2005 TOYOTA AVENSIS fuel

A79082
53G±Y
L±B E9 10
4
5 W±B
BR F25
Fuel Pump ECM
B±W 12
FC
C8
Circuit
Opening Relay
From
Terminal 3 of
EFI Relay
(See Page 05±124)
G±Y
B±W
B±W
IB1 10 IC3
6
±
DIAGNOSTICS SFI SYSTEM(1ZZ±FE/3ZZ±FE)
05±131
AVENSIS REPAIR MANUAL (RM1018E)
FUEL PUMP CONTROL CIRCUIT
CIRCUIT DESCRIPTION
In the diagram below, when the engine is cranked, current flows from terminal ST of the igni\
tion switch to
the starter relay coil and also current flows to terminal STA of the ECM (STA signal).
When the STA signal and NE signal are input to the ECM, Tr is turned ON, current flows to the coil of the
circuit opening relay, the relay switches on, power is supplied to the fuel pump and the fuel p\
ump operates.
While the NE signal is generated (engine running), the ECM keeps Tr ON (circuit opening relay ON) and the
fuel pump also keeps operating.
WIRING DIAGRAM
INSPECTION PROCEDURE
1PERFORM ACTIVE TEST USING HAND±HELD TESTER(OPERATION OF CIRCUIT
OPENING RELAY)
(a)Turn the ignition switch ON.
(b)Select the item ºDIAGNOSIS / OBD/MOBD / ACTIVE TEST / FUEL PUMP / SPD\
º.
(c)Perform the active test with the engine stopped.
Result: The circuit opening relay operates.
OKPROCEED TO NEXT CIRCUIT INSPECTIONSHOWN ON PROBLEM SYMPTOMS TABLE
NG
2CHECK FOR ECM POWER SOURCE CIRCUIT(See page 05±124)
NG REPAIR OR REPLACE POWER SOURCE CIRCUIT
OK
05C6H±01

A66053
Engine Room R/B No.4EFI Relay
123
5
A79099
Wire Harness Side
C8
Circuit Opening Relay Connector
A65748
E9
MRELFC
±
DIAGNOSTICS SFI SYSTEM(1ZZ±FE/3ZZ±FE)
05±133
AVENSIS REPAIR MANUAL (RM1018E)
5CHECK HARNESS AND CONNECTOR(EFI RELAY ± CIRCUIT OPENING RELAY,
CIRCUIT OPENING RELAY ± ECM)
(a)Remove the EFI relay from the engine room R/B No.4.
(b)Remove the circuit opening relay.
(c)Disconnect the E9 ECM connector.
(d)Check for continuity between the wire harness side con-
nectors.
Standard (Check for open):
Symbols (Terminal No.)Specified condition
EFI relay (3) ± Circuit opening relay (C8±1)
Circuit opening relay (C8±2) ± FC (E9±10)Continuity
EFI relay (1) ± MREL (E9±8)
y
Standard (Check for short):
Symbols (Terminal No.)Specified condition
EFI relay (3) or Circuit opening relay (C8±1) ± Body ground
Circuit opening relay (C8±2) or FC (E9±10) ± Body groundNo continuity
EFI relay (1) or MREL (E9±8) ± Body ground
y
NGREPAIR OR REPLACE HARNESS OR CONNECTOR
OK
CHECK AND REPLACE ECM (See page 01±32)
6INSPECT FUEL PUMP ASSY (See page 11±8)
NG REPAIR OR REPLACE FUEL PUMP ASSY
OK

123
5
A79099
Wire Harness Side
C8
Circuit Opening Relay Connector
A66276
Fuel Pump Connector
Wire Harness Side
F25
05±134
±
DIAGNOSTICS SFI SYSTEM(1ZZ±FE/3ZZ±FE)
AVENSIS REPAIR MANUAL (RM1018E)
7CHECK HARNESS AND CONNECTOR(CIRCUIT OPENING RELAY ± FUEL PUMP, FUEL PUMP ± BODY GROUND)
(a)Remove the circuit opening relay.
(b)Disconnect the fuel pump connector.
(c)Check for continuity between the wire harness side con-
nectors.
Standard (Check for open):
Symbols (Terminal No.)Specified condition
Circuit opening relay (C8±3) ± Fuel pump (F24±4)ContinuityFuel pump (F25±5) ± Body groundContinuity
Standard (Check for short):
Symbols (Terminal No.)Specified condition
Circuit opening relay (C8±3) or Fuel pump (F24±4) ±
Body groundNo continuity
NGREPAIR OR REPLACE HARNESS ORCONNECTOR
OK
CHECK AND REPLACE ECM (See page 01±32)

\bA79115
Reference (Bank 1 Sensor 2 System Drawing)Heated Oxygen Sensor
EFI Relay
Heater
SensorOX1B HT1BECM
From
Battery EFI Fuse
O1B±
MREL
EFI No.2 Fuse
05±218
±
DIAGNOSTICS SFI SYSTEM(1AZ±FE)
AVENSIS REPAIR MANUAL (RM1018E)
DTCP0141/27OXYGEN SENSOR HEATER CIRCUIT MALFUNCTION (BANK 1 SENSOR 2)
DTCP0161/29OXYGEN SENSOR HEATER CIRCUIT (BANK 2 SENSOR 2)
CIRCUIT DESCRIPTION
Refer to DTC P0136/27 on page 05±211.
HINT:
The ECM provides a pulse width modulated control circuit to adjust current \
through the heater. The heated
oxygen sensor heater circuit uses a relay on the B+ side of the circuit.
DTC No.DTC Detection ConditionTrouble Area
P0141/27
Heated current is 0.2 A or less when heater operates
(1 trip detection logic)
Open or short in heater circuit of heated oxygen sensor

Heated oxygen sensor heater
P0141/27
P0161/29When heater operates, heated current exceeds 2 A
(1 trip detection logic)
yg

EFI relay

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

Sensor 2 refers to the sensor farthest away from the engine assembly.
WIRING DIAGRAM
Refer to DTC P0136/27 on page 05±211.
INSPECTION PROCEDURE
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

\f \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.
05C6Y±01

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

+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.

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

A12544
VCECM
VTA1
E2 L±W R±W
BR T2
Throttle Position Sensor
1
3
218
E13
21
E13
28
E13 VC
E2 VTA5V
E1
± DIAGNOSTICSSFI SYSTEM (1AZ±FE)
05±205
AVENSIS REPAIR MANUAL (RM1018E)Throttle valve opening position expressed as percentage
Trouble 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
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.