2005 TOYOTA AVENSIS fuel

+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±61
AVENSIS REPAIR MANUAL (RM1018E)
The following procedure of A/F CONTROL enable the technician to check and graph volatge 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.
NOTICE:
If the vehicle is lack of fuel, the air±fuel ratio becomes LEAN and DTC P0133 will be set, and the CHK
ENG then comes on.
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.

A high heated oxygen sensor (sensor 1) voltage (0.55 V or more) could 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 be caused by a lean air fuel mix-
ture. Check for conditions that would cause the engine to run lean.

±
DIAGNOSTICS SFI SYSTEM(1ZZ±FE/3ZZ±FE)
05±63
AVENSIS REPAIR MANUAL (RM1018E)
5CHECK FUSE(EFI No.2) (See page 05±45)
NGCHECK FOR SHORT IN ALL HARNESS AND
COMPONENTS CONNECTED FUSE
OK
6CHECK HARNESS AND CONNECTOR(HEATED OXYGEN SENSOR ± ECM) (See page 05±45)
NGREPAIR OR REPLACE HARNESS OR CONNECTOR
OK
7CHECK HARNESS AND CONNECTOR(EFI RELAY ± HEATED OXYGEN SENSOR) (See page 05±45)
NGREPAIR OR REPLACE HARNESS OR
CONNECTOR
OK
8CHECK AIR INDUCTION SYSTEM
(a)Check for vacuum leaks in air induction system. NGREPAIR OR REPLACE AIR INDUCTION SYSTEM
OK
9CHECK FUEL PRESSURE (See page 11±5)
(a)Check the fuel pressure (high or low pressure). NGREPAIR OR REPLACE FUEL SYSTEM
OK
10INSPECT FUEL INJECTOR ASSY(INJECTION AND VOLUME) (See page 11±8)
NGREPLACE HEATED OXYGEN SENSOR
OK
REPLACE HEATED OXYGEN SENSOR
11PERFORM CONFIRMATION DRIVING PATTERN (See page 05±54)
GO

05±54
±
DIAGNOSTICS SFI SYSTEM(1ZZ±FE/3ZZ±FE)
AVENSIS REPAIR MANUAL (RM1018E)
DTCP0130OXYGEN SENSOR CIRCUIT MALFUNCTION (BANK 1 SENSOR 1)
DTCP0136OXYGEN SENSOR CIRCUIT MALFUNCTION (BANK 1 SENSOR 2)
CIRCUIT DESCRIPTION
Refer to DTC P0125 on page 05±45.
DTC NoDTC Detecting ConditionTrouble Area
P0130Voltage output of heated oxygen sensor remains between
0.40 V and 0.55 V during idling after the engine is warmed up

Open or short in heated oxygen sensor circuit

Heated oxygen sensor

Air induction system

Fuel pressure

Injector

ECM
P0136
Voltage output of heated oxygen sensor remains 0.4 V or more
or 0.5 V or less when vehicle is driven at 30 km/h (19 mph) or
more after the engine is warmed up (2 trip detection loginc)
Open or short in heated oxygen sensor circuit

Heated Oxygen sensor
HINT:

 


 \f
\f















\b


\f

 
\f


 
 

\f
 \f
\f


WIRING DIAGRAM
Refer to DTC P0125 on page 05±45.
05B3V±02

+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) 05±56
± DIAGNOSTICSSFI SYSTEM (1ZZ±FE/3ZZ±FE)
AVENSIS REPAIR MANUAL (RM1018E)
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.
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.
NOTICE:
If the vehicle has low fuel, the air±fuel ratio becomes LEAN and heated oxygen sensor DTCs will be
recorded, and the CHK ENG lamp then comes on.
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.

A high heated oxygen sensor (sensor 1) voltage (0.55 V or more) could 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 be caused by a lean air fuel mix-
ture. Check for conditions that would cause the engine to run lean.

05±58
±
DIAGNOSTICS SFI SYSTEM(1ZZ±FE/3ZZ±FE)
AVENSIS REPAIR MANUAL (RM1018E)
5CHECK FUSE(EFI No.2) (See page 05±45)
NGCHECK FOR SHORT IN ALL HARNESS AND COMPONENTS CONNECTED FUSE
OK
6CHECK HARNESS AND CONNECTOR(HEATED OXYGEN SENSOR ± ECM) (See page 05±45)
NGREPAIR OR REPLACE HARNESS OR CONNECTOR
OK
7CHECK HARNESS AND CONNECTOR(EFI RELAY ± HEATED OXYGEN SENSOR) (See page 05±45)
NGREPAIR OR REPLACE HARNESS OR
CONNECTOR
OK
8CHECK AIR INDUCTION SYSTEM
(a)Check for vacuum leaks in air induction system. NGREPAIR OR REPLACE AIR INDUCTION SYSTEM
OK
9CHECK FUEL PRESSURE (See page 11±5)
(a) Check the fuel pressure (high or low pressure). NG REPAIR OR REPLACE FUEL SYSTEM
OK
10INSPECT FUEL INJECTOR ASSY(INJECTION AND VOLUME) (See page 11±8)
NG REPLACE FUEL INJECTOR ASSY
OK
REPLACE HEATED OXYGEN SENSOR
11 PERFORM CONFIRMATION DRIVING PATTERN
GO

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 (1ZZ±FE/3ZZ±FE)
05±45
AVENSIS REPAIR MANUAL (RM1018E)
DTC P0125 INSUFFICIENT COOLANT TEMP. FOR
CLOSED LOOP FUEL CONTROL
CIRCUIT DESCRIPTION
The heated oxygen sensor is the planar type. Compared to the conventional type, the sensor element and
the heater portions have a narrower overall. The heater can directly conduct its heat to the zirconia element
via the alumina, it helps to accerate the sensor activation.
To obtain a high purification rate for the CO, HC and NOx components of the exhaust gas, a three ± way
catalytic 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 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 0.45V). 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 abnomal 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 Detecting ConditionTrouble Area
P0125
After engine is warmed up, heated oxygen sensor output* does
not change when conditions (a), (b), (c) and (d) continue for at
least 1.5 min:
*: Output value changes at inside of the ECM only
(a) Engine speed: 1,400 rpm or more
(b) Vehicle speed: 40 to 100 km/h (25 to 62 mph)
(c) Throttle valve is not fully closed
(d) 180 sec. or more after starting engine
Open or short in heated oxygen sensor circuit

Heated oxygen sensor

Air induction system

Fuel pressure

Injector

Gas leakage in exhaust system

ECM
05C69±01

+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