2005 TOYOTA AVENSIS sensor

+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 of the
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 (1ZZ±FE/3ZZ±FE)
05±47
AVENSIS REPAIR MANUAL (RM1018E)
INSPECTION PROCEDURE
HINT:
Hand±held tester only:
Narrowing down the trouble area is possible by performing ACTIVE TEST of the following ºA/F CONTROLº
(heated oxygen sensor or other trouble areas can be distinguished).
(a) Perform ACTIVE TEST by 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:
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 second delay in the sensor 1 (front sensor) output, and there is about 20 seconds delay
in the sensor 2 (rear sensor)output.

05±48
±
DIAGNOSTICS SFI SYSTEM(1ZZ±FE/3ZZ±FE)
AVENSIS REPAIR MANUAL (RM1018E)
The following procedure of A/F CONTROL enable the technician to check and graph voltage output of the
heated oxygen sensor.
For displaying the graph indication, enter ºACTIVE TEST / A/F CONTROL / \
USER DATA,º then select ºO2S
B1S1 and O2S B1S2º 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 \f \b\f\f
 Freeze frame data records the engine conditions
when a malfunction is detected. When troubleshooting, it is useful for d\
etermining 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(BESIDES DTC P0125)
(a)Read the DTC using the hand±held tester. Result:
Display (DTC output)Proceed to
Only ºP0125º is outputA
ºP0125º and other DTCs are outputB
HINT:
If any other codes besides ºP0125º are output, perform the troublesh\
oot on that DTC before.
BGO TO RELEVANT DTC CHART (See page 05±16)
A
2 READ VALUE OF HAND±HELD TESTER(OUTPUT VOLTAGE OF HEATED OXYGEN SENSOR)
(a) Warm up the engine to the normal operating temperature above 75 C (169 F).
(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 using the accelerator\
pedal. Standard:
Heated oxygen sensor outputs a RICH signal (0.45 V or more) at least o\
nce.
OK Go to step 13
NG

A79112
+BE2
Heated Oxygen Sensor
H7 HT
OX
A73938
+B
E2
Heated Oxygen Sensor
H17 HT
OX


 
A79069
Engine Room R/B No.4 EFI No.2 Fuse
±
DIAGNOSTICS SFI SYSTEM(1ZZ±FE/3ZZ±FE)
05±49
AVENSIS REPAIR MANUAL (RM1018E)
3INSPECT HEATED OXYGEN SENSOR(HEATER RESISTANCE)
(a)Disconnect the heated oxygen sensor connector.
(b)Inspect the heated oxygen sensor.
Standard: (Bank1 Sensor1)
Symbols (Terminal No.)ConditionSpecified condition
HT (H7±1) ± +B (H7±2)20
C (68
F)6 to 9

HT (H7±1) ± E2 (H7±4)
No Continuity
Standard: (Bank1 Sensor2)
Symbols (Terminal No.)ConditionSpecified condition
HT (H17±1) ± +B (H17±2)20
C (68
F)11 to 16

HT (H17±1) ± E2 (H17±4)
No Continuity
NGREPLACE HEATED OXYGEN SENSOR
OK
4INSPECT EFI RELAY (See page 10±3)
NG REPLACE EFI RELAY
OK
5 CHECK FUSE(EFI No.2)
(a) Remove the EFI No.2 fuse from the engine room R/B No.4.
(b) Check for continuity in the EFI fuse. Standard: Continuity
NG CHECK FOR SHORT IN ALL HARNESS AND COMPONENTS CONNECTED FUSE
OK

A79068
HT1AHT1B
E12E10
ECM Connector
OX1AOX1B
E13
E2
OX+B
E2 HT
Heated Oxygen Sensor Connector Wire Harness Side
H7
A79114
Heated Oxygen Sensor ConnectorA73939
OX+B
E2 HT
Wire Harness Side
H17
05±50
± DIAGNOSTICSSFI SYSTEM (1ZZ±FE/3ZZ±FE)
AVENSIS REPAIR MANUAL (RM1018E)
6 CHECK HARNESS AND CONNECTOR(HEATED OXYGEN SENSOR ± ECM)
(a) Disconnect the heated oxygen sensor connector.
(b) Disconnect the E10, E12 and E13 ECM connector.
(c) Check for continuity between the wire harness side con-
nectors.
Standard (Check for open): (Bank1 Sensor1)
Symbols (Terminal No.)Specified condition
HT (H7±1) ± HT1A (E12±4)
OX (H7±3) ± OX1A (E12±23)Continuity
E2 (H7±4) ± E2 (E13±28)
y
Standard (Check for short): (Bank1 Sensor1)
Symbols (Terminal No.)Specified condition
HT (H7±1) or HT1A (E12±4) ± Body groundNo continuityOX (H7±3) or OX1A (E12±23) ± Body groundNo continuity
Standard (Check for open): (Bank1 Sensor2)
Symbols (Terminal No.)Specified condition
HT (H17±1) ± HT1B (E10±4)
OX (H17±3) ± OX1B (E12±21)Continuity
E2 (H17±4) ± E2 (E13±28)
y
Standard (Check for short): (Bank1 Sensor2)
Symbols (Terminal No.)Specified condition
HT (H17±1) or HT1B (E10±4) ± Body groundNo continuityOX (H17±3) or OX1B (E12±21) ± Body groundNo continuity
NG REPAIR OR REPLACE HARNESS OR
CONNECTOR
OK

A66053
Engine Room R/B No.4
EFI Relay



A79070
Engine Room R/B No.4
EFI No.2 Fuse 1
2
A79114
OX+B
E2 HT
Heated Oxygen Sensor Connector Wire Harness Side
H7
OX+B
E2 HT
Heated Oxygen Sensor Connector Wire Harness Side
H17
A73939
± DIAGNOSTICSSFI SYSTEM (1ZZ±FE/3ZZ±FE)
05±51
AVENSIS REPAIR MANUAL (RM1018E)
7 CHECK HARNESS AND CONNECTOR(EFI RELAY ± HEATED OXYGEN SENSOR)
(a) Remove the EFI relay from the engine room R/BNo.4.
(b) Remove the EFI No.2 fuse from the engine room R/B
No.4.
(c) Disconnect the heated oxygen sensor connector.
(d) Check for continuity between the wire harness side con-
nectors.
Standard (Check for open):
Symbols (Terminal No.)Specified condition
EFI relay (3) ± EFI No.2 fuse (1)Continuity
Standard (Check for short):
Symbols (Terminal No.)Specified condition
EFI relay (3) or EFI No.2 fuse (1) ± Body groundNo continuity
Standard (Check for open): (Bank1 Sensor1)
Symbols (Terminal No.)Specified condition
EFI No.2 fuse (2) ± +B (H7±2)Continuity
Standard (Check for short): (Bank1 Sensor1)
Symbols (Terminal No.)Specified condition
EFI No.2 fuse (2) or +B (H7±2) ± Body groundNo continuity
Standard (Check for open): (Bank1 Sensor2)
Symbols (Terminal No.)Specified condition
EFI No.2 fuse (2) ± +B (H17±2)Continuity
Standard (Check for short): (Bank1 Sensor2)
Symbols (Terminal No.)Specified condition
EFI No.2 fuse (2) or +B (H17±2) ± Body groundNo continuity
NG REPAIR OR REPLACE HARNESS OR
CONNECTOR
OK

05±52
±
DIAGNOSTICS SFI SYSTEM(1ZZ±FE/3ZZ±FE)
AVENSIS REPAIR MANUAL (RM1018E)
8CHECK WHETHER MISFIRE IS OCCURRED OR NOT BY MONITORING DTC AND DATA LIST
NGPERFORM TROUBLESHOOTING FOR MISFIRE
(See page 05±5)
OK
9CHECK AIR INDUCTION SYSTEM
(a)Check for vacuum leaks in air induction system. NGREPAIR OR REPLACE AIR INDUCTION SYSTEM
OK
10CHECK FUEL PRESSURE (See page 11±5)
(a)Check the fuel pressure (high or low pressure). NGREPAIR OR REPLACE FUEL SYSTEM
OK
11INSPECT FUEL INJECTOR ASSY(INJECTION AND VOLUME) (See page 11±8)
NGREPLACE FUEL INJECTOR ASSY
OK
12CHECK FOR EXHAUST GAS LEAK
NGREPAIR OR REPLACE EXHAUST GAS LEAKAGE POINT
OK
REPLACE HEATED OXYGEN SENSOR
13PERFORM CONFIRMATION DRIVING PATTERN (See page 05±54)
GO

A58684
ECM
5V
VC
VTA
E2 Throttle Position
Sensor
± DIAGNOSTICSSFI SYSTEM (1ZZ±FE/3ZZ±FE)
05±39
AVENSIS REPAIR MANUAL (RM1018E)
DTC P0120 THROTTLE PEDAL POSITION
SENSOR/SWITCH ºAº CIRCUIT
MALFUNCTION
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 VTA of the ECM. The voltage ap-
plied to terminal VTA 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 VTA, uses them as one of the conditions for decid-
ing the air±fuel ratio correction, power increase correction and
fuel±cut control etc.
DTC No.DTC Detecting ConditionTrouble Area
P0120
Condition (a) or (b) continues for more than 5 sec.
(a) VTA is less than 0.1 V
(b) VTA is greater than 4.9 V
Open or short in throttle position sensor circuit

Throttle position sensor

ECM
HINT:
After confirming DTC ºP0120º, use the hand±held tester to confirm the throttle valve opening percentage.
Throttle valve opening position expressed as percentageTrouble AreaThrottle valve fully closedThrottle valve fully openTrouble Area
0 %0 %VC circuit open
VTA circuit open or short
Approx. 100 %Approx. 100 %E2 circuit open
05B3S±02

A79108
VCECM
VTA
E2 L±W R±W
BR T2
Throttle Position Sensor
1
3
218
E13
21
E13
28
E13 VC
E2 VTA5V
E1 05±40
± DIAGNOSTICSSFI SYSTEM (1ZZ±FE/3ZZ±FE)
AVENSIS REPAIR MANUAL (RM1018E)
WIRING DIAGRAM
INSPECTION PROCEDURE
HINT:

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.

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.