2005 TOYOTA AVENSIS sensor

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
05±364
± DIAGNOSTICSSFI SYSTEM (1AZ±FSE)
AVENSIS REPAIR MANUAL (RM1018E)
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
provide the ECM with feedback 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 will be vanished from
the exhaust gas. And the heated oxygen sensor informs the ECM of the RICH condition (high voltage, i.e.
more than 0.45 V). The ECM judges by the voltage output from the heated oxygen sensor whether the air±
fuel ratio is RICH or LEAN and controls the injection time accordingly. If the malfunction of the heated oxygen
sensor causes an output of abnormal voltage, the ECM becomes unable to perform 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), current flows to the
heater in order to heat the sensor for the accurate oxygen concentration detection.
DTC No.DTC Detection ConditionTrouble Area
P0130
P0150Output voltage of heated oxygen sensor (sensor 1) remains at
0.4 V or more, or 0.55 V or less, during idling after engine is
warmed up (2 trip detection logic)
Open or short in heated oxygen sensor (bank 1, 2 sensor 1)
circuit

Heated oxygen sensor (bank 1, 2 sensor 1)
P2195
P2197Output voltage of heated oxygen sensor (sensor 1) remains at
0.55 V or less, during idling after engine is warmed up (2 trip
detection logic)
Heated oxygen sensor (bank 1, 2 sensor 1)

Heated oxygen sensor heater (bank 1, 2 sensor 1)

EFI relay

Air induction system
P2196
P2198Output voltage of heated oxygen sensor (sensor 1) remains at
0.4 V or more, during idling after engine is warmed up (2 trip
detection logic)
y

Fuel pressure

Injector

ECM
HINT:

Bank 1 refers to the No. 1 and No. 4 cylinders.

Bank 2 refers to the No. 2 and No. 3 cylinders.

Sensor 1 refers to the sensor closest to the engine assembly.

The 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
E1225 H8
Heated Oxygen Sensor (Bank 1 Sensor 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±GEFI 1
1A 1Engine
Room
R/B No. 1
and
Engine
Room
J/B No. 1
J13
J12BR ED J12
J13D J12
J/C BR
BR GRGR
OX1B E1221
W B±WB±W
B±W2
IE1
O1B± E1126 GR
(*1)
(*1)HT2B E1233 H10
Heated Oxygen Sensor
(Bank 2 Sensor 2)
4 2
1
3L±B
R (*1)
OX2B E1229
G B±W
B±WO2B± E1131
HT1A E125 H7
Heated Oxygen Sensor
(Bank 1 Sensor 1)
4 2
1
3Y
B
(*1)OX1A E1222
BR B±W
B±W
E2 E1328 BR
BR(*1)
HT2A E124
H9
Heated Oxygen Sensor
(Bank 2 Sensor 1)4
2
1 3
LR
OX2A E1223
B±W
± DIAGNOSTICSSFI SYSTEM (1AZ±FSE)
05±365
AVENSIS REPAIR MANUAL (RM1018E)
WIRING DIAGRAM

+25 %
±12.5 %
More than 0.55 V
Less than 0.4V
Case 1
Case 2
Case 3
Case 4
Output voltage of heated oxygen
sensor (sensor 1: front sensor)
Injection volume
Output voltage
Output voltage of heated oxygen
sensor (sensor 2: rear sensor)Mainly suspect
trouble area
OK
+25 %
±12.5 %
More than 0.55 V
Less than 0.4V
Injection volume
Output voltage
+25 %
±12.5 %
More than 0.55 V
Less than 0.4V
Injection volume
Output voltage
Sensor 1: front sensor
(sensor 1, heater, sensor 1
circuit)
+25 %
±12.5 %
More than 0.55 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
No reaction
No reaction
No reaction No reaction

Sensor 2: rear sensor
(sensor 2, heater, sensor 2
circuit)
± DIAGNOSTICSSFI SYSTEM (1AZ±FSE)
05±367
AVENSIS REPAIR MANUAL (RM1018E)
INSPECTION PROCEDURE
HINT:
Hand±held tester only:
Narrowing down the trouble area is possible by performing the ºA/F CONTROLº ACTIVE TEST (heated oxy-
gen sensor or other trouble areas can be distinguished).
(a) Perform ACTIVE TEST using the hand±held tester (A/F CONTROL).
HINT:
ºA/F CONTROLº is an ACTIVE TEST which changes the injection volume ±12.5 % or +25 %.
(1) Connect the hand±held tester to the DLC3 on the vehicle.
(2) Turn the ignition switch ON.
(3) Warm up the engine by running the engine at 2,500 rpm for approximately 90 sec.
(4) Select the item ºDIAGNOSIS / OBD/MOBD / ACTIVE TEST / A/F CONTROLº.
(5) Perform ºA/F CONTROLº 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 0.55 V
±12.5 %
lean output: Less than 0.4 V
NOTICE:
There is a few seconds delay in the sensor 1 (front sensor) output. And there is about 20 seconds
delay in the sensor 2 (rear sensor).

05±368
±
DIAGNOSTICS SFI SYSTEM(1AZ±FSE)
AVENSIS REPAIR MANUAL (RM1018E)
The following A/F CONTROL procedure enables the technician to check and gra\
ph the voltage outputs of
both the heated oxygen sensors.
For displaying the graph indication, enter ºACTIVE TEST / A/F CONTROL / \
USER DATAº, then select ºO2S
B1S1 and O2S B1S2º or ºO2S B2S1 and O2S B2S2º by pressing ºYESº button and push ºENTERº butto\
n
before pressing ºF4º 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 comes on.
HINT:

If different DTCs related to different systems that have terminal E2 as the ground terminal are output
simultaneously, terminal E2 may be open.

Read freeze frame data using the hand±held tester. Freeze frame data records the engine conditions
when a malfunction is detected. When troubleshooting, it is useful for deter\
mining whether the vehicle
was running or stopped, the engine was warmed up or not, the air±fuel ra\
tio was lean or rich, etc. at
the time of the malfunction.

A high heated oxygen sensor (sensor 1) voltage (0.55 V or more) coul\
d be caused by a rich air fuel
mixture. Check for conditions that would cause the engine to run rich.

A low heated oxygen sensor (sensor 1) voltage (0.4 V or less) could b\
e caused by a lean air fuel mix-
ture. Check for conditions that would cause the engine to run lean.
1CHECK OTHER DTC OUTPUT(IN ADDITION TO HEATED OXYGEN SENSOR DTCS)
(a)Read the DTC using the hand±held tester.
Result:
Display (DTC output)Proceed to
Only ºP0130, P0150, P2195, P2196, P2197 and/or P2198º are outputA
ºP0130, P0150, P2195, P2196, P2197 or P2198º and other DTCs are ou\
tputB
HINT:

If any other codes besides ºP0130, P0150, P2195, P2196, P2197 and/or P2\
198º are output, perform
the troubleshooting for those DTCs first.

If a misfiring DTC(s) is present, record the DTC(s) that indicates mis\
firing cylinder(s), then proceed to
A.
BGO TO RELEVANT DTC CHART(See page 05±309)
A

P18349
± DIAGNOSTICSSFI SYSTEM (1AZ±FSE)
05±369
AVENSIS REPAIR MANUAL (RM1018E)
2 READ VALUE OF HAND±HELD TESTER(OUTPUT VOLTAGE OF HEATED OXYGEN
SENSOR)
(a) Warm up the heated oxygen sensor (sensor 1) with the engine speed at 2,500 rpm for approximately
90 seconds.
(b) 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(HEATED OXYGEN SENSOR DTCS ARE OUTPUT AGAIN)
(a) Read the DTC using the hand±held tester.
Result:
Display (DTC output)Proceed to
ºP0130, P0150, P2195, P2196, P2197 and/or P2198º are output againA
ºP0130, P0150, P2195, P2196, P2197 and/or P2198º are not output againB
B CHECK FOR INTERMITTENT PROBLEMS
A
REPLACE HEATED OXYGEN SENSOR

A62378
Component Side
+B
HT
E1


 B1S1 H7
A61830
+B
HT
E1 Component Side
B2S1 H9
B16200
05±370
± DIAGNOSTICSSFI SYSTEM (1AZ±FSE)
AVENSIS REPAIR MANUAL (RM1018E)
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 (Bank 1, 2 Sensor 1):
Terminal No.Resistance
1 (HT) ± 2 (+B)11 to 16
at 20
C (68
F)
1 (HT) ± 4 (E1)No Continuity
NG REPLACE HEATED OXYGEN SENSOR
OK
6 INSPECT EFI RELAY
(a) Remove the EFI relay from the engine room R/B No. 4.
(b) Inspect the EFI relay.
Standard:
Terminal No.Specified condition
1 ± 2Continuity
No Continuity
3 ± 5Continuity
(Apply battery voltage terminals 1 and 2)
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 (Bank 1 Sensor 1 System 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 (1AZ±FSE)
05±371
AVENSIS REPAIR MANUAL (RM1018E)
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 for continuity between the wire harness side con-
nectors.
Standard (Check for open):
Symbols (Terminal No.)Specified condition
OX (H7±3) ± OX1A (E12±22)
HT (H7±1) ± HT1A (E12±5)
E1 (H7±4) ± E2 (E13±28)ContinuityOX (H8±3) ± OX2A (E12±23)Continuity
HT (H8±1) ± HT2A (E12±4)
E1 (H8±4) ± E2 (E13±28)
Standard (Check for short):
Symbols (Terminal No.)Specified condition
OX (H7±3) or OX1A (E12±22) ± Body ground
HT (H7±1) or HT1A (E12±5) ± Body groundNo continuityOX (H8±3) or OX2A (E12±23) ± Body groundNo continuity
HT (H8±1) or HT2A (E12±4) ± Body ground
HINT:

The OX1A and HT1A means the heated oxygen sensor
bank 1 sensor 1.

The OX2A and HT2A means the heated oxygen sensor
bank 2 sensor 1.
NG REPAIR OR REPLACE HARNESS OR
CONNECTOR
OK

05±372
±
DIAGNOSTICS SFI SYSTEM(1AZ±FSE)
AVENSIS REPAIR MANUAL (RM1018E)
8CHECK AIR INDUCTION SYSTEM
(a)Check for vacuum leaks in the air induction system. NGREPAIR OR REPLACE AIR INDUCTION SYSTEM
OK
9CHECK FUEL PRESSURE(LOW PRESSURE) (See page 11±33)
NGCHECK AND REPLACE FUEL PUMP, PRESSURE REGULATOR, FUEL PIPE LINE AND
FILTER
OK
10CHECK FUEL PRESSURE(HIGH PRESSURE) (See page 11±33)
NGCHECK AND REPLACE FUEL PUMP, FUEL PRESSURE SENSOR, WIRING AND FUEL
LEAKAGE
OK
11CONFIRM IF ANY MISFIRING DTCS WERE PRESENT AT STEP 1
(a)Misfiring DTC ºP0301, P0302, P0303 and/or P0304º was present at step 1. NOREPLACE HEATED OXYGEN SENSOR
YES
12REPLACE FUEL INJECTOR ASSY (See page 11±42)
HINT:
If one or more the misfiring DTCs ºP0301, P0302, P0303 and/or P0304º\
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