2005 TOYOTA AVENSIS sensor

A66651A±A SectionAir Solid Electrolyte
(Zirconia Element)
Platinum ElectrodeHeater
Exhaust Gas
CoverIdeal Air±Fuel Mixture
Output Voltage
Richer ± Air Fuel Ratio ± Leaner Element
AA
± DIAGNOSTICSSFI SYSTEM (1AZ±FE)
05±211
AVENSIS REPAIR MANUAL (RM1018E)
DTC P0136/27 OXYGEN SENSOR CIRCUIT MALFUNCTION
(BANK 1 SENSOR 2)
DTC P0156/29 OXYGEN SENSOR CIRCUIT MALFUNCTION
(BANK 2 SENSOR 2)
CIRCUIT DESCRIPTION
The heated oxygen sensor is the lamination type. Compared to the conventional type, the sensor and heater
portions of the lamination type are narrower overall. Because the heat of the heater acts directly on the alumi-
na and zirconia (of the sensor portion) it accelerates the activation of the sensor.
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. But 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 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 by the voltage output from the heated oxygen sensor whether the
air±fuel ratio is RICH or LEAN and controls the injection time accordingly. However, 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 NoDTC Detection ConditionTrouble Area
The following condition continues for 480 sec. or more:
Open or short in heated oxygen sensor (bank 1, 2 sensor 2)
circuitP0136/27
P0156/29
g

During driving with the engine warmed up, voltage output of
the heated oxygen sensor remains at 0.45 V or more, or 0.60circuit

Heated oxygen sensor (bank 1, 2 sensor 2)
Heated o gen sensor heater (bank 1 2 sensor 2)P0156/29the heated oxygen sensor remains at 0.45 V or more, or 0.60
V or less.
Heated oxygen sensor heater (bank 1, 2 sensor 2)

EFI relay
05C6X±01

A76884
B±W
GR GR2
IE1
E98ECM
MREL
44
31Engine Room R/B No.4
4EFI No.2
4
1
2B±W
EA113
B±W
52EFI
RelayEngine Room
R/B No.4
44H8
Heated Oxygen Sensor
(Bank 1 Sensor 2)
2
43 1IK14
L4
E10HT1B
21
E12 OX1B
32
E13O1B± WB
(*1) B±W
B±WH10
Heated Oxygen Sensor
(Bank 2 Sensor 2)
21L±R10
IK1L±R3
HT2B
E10 J12BR
D
J/C EFI 2
1
1A 11B±YW±B
Engine
Room
R/B No.1
Engine
Room
J/B No.1
43R
G
(*1)29
OX2B E12
O2B± 31
E13
*1: Shielded
EF ECBR J12 J/CJ13BR
D
EJ13
E B±G
Engine Room
J/B No.4 4A
4B 1 1
B±G
FL MAIN
BatteryL 05±212
± DIAGNOSTICSSFI SYSTEM (1AZ±FE)
AVENSIS REPAIR MANUAL (RM1018E)
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 2 refers to the sensor farthest away from the engine assembly.
WIRING DIAGRAM

A58686
Vehicle speed40 km/h
(25 mph)
IG SW OFF Once
40 sec.
or more
60 sec.
or more 10 sec.Twice
40 sec.
or more
12 times
40 sec.
or more
10 sec.10 sec.
(
1) (

3)
(
4)
Idling(
2) (

3)
(
4) (

3)
(
5)
±
DIAGNOSTICS SFI SYSTEM(1AZ±FE)
05±213
AVENSIS REPAIR MANUAL (RM1018E)
CONFIRMATION DRIVING PATTERN
1.Connect the hand±held tester to the DLC3. (
1)
2.Switch the hand±held tester from the normal mode to the check mode (See page 05±149). (
1)
3. Start the engine and let the engine idle for 60 seconds or more. (
2)
4. Drive the vehicle at 40 km/h (25 mph) or more for 40 seconds or more. \
(
3)
5. Let the engine idle for 10 seconds or more. (
4)
6. Perform steps 4 to 5 12 times. (
5)
HINT:
If a malfunction exists, the CHK ENG will be illuminated on the multi±\
information display during step 6.
NOTICE:
If the conditions in this test are not strictly followed, detection of t\
he malfunction will be impossible.
If you do not have a hand±held tester, turn the ignition switch OFF after performing steps from 3 to
6, then perform steps from 3 to 6 again.
INSPECTION PROCEDURE
HINT:
Hand±held tester only:
Narrowing down the trouble area is possible by performing ACTIVE TEST of the following \
ºA/F CONTROLº
(A/F sensor, heated oxygen 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 with the engine speed 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:
A/F sensor reacts in accordance with increase and decrease of injection \
volume:
+25 %
rich output: Less than 3.0 V
±12.5 %
lean output: More than 3.35 V
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

+25 %
±12.5 %
More than 3.35 V
Less than 3.0 V
Case 1
Case 2
Case 3
Case 4
Output voltage of A/F sensor
(sensor 1)
Injection volume
Output voltage
Output voltage of heated oxygen
sensor (sensor 2)Mainly suspect
trouble area
OK
+25 %
±12.5 %
More than 3.35 V
Less than 3.0V
Injection volume
Output voltage
+25 %
±12.5 %
More than 0.55 V
Less than 0.4V
Injection volume
Output voltage
A/F sensor
(A/F sensor, heater, A/F sen-
sor 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


Heated oxygen sensor
(heated oxygen sensor,
heater, heated oxygen sensor
circuit) 05±214
± DIAGNOSTICSSFI SYSTEM (1AZ±FE)
AVENSIS REPAIR MANUAL (RM1018E)
NOTICE:
There is a few second delay in the A/F sensor output, and there is about 20 seconds delay in the
heated oxygen sensor output.
The following procedure of A/F CONTROL enables the technician to check and graph the voltage outputs
of both the A/F sensor and heated oxygen sensor.
For displaying the graph indication, enter ºACTIVE TEST/ A/F CONTROL/USER DATAº, then select ºAFS
B1S1 and O2S B1S2º or ºAFS B2S1 and O2S B2S2º by pressing ºYESº button and push ºENTERº button
before pressing ºF4º button.
HINT:

If different DTCs that are related to a different system are output simultaneously while terminal E2 is
used as a ground terminal, terminal E2 may be open.

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

23
4 1
A79117
+B
HT
Bank 1
Sensor 2
Bank 2
Sensor 2 H8
H10
Heated Oxygen Sensor Connector
E1
OX
±
DIAGNOSTICS SFI SYSTEM(1AZ±FE)
05±215
AVENSIS REPAIR MANUAL (RM1018E)
1READ OUTPUT DTC(BESIDES DTC P0136/27)
(a)Read the DTC.
Result:
Display (DTC output)Proceed to
Only ºP0136/27º is outputA
ºP0136/27º and other DTCs are outputB
HINT:
If any other codes besides ºP0136/27º are output, perform the troubl\
eshooting for those DTCs first.
BGO TO RELEVANT DTC CHART(See page 05±161)
A
2 READ VALUE OF HAND±HELD TESTER(OUTPUT VOLTAGE OF HEATED OXYGEN SENSOR)
(a) After warming up the engine, run the engine at 2,500 rpm for 3 minutes.
(b) Read the output voltage of the heated oxygen sensor when the engine rpm \
is suddenly increased.
HINT:
Quickly accelerate the engine to 4,000 rpm 3 times by using the accelera\
tor pedal.
Heated oxygen sensor output voltage: Alternates from 0.4 V or less to 0.\
5 V or more.
OK Go to step 6
NG
3 INSPECT HEATED OXYGEN SENSOR(HEATER RESISTANCE)
(a) Disconnect the heated oxygen sensor connector.
(b) Inspect the heated oxygen sensor. Standard:
Symbols (Terminal No.)ConditionSpecified condition
HT (H8±1) ± +B (H8±2)20
C (68
F)11 to 16

HT (H8±1) ± E1 (H8±4)
No Continuity
HT (H10±1) ± +B (H10±2)20
C (68
F)11 to 16

HT (H10±1) ± E1 (H10±4)
No Continuity
NG REPLACE HEATED OXYGEN SENSOR
OK

B16200
A79118
Wire Harness Side
Bank 1
Sensor 2
Bank 2
Sensor 2H8
H10
Heated Oxygen Sensor ConnectorOX
HT
A65747
HT1BHT2B
E12E10
ECM Connector
OX1BOX2B

A79115
Heated Oxygen Sensor
EFI Relay
Heater
Sensor
OX1B HT1B
Duty
Control ECM
From
Battery
EFI Fuse
O1B±
MREL Reference (Bank 1 Sensor 2 System Drawing)
EFI No.2 Fuse 05±216
± DIAGNOSTICSSFI SYSTEM (1AZ±FE)
AVENSIS REPAIR MANUAL (RM1018E)
4 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
5 CHECK HARNESS AND CONNECTOR(HEATED OXYGEN SENSOR ± ECM)
(a) Disconnect the H8 or H10 heated oxygen sensor connec-
tor.
(b) Disconnect the E10 and E12 ECM connector.
(c) Check for continuity between the wire harness side con-
nectors.
Standard (Check for open):
Symbols (Terminal No.)Specified condition
OX (H8±3) ± OX1B (E12±21)
HT (H8±1) ± HT1B (E10±4)ContinuityOX (H10±3) ± OX2B (E12±29)Continuity
HT (H10±1) ± HT2B (E10±3)
Standard (Check for short):
Symbols (Terminal No.)Specified condition
OX (H8±3) or OX1B (E12±21) ± Body ground
HT (H8±1) or HT1B (E10±4) ± Body groundNo continuityOX (H10±3) or OX2B (E12±29) ± Body groundNo continuity
HT (H10±1) or HT2B (E10±3) ± Body ground

±
DIAGNOSTICS SFI SYSTEM(1AZ±FE)
05±217
AVENSIS REPAIR MANUAL (RM1018E)
NGREPAIR OR REPLACE HARNESS OR
CONNECTOR
OK
REPLACE HEATED OXYGEN SENSOR
6PERFORM CONFIRMATION DRIVING PATTERN
HINT:
Clear all DTCs prior to perform the confirmation driving pattern. GO
7READ OUTPUT DTC(DTC P0136/27 IS OUTTPUT AGAIN)
(a)Read the DTC using the hand±held tester. Result:
Display (DTC output)Proceed to
ºP0136/27º is not output againA
ºP0136/27º is output againB
BREPLACE HEATED OXYGEN SENSOR
A
CHECK FOR INTERMITTENT PROBLEMS (See page 05±149)

A58684
ECM
5V
VC
VTA1
E2 Throttle Position
Sensor 05±204
± DIAGNOSTICSSFI SYSTEM (1AZ±FE)
AVENSIS REPAIR MANUAL (RM1018E)
DTC P0120/41 THROTTLE/PEDAL POSITION
SENSOR/SWITCH ºAº CIRCUIT
DTC P0122/41 THROTTLE/PEDAL POSITION
SENSOR/SWITCH ºAº CIRCUIT LOW INPUT
DTC P0123/41 THROTTLE/PEDAL POSITION
SENSOR/SWITCH ºAº CIRCUIT HIGH INPUT
CIRCUIT DESCRIPTION
The throttle position sensor is mounted in the throttle body and
detects the throttle valve opening angle.
When the throttle valve is fully closed, a voltage of approximate-
ly 0.7 V is applied to terminal VTA1 of the ECM. The voltage ap-
plied to terminal VTA1 of the ECM increases in proportion to the
opening angle of the throttle valve and becomes approximately
3.5 to 5.0 V when the throttle valve is fully opened. The ECM
judges the vehicle driving conditions from these signals input
from terminal VTA1, uses them as one of the conditions for de-
ciding the air±fuel ratio correction, power increase correction
and fuel±cut control etc.
DTC No.DTC Detection Condition
Condition (a) of DTC P0120/41, P0122/41 or P0123/41 continues for 2 sec.
(Open or short in throttle position sensor circuit)Trouble Area
P0120/41
Detection conditions for DTCs P0122 and P0123 are not satis-
fied but condition (a) is satisfied
(a) VTA1 less than 0.1 V, or VTA1 greater than 4.9 V
Throttle position sensor (built in throttle body)

ECM
P0122/41(a) VTA1 less than 0.1 V

Throttle position sensor (built in throttle body)

Short in VTA1 circuit

Open in VC circuit

ECM
P0123/41(a) VTA1 greater than 4.9 V

Throttle position sensor (built in throttle body)

Open in VTA1 circuit

Open in E2 circuit

VC and VTA1 circuit are short±circuited

ECM
NOTICE:
When a malfunction is detected, the throttle valve is locked at a certain opening angle. Also, the
whole electronically controlled throttle operation is cancelled until the system returns to normal and
the ignition switch is turned OFF.
HINT:

After confirming DTCs, use the hand±held tester to confirm the throttle valve opening percentage and
closed throttle position switch condition.
05C6W±01