard resistance :
Check for open
Check for short
(g) Reconnect the ECM connector.
(h) Reconnect the A/F sensor connector.
3CHECK HARNESS AND CONNECTOR (A/F SENSOR - ECM)
A136175E10
Tester Connection Specified Condition
+B (A5-2) - Body ground 9 to 14 V
+B (A6-2) - Body ground 9 to 14 V
Tester Connection Specified Condition
HT (A5-1) - HA1A (E10-2) Below 1
AF+ (A5-3) - A1A+ (E10-22) Below 1
AF- (A5-4) - A1A- (E10-30) Below 1
HT (A6-1) - HA2A (E10-1) Below 1
AF+ (A6-3) - A2A+ (E10-23) Below 1
AF- (A6-4) - A2A- (E10-31) Below 1
Tester Connection Specified Condition
HT (A5-1) or HA1A (E10-2) - Body ground 10 k
or higher
AF+ (A5-3) or A1A+ (E10-22) - Body ground 10 k
or higher
AF- (A5-4) or A1A- (E10-30) - Body ground 10 k
or higher
HT (A6-1) or HA2A (E10-1) - Body ground 10 k
or higher
AF+ (A6-3) or A2A+ (E10-23) - Body ground 10 k
or higher
AF- (A6-4) or A2A- (E10-31) - Body ground 10 k
or higher

2GR-FE ENGINE CONTROL SYSTEM – SFI SYSTEMES–387
ES
NG
OK
A165205E01
REPAIR OR REPLACE HARNESS OR
CONNECTOR (A/F SENSOR - ECM)
REPLACE ECM (See page ES-498)