2005 TOYOTA AVENSIS Circuit

A73819A±A SectionAirSolid Electrolyte
(Zirconia Element)
Platinum
Electrode Heater
Exhaust Gas
Cover Element
A
A
ECM Monitored
A/F Sensor Voltage
Air±Fuel Ratio
± DIAGNOSTICSSFI SYSTEM (1AZ±FE)
05±249
AVENSIS REPAIR MANUAL (RM1018E)
DTC P2255/28 OXYGEN SENSOR REFERENCE GROUND
CIRCUIT LOW (FOR A/F SENSOR)(BANK 2
SENSOR 1)
DTC P2256/28 OXYGEN SENSOR REFERENCE GROUND
CIRCUIT HIGH (FOR A/F SENSOR)(BANK 2
SENSOR 1)
CIRCUIT DESCRIPTION
HINT:
This DTC is recorded when A/F sensor has a malfunction, although the caption is healed oxygen sensor.
The air±fuel ratio sensor are 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 of 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 A/F sensor has the characteristic that it provides output voltage* being approximately proportional to
the existing air±fuel ratio. The A/F sensor output voltage* is used to provide feedback for the ECM to control
the air±fuel ratio.
By the A/F sensor output, the ECM can determine the deviation amount from the stoichiometric air±fuel ratio
and control the proper injection time immediately. If the A/F sensor is out of order, ECM is unable to perform
the accurate air±fuel ratio control.
The A/F sensor is equipped with 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), the current flows to the
heater to heat the sensor for the accurate oxygen concentration detection.
*: The voltage value changes at the inside of the ECM only.

05±250
± DIAGNOSTICSSFI SYSTEM (1AZ±FE)
AVENSIS REPAIR MANUAL (RM1018E)DTC No.
DTC Detecting ConditionTrouble Area
A/F sensor circuit (bank 1 sensor 1)HINT : Main trouble area

Open or short in A/F sensor circuit
P2237/21
P2240/28
Conditions (a) and (b) continue for 5.0 sec. or more :
(a) AF+ less than 0.5 V
(b) AF+ greater than 4.5 V
Open or short in A/F sensor circuit

A/F sensor

A/F sensor heater
Conditions (a) and (b) continue for 5.0 sec. or more :
(a) (AF+) ± (AF±) less than 0.1 V
(b) (AF+) ± (AF±) greater than 0.8 V
A/F sensor heater

A/F sensor heater relay

A/F sensor heater and relay circuit

ECM
A/F sensor circuit low (bank 1 sensor 1)HINT : Main trouble area

Open in A/F sensor circuit
P2238/21
P2241/28Condition (a) continues for 5.0 sec. or more :
(a) AF+ less than 0.5 V
Open or short in A/F sensor circuit

A/F sensor

A/F sensor heater
Condition (a) continues for 5.0 sec. or more :
(a) (AF+) ± (AF±) less than 0.1 V
A/F sensor heater

A/F sensor heater relay

A/F sensor heater and relay circuit

ECM
A/F sensor circuit high (bank 1 sensor 1)HINT : Main trouble area

Short in A/F sensor circuit
P2239/21
P2242/28Condition (a) continue for 5.0 sec. or more :
(a) AF+ greater than 4.5 V
Open or short in A/F sensor circuit

A/F sensor

A/F sensor heater
Condition (a) continue for 5.0 sec. or more :
(a) (AF+) ± (AF±) greater than 0.8 V
A/F sensor heater

A/F sensor heater relay

A/F sensor heater and relay circuit

ECM
P2251/21
P2254/28Conditions (a) and (b) continue for 5.0 sec. or more :
(a) AF± less than 0.5 V
(b) AF± greater than 4.5 V
Open or short in A/F sensor circuit

A/F sensor

A/F sensor heaterP2252/21
P2255/28Condition (a) continue for 5.0 sec. or more :
(a) AF± less than 0.5 V
A/F sensor heater

A/F sensor heater relay


A/F sensor heater and relay circuitP2253/21
P2256/28Condition (a) continue for 5.0 sec. or more :
(b) AF± greater than 4.5 V
A/F sensor heater and relay circuit

ECM
HINT:

   
       means malfunction related
to bank 1 A/F sensor circuit.

         
means malfunction related
to bank 2 A/F sensor circuit.

Bank 1 refers to the bank that includes cylinder No. 1.

Bank 2 refers to the bank that includes cylinder No. 2.

+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)
± DIAGNOSTICSSFI SYSTEM (1AZ±FE)
05±253
AVENSIS REPAIR MANUAL (RM1018E)
The following procedure of A/F CONTROL enables the technician to check and graph voltage output 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 DTC   
        is displayed, check bank 1
sensor 1 circuit.

If DTC         
 is displayed, check bank 2
sensor 1 circuit.

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 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.

±
DIAGNOSTICS SFI SYSTEM(1AZ±FE)
05±247
AVENSIS REPAIR MANUAL (RM1018E)
DTCP0606/89ECM/PCM PROCESSOR
CIRCUIT DESCRIPTION
DTC No.DTC Detection ConditionTrouble Area
P0606/89ECM inside error
ECM
INSPECTION PROCEDURE
HINT:
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 determi\
ning whether the vehicle was running
or stopped, the engine was warmed up or not, the air±fuel ratio was lea\
n or rich, etc. at the time of the mal-
function.
CHECK AND REPLACE ECM (See page 01±32)
05C75±01

A58697
Intake Air
Chamber
Throttle Valve
To Cylinder
ISC Valve
Valve
ECM
Signal From
Air
Cleaner
From
Terminal 2 of
EFI No.1 Fuse
(See Page 05±257)
A79101
2 +B DUTY1
GND 3
I10
ISC Valve
G±R10
E12 RSDECM
B±R 12
EA1 B±R
W±B7
E12 E1
BR
EF
±
DIAGNOSTICS SFI SYSTEM (1AZ±FE)
05±243
AVENSIS REPAIR MANUAL (RM1018E)
DTC P0511/33 IDLE AIR CONTROL CIRCUIT
CIRCUIT DESCRIPTION
The rotary solenoid type idle speed control (ISC) valve is lo-
cated under the throttle body and intake air bypassing the
throttle valve is directed to the idle speed control (ISC) valve
through the passage.
In this way the intake air volume bypassing the throttle valve is
regulated, controls the engine speed.
The ECM operates the idle speed control (ISC) valve only to
perform idle±up and provide feedback for the target idling
speed.
DTC No.DTC Detecting ConditionTrouble Area
P0511/33Idle speed continues to vary greatly from target speed
(1 trip detection logic)

Open or short in idle speed control (ISC) valve circuit

Idle speed control (ISC) valve is stuck or closed

A/C switch circuit

Air induction system

ECM
WIRING DIAGRAM
INSPECTION PROCEDURE
HINT:
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 determi\
ning whether the vehicle was running
or stopped, the engine was warmed up or not, the air±fuel ratio was lea\
n or rich, etc. at the time of the mal-
function.
05C74±01

A65745
RSD
E12ECM Connector
E1
A65745
RSD
E12
ECM Connector
E1
123
A66264
DUTY ISC valve Connector
Wire Harness SideGND
I10
A65745
RSD (+)
E12
ECM Connector
E1 (±)
±
DIAGNOSTICS SFI SYSTEM(1AZ±FE)
05±245
AVENSIS REPAIR MANUAL (RM1018E)
3CHECK HARNESS AND CONNECTOR(RSD CIRCUIT)
(a)Disconnect the ISC valve connector.
(b)Disconnect the E12 ECM connector.
(c)Check for continuity between the wire harness side con-
nectors.
Standard (Check for open):
Symbols (Terminal No.)Specified condition
DUTY (I10±1) ± RSD (E12±10)ContinuityGND (I10±3) ± E1 (E12±7)Continuity
Standard (Check for short):
Symbols (Terminal No.)Specified condition
DUTY (I10±1)or RSD (E12±10) ± Body groundrNo continuity
NGREPAIR OR REPLACE HARNESS OR CONNECTOR
OK
4INSPECT THLOTTLE BODY IDLE SPEED CONTROL VALVE ASSY (See page 10±18)
NG REPLACE THLOTTLE BODY IDLE SPEED CONTROL VALVE ASSY
OK
CHECK AND REPLACE ECM (See page 01±32)
When not using hand±held tester:
1 INSPECT ECM
(a) Disconnect the E12 ECM connector.
(b) Turn the ignition switch ON.
(c) Measure the voltage between the terminals of the E4 ECM connector.
Standard:
Symbols (Terminal No.)Specified condition
RSD (E12±10) ± E1 (E12±7)9 to 14 V
OK Go to step 3
NG

A79413
From
Speed SensorSkid
Control
ECU4±Pulse
Combination
Meter4±Pulse
ECM 05±240
± DIAGNOSTICSSFI SYSTEM (1AZ±FE)
AVENSIS REPAIR MANUAL (RM1018E)
DTC P0500/42 VEHICLE SPEED SENSOR ºAº
CIRCUIT DESCRIPTION
The speed sensor for skid control ECU detects the wheel speed and sends the appropriate signals to the
skid control ECU.
The skid control ECU converts these signals into a 4±pulse signal and outputs it to the combination meter.
After this signal is converted into a more precise rectangular waveform by the waveform shaping circuit in-
side the combination meter, it is then transmitted to the ECM. The ECM determines the vehicle speed based
on the frequency of these pulse signals.
DTC No.DTC Detection ConditionTrouble Area
P0500/42
During the vehicle is being driven, no vehicle speed sensor
signal to the ECM
(2 trip detection logic)

Open or short in speed sensor circuit

Speed sensor

Combination meter

ECM

Skid control ECU
05C73±01

A76866
Combination MeterECM
C11 V±W
SPD
17
V±W E10
J/C
18H
J10
(LHD) J20
H
(RHD) H
J10
(LHD) J20
H
(RHD)
±
DIAGNOSTICS SFI SYSTEM(1AZ±FE)
05±241
AVENSIS REPAIR MANUAL (RM1018E)
WIRING DIAGRAM
INSPECTION PROCEDURE
HINT:
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 determi\
ning whether the vehicle was running
or stopped, the engine was warmed up or not, the air±fuel ratio was lea\
n or rich, etc. at the time of the mal-
function.
1CHECK OPERATION OF SPEEDOMETER
(a)Drive the vehicle and check that the operation of the speedometer in the\
combination meter is normal.
HINT:
The vehicle speed sensor is operating normally if the speedometer display i\
s normal.
NGCHECK SPEEDOMETER CIRCUIT(See page 05±1500)
OK