TOYOTA AVENSIS 2005 Service Repair Manual

A00798
Atmosphere
Housing
Platinum Electrode
Solid Electrolyte
(Zirconia Element)
Platinum Electrode
Heater
Coating (Ceramic)
Exhaust Gas CoverIdeal Air−Fuel Mixture
Output Voltage
Richer−Air Fuel Ratio−Leaner
− DIAGNOSTICSSFI SYSTEM (2AZ−FSE)
05−83
AVENSIS Supplement (RM1045E)
CIRCUIT DESCRIPTION
To obtain a high purification rate for the CO, HC and NOx components of the exhaust gas, a three−way cata-
lytic converter is used. For the most efficient use of the three−way catalytic converter, the air−fuel ratio must
be precisely controlled so that it is always close to the stoichiometric air−fuel ratio.
The heated oxygen sensor has the characteristic whereby its output voltage changes suddenly in the vicinity
of the stoichiometric air−fuel ratio. This is used to detect the oxygen concentration in the exhaust gas and
to provide the ECM with feedback to control the air−fuel ratio.
When the air−fuel ratio becomes LEAN, the oxygen concentration in the exhaust gas increases. And the
heated oxygen sensor informs the ECM of the LEAN condition (low voltage, i. e. less than 0.45 V).
When the air−fuel ratio is RICHER than the stoichiometric air−fuel ratio, the oxygen concentration in the ex-
haust gas is reduced. And the heated oxygen sensor informs the ECM of the RICH condition (high voltage,
i. e. more than 0.45 V). The ECM judges whether the air−fuel ratio is RICH or LEAN by voltage from the
heated oxygen sensor, and controls the injection timing accordingly. However, if the malfunction of the
heated oxygen sensor causes abnormal voltage output, the ECM becomes unable to perform the accurate
air−fuel ratio control.
The heated oxygen sensors include a heater which heats the zirconia element. The heater is controlled by
the ECM. When the intake air volume is low (the temperature of the exhaust gas is low), the current flows
to the heater in order to heat the sensor for the accurate oxygen concentration detection.

05−84
− DIAGNOSTICSSFI SYSTEM (2AZ−FSE)
AVENSIS Supplement (RM1045E) DTC No.
DTC Detection ConditionTrouble Area
P0130
P0150After engine is warmed up, output voltage of heated oxygen
sensor remains at 0.4 V or more, or 0.55 V or less, during id-
ling (2 trip detection logic)
SOpen or short in heated oxygen sensor circuit
SHeated oxygen sensor (Bank1, 2 Sensor1)
SHeated oxygen sensor heater (Bank1, 2 Sensor1)
SEFI relay
SAir induction system
SFuel pressure
SInjector
SECM
P2195
P2197After engine is warmed up, output voltage of heated oxygen
sensor remains at 0.55 V or less, during idling (2 trip detection
logic)
SOpen or short in heated oxygen sensor circuit
SHeated oxygen sensor (Bank1, 2 Sensor1)
SHeated oxygen sensor heater (Bank1, 2 Sensor1)
SEFI relay
SAir induction system
SFuel pressure
SInjector
SECM
P2196
P2198After engine is warmed up, output voltage of heated oxygen
sensor remains at 0.4 V or more, during idling (2 trip detection
logic)
SOpen or short in heated oxygen sensor circuit
SHeated oxygen sensor (Bank1, 2 Sensor1)
SHeated oxygen sensor heater (Bank1, 2 Sensor1)
SEFI relay
SAir induction system
SFuel pressure
SInjector
SECM
HINT:
SBank1refers to the No.1and No. 4 cylinders.
SBank 2 refers to the No. 2 and No. 3 cylinders.
SSensor1refers to the sensor closest to the engine assembly.
SThe output voltage of the heated oxygen sensor and the short−term fuel trim value can be read using
the hand−held tester.

A76864
ECM
MREL
HT1B 8
E9
E12 25 H8
Heated Oxygen Sensor (Bank1Sensor 2)
4 21
3P
B
W−B 4
2
1
D 2
12
4A
W−B
Battery
EC 1 3
5
J/C
FL MAIN
E B−W
EEBR(*1)
*1: Shielded 4EFI
No. 2Engine
Room
R/B No. 4
B−WB−W
13
EA1
Engine Room
R/B No. 4EFI
Relay
B−Y 44
44
1
4B 1Engine Room
J/B No. 4 B−G
B−G EFI 1
1A 1Engine
Room
R/B No.1
J13
J12BR EDJ12
J13DJ12
J/C BR
BR GRGR
OX1B E12 21
W B−WB−W
B−W2
IE1
O1B− E11 26 GR
(*1)
(*1)HT2B
E12 33 H10
Heated Oxygen Sensor
(Bank 2 Sensor 2)
4 2
1
3L−B
R (*1)
OX2B E12 29
G B−W
B−WO2B− E11 31
HT1A E12 5 H7
Heated Oxygen Sensor
(Bank1Sensor1)
4 2
1
3Y
B
(*1)OX1A E12 22
BR B−W
B−W
E2 E13 28 BR
BR(*1)
HT2A E12 4
H9
Heated Oxygen Sensor
(Bank 2 Sensor1) 4
2
1 3
LR
OX2A E12 23
B−W Engine
Room
J/B No.1
− DIAGNOSTICSSFI SYSTEM (2AZ−FSE)
05−85
AVENSIS Supplement (RM1045E)
WIRING DIAGRAM

A89553
Vehicle speed(25 mph)40 km/h
Ignition switch OFF (a) (b) Engine is
warming
−up
Idling (c)
(d)
(e)
30 seconds
or more (f)
30 seconds
25 seconds
or more
(e)
30 seconds
or more
25 seconds
or more
25 seconds
or more
05
−86
−
DIAGNOSTICS SFI SYSTEM (2AZ−FSE)
AVENSIS Supplement (RM 1045E)
CONFIRMATION DRIVING PATTERN
(a) Connect the hand −held tester to the DLC3.
(b) Switch the hand −held tester from normal mode to check mode (see page 05 −20).
(c) Start the engine and let the engine idle.
(d) Drive the vehicle at 40 km/h (25 mph) or more for 25 seconds or more.
(e) Let the engine idle for 30 seconds or more. Perform steps (d) and (e) at least 3 times.
(f) Let the engine idle for 30 seconds.
HINT:
If malfunction exists, the CHK ENG will be illuminated during step (f).
NOTICE:
If the conditions in this test are not strictly followed, no malfunction will be detected.
If you do not have the hand −held tester, turn the ignition switch to OFF after performing steps from
(c) to (f), then perform steps (c) to (f) again.

+25 %
−12.5 %
More than 0.5 V
Less than 0.4V
Case1
Case 2
Case 3
Case 4
Output voltage of heated oxygen
sensor (sensor1: front sensor)
Injection volume
Output voltage
Output voltage of heated oxygen
sensor (sensor 2: rear sensor)Main suspect
trouble area
OK
+25 %
−12.5 %
More than 0.5 V
Less than 0.4V
Injection volume
Output voltage
+25 %
−12.5 %
More than 0.5 V
Less than 0.4V
Injection volume
Output voltage
Sensor1: front sensor
(sensor1, heater, sensor1
circuit)+25 %
−12.5 %
More than 0.5 V
Less than 0.4V
Injection volume
Output voltage
+25 %
−12.5 %
Injection volume
Output voltage
NG
+25 %
−12.5 %
Injection volume
Output voltage
NG
+25 %
−12.5 %
Injection volume
Output voltage
NG
+25 %
−12.5 %
Injection volume
Output voltage
NGExtremely rich or lean actual
air−fuel ratio
(Injector, fuel pressure, gas
leakage in exhaust system,
etc.) OK
OK
OK
Almost no reaction


Sensor 2: rear sensor
(sensor 2, heater, sensor 2
circuit)
Almost no reaction Almost no reactionAlmost no reaction
− DIAGNOSTICSSFI SYSTEM (2AZ−FSE)
05−87
AVENSIS Supplement (RM1045E)
INSPECTION PROCEDURE
HINT:
Hand−held tester only:
It is possible the malfunctioning area can be found using the ACTIVE TEST A/F CONTROL operation. The
A/F CONTROL operation can determine if the A/F sensor, heated oxygen sensor or other potential trouble
areas are malfunctioning or not.
(a) Perform the ACTIVE TEST A/F CONTROL operation.
HINT:
The A/F CONTROL operation lowers the injection volume12.5% or increases the injection volume 25%.
(1) Connect the hand−held tester to the DLC3 on the vehicle.
(2) Turn the ignition switch to ON.
(3) Warm up the engine by running the engine at 2,500 rpm for approximately 3 minutes.
(4) Select the item: DIAGNOSIS / OBD/MOBD / ACTIVE TEST / A/F CONTROL.
(5) Perform the A/F CONTROL operation with the engine in an idle condition (press the right or left
button).
Result:
Heated oxygen sensor reacts in accordance with increase and decrease of injection volume:
+25 %
rich output: More than 0.5 V
−12.5 %
lean output: Less than 0.4 V
NOTICE:
There is a delay of few seconds in the sensor1(front sensor) output, and there is about 20 seconds
delay at maximum in the sensor 2 (rear sensor).

05−88
−
DIAGNOSTICS SFI SYSTEM (2AZ−FSE)
AVENSIS Supplement (RM 1045E)
The following A/F CONTROL procedure enables the technician to check and graph the voltage outputs of
both the heated oxygen sensor.
To display the graph, enter ACTIVE TEST/ A/F CONTROL/USER DATA, then select ”O2S B 1S 1 and O2S
B 1S2” or ”O2S B2S 1 and O2S B2S2” by pressing the ”YES” button followed by the ”ENTER” button and then
the ”F4” button.
NOTICE:
If the vehicle is short of fuel, the air −fuel ratio becomes LEAN and heated oxygen sensor DTCs will
be recorded, and the CHK ENG then illuminates.
HINT:
S If different DTCs related to different systems that have terminal E2 as the ground terminal are output
simultaneously, terminal E2 may have an open circuit.
S 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, and other data from the time the malfunction occurred.
S A high heated oxygen sensor (sensor 1) voltage (0.5 V or more) could be caused by a rich air −fuel
mixture. Check for conditions that would cause the engine to run rich.
S A low heated oxygen sensor (sensor 1) voltage (0.4 V or less) could be caused by a lean air −fuel mix-
ture. Check for conditions that would cause the engine to run lean.
1 CHECK OTHER DTC OUTPUT(IN ADDITION TO HEATED OXYGEN SENSOR
DTCS)
(a) Connect the hand −held tester to the DLC3.
(b) Turn the ignition switch to ON and turn the hand −held tester ON.
(c) Select the item: DIAGNOSIS / OBD/MOBD / DTC INFO / CURRENT CODES.
(d) Read the DTCs using the hand −held tester.
Result:
Display (DTC output)Proceed to
P0 130, P0 150, P2 195, P2 196, P2 197 and/or P2 198A
P0 130, P0 150, P2 195, P2 196, P2 197 or P2 198 and other DTCsB
HINT:
If any other codes besides P0 130, P0 150, P2 195, P2 196, P2 197 and/or P2 198 are output, perform trouble-
shooting for those DTCs first.
B GO TO RELEVANT DTC CHART(See page 05 −31)
A

P18349
−
DIAGNOSTICS SFI SYSTEM (2AZ−FSE)
05 −89
AVENSIS Supplement (RM 1045E)
2 READ VALUE OF HAND −HELD TESTER(OUTPUT VOLTAGE OF HEATED OXYGEN
SENSOR)
(a) Connect the hand −held tester to the DLC3.
(b) Start the engine and turn the hand −held tester ON.
(c) Select the item: DIAGNOSIS / OBD/MOBD / DATA LIST / ALL / O2S B 1S 1 or O2S B2S 1.
(d) Warm up the heated oxygen sensor with the engine speed at 2,500 rpm for approximately 90 seconds.
(e) Read the output voltage of the heated oxygen sensor during idling. Heated oxygen sensor (sensor 1) output voltage:
Alternates repeatedly between less than 0.4 V and more than 0.55 V (see the following table).
NG Go to step 5
OK
3 PERFORM CONFIRMATION DRIVING PATTERN
HINT:
Clear all DTCs prior to performing the confirmation driving pattern. GO
4 READ OUTPUT DTC(SEE IF HEATED OXYGEN SENSOR DTCS ARE OUTPUT AGAIN)
(a) Connect the hand −held tester to the DLC3.
(b) Turn the ignition switch to ON and turn the hand −held tester ON.
(c) Select the item: DIAGNOSIS / OBD/MOBD / DTC INFO / CURRENT CODES.
(d) Read the DTCs using the hand −held tester.
Result:
Display (DTC output)Proceed to
P0 130, P0 150, P2 195, P2 196, P2 197 and/or P2 198A
No outputB
B CHECK FOR INTERMITTENT PROBLEMS
(See Page 05 −7)
A
REPLACE HEATED OXYGEN SENSOR

A62378
1 2
3 4
+BHT
E1
OX
B1S1 H7
Heated Oxygen Sensor Component Side:
Front View
A79112
E1OX B2S1 H9
+B
HT Heated Oxygen Sensor
Component Side:
Front View
B16200
05−90
− DIAGNOSTICSSFI SYSTEM (2AZ−FSE)
AVENSIS Supplement (RM1045E)
5 INSPECT HEATED OXYGEN SENSOR(HEATER RESISTANCE)
(a) Disconnect the H7 or H9 heated oxygen sensor connec-
tor.
(b) Measure the resistance between the terminals of the
heated oxygen sensor connector.
Standard (Bank1, 2 Sensor1):
Tester ConnectionResistance
1(HT)−2 (+B)11to16
at 20_C (68_F)
1(HT)−4(E1)10k
or higher
(c) Reconnect the heated oxygen sensor connector.
NG REPLACE HEATED OXYGEN SENSOR
OK
6 INSPECT EFI RELAY
(a) Remove the EFI relay from the engine room R/B No. 4.
(b) Check for continuity in the EFI relay.
Standard:
Tester ConnectionSpecified Condition
1−2Continuity
3−5No Continuity
3−5Continuity
(Apply battery voltage to terminals1and 2)
(c) Reinstall the EFI relay.
NG REPLACE EFI RELAY
OK

A76821
Wire Harness Side:
B1S1B2S1 H7 H9
Heated Oxygen Sensor Connector OX
HT
OX
HT
E1E1
A76823
OX2A
ECM Connector E12
OX1A
HT2A HT1A
E2 E13
A72920
Reference (Bank1Sensor1System Drawing)
Heated Oxygen Sensor
EFI Relay
Heater
Sensor
OX1A HT1A
Duty
Control ECM
From
Battery
EFI Fuse
E2 EFI No. 2
Fuse
MREL OX HT
E1 +B
− DIAGNOSTICSSFI SYSTEM (2AZ−FSE)
05−91
AVENSIS Supplement (RM1045E)
7 CHECK HARNESS AND CONNECTOR(HEATED OXYGEN SENSOR−ECM)
(a) Disconnect the H7 or H9 heated oxygen sensor connec-
tor.
(b) Disconnect the E12 and E13 ECM connectors.
(c) Check the resistance between the wire harness side con-
nectors.
Standard (Check for open):
Tester ConnectionSpecified Condition
OX (H7−3)−OX1A(E12−22)Below1

HT (H7−1)−HT1A(E12−5)Below1

E1(H7−4)−E2 (E13−28)Below1

OX (H9−3)−OX2A (E12−23)Below1

HT (H9−1)−HT2A (E12−4)Below1

E1(H9−4)−E2 (E13−28)Below1

Standard (Check for short):
Tester ConnectionSpecified Condition
OX (H7−3) or OX1A(E12−22)−Body ground10k
or higher
HT (H7−1)orHT1A(E12−5)−Body ground10k
or higher
OX (H9−3) or OX2A (E12−23)−Body ground10k
or higher
HT (H9−1) or HT2A (E12−4)−Body ground10k
or higher
(d) Reconnect the heated oxygen sensor connector.
(e) Reconnect the ECM connector.
HINT:
SThe OX1A and HT1A means the heated oxygen sensor
bank1sensor1.
SThe OX2A and HT2A means the heated oxygen sensor
bank 2 sensor1.
NG REPAIR OR REPLACE HARNESS OR
CONNECTOR
OK

05−92
−
DIAGNOSTICS SFI SYSTEM (2AZ−FSE)
AVENSIS Supplement (RM 1045E)
8 CHECK AIR INDUCTION SYSTEM
(a) Check for vacuum leaks in the air induction system.
NG REPAIR OR REPLACE AIR INDUCTION SYSTEM
OK
9 CHECK FUEL PRESSURE(LOW PRESSURE) (See page 11− 4)
NG CHECK AND REPLACE FUEL PUMP,
PRESSURE REGULATOR, FUEL PIPE LINE AND
FILTER
OK
1 0 CHECK FUEL PRESSURE(HIGH PRESSURE) (See page 11− 4)
NG CHECK AND REPLACE FUEL PUMP, FUEL
PRESSURE SENSOR, WIRING AND FUEL
LEAKAGE
OK
11 CONFIRM IF ANY MISFIRING DTCS WERE PRESENT AT STEP 1
(a) Misfiring DTC P0301, P0302, P0303 and/or P0304 was present at step 1.
NO REPLACE HEATED OXYGEN SENSOR
YES
1 2 REPLACE FUEL INJECTOR ASSY (See page 11−1 3)
HINT:
If one or more the misfiring DTCs P030 1, P0302, P0303 and/or P0304 were present at step 1, replace the
injector(s) mounted on the misfiring cylinder(s) that is referred by the DTC(s) with normal injector(s).
GO
13 PERFORM CONFIRMATION DRIVING PATTERN
HINT:
Clear all DTCs prior to performing the confirmation driving pattern.
GO