engine TOYOTA SIENNA 2007 Service Repair Manual

ES–3702GR-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.
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
4•Fuel pressure
• Gas leakage
from exhaust
system
(Air-fuel ratio
extremely lean
or rich)

2GR-FE ENGINE CONTROL SYSTEM – SFI SYSTEMES–371
ES
– 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) 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 P2195, P2196, P2197 or P2198
are output, troubleshoot those DTCs first.
B
A
(a) Connect the intelligent tester to the DLC3.
(b) Turn the ignition switch to the ON position and turn the
tester on.
(c) Clear the DTCs (See page ES-39).
(d) Allow the vehicle to drive in accordance with the driving
pattern described in the CONFIRMATION DRIVING
PAT T E R N .
(e) Select the following menu items on the tester:
DIAGNOSIS / ENHANCED OBD II / MONITOR INFO /
MONITOR STATUS.
(f) Check that the status of O2S MON is COMPL.
If the status is still INCMPL, drive the vehicle according
to the driving pattern again.
HINT:
• AVAIL indicates that the component has not been
monitored yet.
1CHECK ANY OTHER DTCS OUTPUT (IN ADDITION TO P2195, P2196, P2197 OR P2198)
Display (DTC Output) Proceed to
P2195, P2196, P2197 or P2198 A
P2195, P2196, P2197 or P2198 and other DTCs B
DTC CAUSED BY RUNNING OUT OF FUEL
2READ VALUE OF INTELLIGENT TESTER (TEST VALUE OF A/F SENSOR)

ES–3722GR-FE ENGINE CONTROL SYSTEM – SFI SYSTEM
ES
• COMPL indicates that the component is functioning
normally.
• INCMPL indicates that the component is
malfunctioning.
(g) Select the following menu items: DIAGNOSIS /
ENHANCED OBD II / MONITOR INFO / TEST RESULT /
RANGE B1S1, then press the ENTER button.
(h) Check the test value of the A/F sensor output current
during fuel-cut.
Result
B
A
(a) Connect the intelligent tester to the DLC3.
(b) Start the engine.
(c) Turn the tester on.
(d) Warm up the Air-Fuel Ratio (A/F) sensor at an engine
speed of 2500 rpm for 90 seconds.
(e) Select the following menu items on the tester:
DIAGNOSIS / ENHANCED OBD II / SNAPSHOT /
MANUAL SNAPSHOT / USER DATA / AFS B1S1 or AFS
B2S1 and ENGINE SPD.
(f) Check the A/F sensor voltage 3 times, when the engine
is in each of the following conditions:
(1) While idling (check for at least 30 seconds) (Step
(1))
(2) At an engine speed of approximately 2500 rpm
(without any sudden changes in engine speed)
(Step (2))
(3) Raise the engine speed to 4000 rpm and then
quickly release the accelerator pedal so that the
throttle valve is fully closed (Step (3)).
Standard voltage
HINT:
For more information, see the diagrams below.
Test Value Proceed to
Within normal range (1.4 mA or more, and less than 3.6 mA) A
Outside normal range (Less than 1.4 mA, or 3.6 mA or more) B
Go to step 20
3READ VALUE OF INTELLIGENT TESTER (OUTPUT VOLTAGE OF A/F SENSOR)
Conditions A/F Sensor Voltage Variations Reference
Steps (1) and (2) Changes at approximately 3.3 V Between 3.1 V and 3.5 V
Step (3) Increases to 3.8 V or moreThis occurs during engine deceleration
(when fuel-cut performed)

2GR-FE ENGINE CONTROL SYSTEM – SFI SYSTEMES–373
ES
HINT:
• If the output voltage of the A/F sensor remains at
approximately 3.3 V (see Malfunction Condition
diagram) under any conditions, including those
described on the previous page, the A/F sensor
may have an open circuit. (This will also happen
if the A/F sensor heater has an open circuit.)
• If the output voltage of the A/F sensor remains at
either approximately 3.8 V or more, or 2.8 V or
less (see Malfunction Condition diagram) under
any conditions, including those described on the
previous page, the A/F sensor may have a short
circuit.
• The ECM stops fuel injection (fuel cut) during
engine deceleration. This causes a lean
condition and results in a momentary increase in
the A/F sensor output voltage.
• The ECM must establish a closed throttle valve
position learning value to perform fuel cut. If the
battery terminal has been reconnected, the
vehicle must be driven over 10 mph (16 km/h) to
allow the ECM to learn the closed throttle valve
position.
• When the vehicle is driven:
The output voltage of the A/F sensor may be
below 2.8 V during fuel enrichment. For the
vehicle, this translates to a sudden increase in
speed with the accelerator pedal fully depressed
when trying to overtake another vehicle. The A/F
sensor is functioning normally.
A072304E24

ES–3742GR-FE ENGINE CONTROL SYSTEM – SFI SYSTEM
ES
• The A/F sensor is a current output element;
therefore, the current is converted into a voltage
inside the ECM. Measuring the voltage at the
connectors of the A/F sensor or ECM will show a
constant voltage result.
NG
OK
NEXT
(a) Read DTCs using the intelligent tester.
(b) Select the following menu items: DIAGNOSIS /
ENHANCED OBD II / DTC INFO / PENDING CODES.
Result
B
A
(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 Go to step 10
4PERFORM CONFIRMATION DRIVING PATTERN
5CHECK WHETHER DTC OUTPUT RECURS (DTC P2195, P2196, P2197 OR P2198)
Display (DTC Output) Proceed to
P2195, P2196, P2197 or P2198 A
No output B
Go to step 9
6REPLACE AIR FUEL RATIO SENSOR
7PERFORM CONFIRMATION DRIVING PATTERN
8CHECK WHETHER DTC OUTPUT RECURS (DTC P2195, P2196, P2197 OR P2198)
Display (DTC Output) Proceed to
No output A
P2195, P2196, P2197 or P2198 B

2GR-FE ENGINE CONTROL SYSTEM – SFI SYSTEMES–375
ES
B
A
(a) Has the vehicle run out of fuel in the past?.
NO
YES
(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
AREPLACE ECM
9CONFIRM WHETHER VEHICLE HAS RUN OUT OF FUEL IN PAST
CHECK FOR INTERMITTENT PROBLEMS
DTC CAUSED BY RUNNING OUT OF FUEL
10INSPECT AIR FUEL RATIO SENSOR (HEATER RESISTANCE)
A126269E35
Tester Connection Specified Condition
HT (1) - +B (2) 1.8 to 3.4
at 20C (68F)
HT (1) - AF- (4) 10 k
or higher
Tester Connection Specified Condition
HT (1) - +B (2) 1.8 to 3.4
at 20C (68F)
HT (1) - AF- (4) 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)

ES–3762GR-FE ENGINE CONTROL SYSTEM – SFI SYSTEM
ES
(a) Remove the A/F relay from 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
OK
(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
11INSPECT 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)
12CHECK 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–377
ES
(g) Reconnect the ECM connector.
(h) Reconnect the A/F sensor connector.
NG
OK
(a) Check the intake system for vacuum leakage.
OK:
No leakage from intake system.
NG
OK
(a) Check the fuel pressure (See page FU-7).
NG
OK
(a) Check the injector injection (whether fuel volume is high
or low, and whether injection pattern is poor) (See page
FU-16).
A165205E01
REPAIR OR REPLACE HARNESS OR
CONNECTOR (A/F SENSOR - ECM)
13CHECK INTAKE SYSTEM
REPAIR OR REPLACE INTAKE SYSTEM
14CHECK FUEL PRESSURE (HIGH PRESSURE SIDE AND LOW PRESSURE SIDE)
REPAIR OR REPLACE FUEL SYSTEM
15INSPECT FUEL INJECTOR ASSEMBLY

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