2005 TOYOTA AVENSIS sensor

A80452
PCR1E
13
ECM Connector
E
12PCR2
E2VCS
E2S
VC
A84808
E2
F
16
Wire Harness Side:
Front View
VCS
PRE2S
VC
Fuel Pressure Sensor Connector
PR2
−
DIAGNOSTICS ECD SYSTEM (1CD −FTV)(From September, 2003)
05 −319
AVENSIS Supplement (RM 1045E)
2 CHECK IF DTCS OUTPUT RECUR(FUEL PRESSURE SENSOR DTCS)
(a) Connect the hand −held tester to the DLC3.
(b) Turn the ignition switch to ON and turn the hand −held tester ON.
(c) Select the item ”DIAGNOSIS / OBD/MOBD / DTC INFO / CLEAR CODES”.
(d) Clear the DTCs.
(e) Let the engine idle for 60 seconds, and repeat quick engine RPM acceleration (to 2,500 rpm) for 30 seconds.
(f) Select the item ”DIAGNOSIS / OBD/MOBD / DTC INFO / CURRENT CODES”.
(g) Read DTCs.
Result:
Display (DTC output)Proceed to
P0087, P0 190, P0 192 and/or P0 193A
No outputB
B CHECK FOR INTERMITTENT PROBLEMS
(See page 05 −270)
A
REPLACE ECM (See page 10− 29)
3 CHECK HARNESS AND CONNECTOR(FUEL PRESSURE SENSOR − ECM)
(a) Disconnect the E 12 and E 13 ECM connectors.
(b) Disconnect the F 16 fuel pressure sensor connector.
(c) Check the resistance between the wire harness side con-
nectors.
Standard (Check for open):
Tester ConnectionSpecified Condition
PCR1(E 13− 26) −PR (F 16− 5)
PCR2 (E 13− 33) −PR2 (F 16− 2)
VCS (E 12− 2) −VCS (F 16−1 )Below1
VC (E 13−1 8)−VC (F 16− 6)Below 1

E2 (E 13− 28) −E2 (F 16− 4)
E2S (E 12−1 )− E2S (F 16− 3)
Standard (Check for short):
Tester ConnectionSpecified Condition
PCR 1(E 13− 26) or PR (F 16− 5) −Body ground
PCR2 (E 13− 33) or PR2 (F 16 − 2) −Body ground
VCS (E 12− 2) or VCS (F 16−1 )− Body ground10k
orhigherVC (E 13−1 8) or VC (F 16− 6) −Body ground10k
or higher
E2 (E 13− 28) or E2 (F 16− 4) −Body ground
E2S (E 12−1 ) or E2S (F 16− 3) −Body ground
(d) Reconnect the ECM connectors.
(e) Reconnect the fuel pressure sensor connector.

05−320
−
DIAGNOSTICS ECD SYSTEM (1CD −FTV)(From September, 2003)
AVENSIS Supplement (RM 1045E)
NG REPAIR OR REPLACE HARNESS OR
CONNECTOR
OK
REPLACE COMMON RAIL ASSY (FUEL PRESSURE SENSOR) (See page 11− 67)

A91218
ECM Monitor ed
A/F Sens or Voltage
Air−Fuel Ratio
Solid Electrolyte
(Zirconia Element)
Cover Atmosphere
Exhaust Gas Flange
Platinum Electrode
Coating (Ceramic)
Heater
−
DIAGNOSTICS ECD SYSTEM (1CD−FTV)(From September, 2003)
05 −305
AVENSIS Supplement (RM1045E)
DTC P003 1 OXYGEN (A/F) SENSOR HEATER CONTROL
CIRCUIT LOW (BANK 1 SENSOR 1)
HINT:
S For more information on the A/F sensor and TOYOTA D −CAT (*1), see page 05 −255.
S If P0031 is present, refer to the diagnostic trouble codes (DTCs) table for the TOYOTA D −CAT on page
05 −255.
SThis DTC is related to the A/F sensor, although the caption is the oxygen sensor.
*1: Diesel Clean Advanced Technology.
CIRCUIT DESCRIPTION
The A/F sensor has the characteristic that it provides output voltage which is proportional to the existing air −
fuel ratio. The A/F sensor output voltage (*2) is used to provide the ECM with feedback to control the air −fuel
ratio.
The A/F sensor is located after the DPNR (*3) catalytic converter. This sensor has been developed based
on structure and technology of a sensor that is being used for gasoline engines. Its cover portion of the sen-
sor has been changed for application of use to the diesel engine with TOYOTA D −CAT in order to eliminate
influence of the sensor temperature and particulate matter (PM).
In order to reduce both PM and nitrogen oxides (NOx), the ECM adjusts the air −fuel ratio to slightly RICH
(but it is LEAN compared with a stoichiometric air −fuel ratio) with signals from the A/F sensor, if needed.
When the ECM exercises DPNR catalyst regeneration by adding fuel using the exhaust fuel addition injector,
the air −fuel ratio is also properly adjusted through the sensor.
*2: The voltage value changes inside the ECM only.
*3: Diesel Particulate −NOx Reduction system.
05I7J −01

B62793
Reference:
A/F Sensor A/F Sensor
Heater Relay
Heater
Sensor
AF2+ HAF2
Duty
Control ECM
From
Battery
A/F Fuse
AF2−
MREL 05−306
− DIAGNOSTICSECD SYSTEM (1CD−FTV)(From September, 2003)
AVENSIS Supplement (RM1045E)
HINT:
The ECM provides a pulse width modulated control circuit to adjust current through the heater. The A/F sen-
sor heater circuit uses a relay on the B+ side of the circuit.
DTC No.DTC Detection ConditionTrouble Area
P0031Heated current is 1.5 A or less when the heater operates
(1 trip detection logic)
SOpen in A/F sensor heater circuit
SA/F sensor heater
SA/F sensor heater relay
SECM
MONITOR DESCRIPTION
The inner surface of the A/F sensor element is exposed to outside air. The outer surface of the sensor ele-
ment is exposed to exhaust gases. The sensor element is made of platinum coated zirconia and includes
an integrated heating element. The zirconia element generates small voltage when there is a large differ-
ence in the oxygen concentrations of the exhaust and the outside air. The platinum coating amplifies the
voltage generation. When heated, the sensor becomes very efficient. If the temperature of the exhaust is
low, the sensor will not generate useful voltage signals without supplemental heating. The ECM regulates
the supplemental heating using a duty−cycle approach to regulate the average current in the heater ele-
ment. If the heater current is out of the normal range, the sensor’s output signals will be inaccurate and the
ECM can not regulate the air−fuel ratio properly. When the heater current is out of the normal operating
range, the ECM interprets this as a malfunction and sets a DTC.

A91217
MREL
W
GRE9
IE5
B
Battery FL MAINAF2+ 8
1 126
Engine Room
R/B No. 1ECM
6AGR
3AF2−
HAF2
E1 E1035
E1034 1
IP1 (RHD)(LHD) 1
2
W
1
2
1
11B
W
2
1
325
3
W−B
A
A
A
W−B(RHD)
(LHD)W−B
A
IP IKEI J17
J/C
J15
J/C B−R
Fuse Block
A/F AM1 No. 1 140A ALT
A35
A/F Sensor
Relay B−R
W
(*1)W
(*2)
IH2 1
B−W
(*1)A34A34 A34 A34A34
A34
A34
A34 2
2 11 3
44
3
+B AF+
AF−
HT B
(*1)
(*2)
(*1)
(*2) (*2)
B(*1)
(*3)W(*1)
W
(*2) IH2 3
IH2 4
B
(*1)BR
(*1)
A34
A/F sensor BR
E12
E127 5
IK1 3
L−RL−R
(*2)
L−R
(*1) IH2
2R
(*1)
BR J/C J13
J12 D
E
BR
*1: w/ Headlight Beam Level Control
*2: w/o Headlight Beam Level Control
*3: Shielded
− DIAGNOSTICSECD SYSTEM (1CD−FTV)(From September, 2003)
05−307
AVENSIS Supplement (RM1045E)
WIRING DIAGRAM

A87894
AF−AF+
A34
Front View Component Side
(w/ Headlight Beam Level Control):
1 2
3 4
HT
+B
A/F Sensor
Connector
A87894
AF− AF+
A34
Front View
HT +B
1 2
3 4 Component Side
(w/o Headlight Beam Level Control):
A/F Sensor
Connector
B16200
05−308
− DIAGNOSTICSECD SYSTEM (1CD−FTV)(From September, 2003)
AVENSIS Supplement (RM1045E)
INSPECTION PROCEDURE
1INSPECT AIR FUEL RATIO SENSOR(RESISTANCE)
(a) Disconnect the A34 A/F sensor connector.
(b) Measure the resistance between the terminals of the A/F
sensor.
Resistance (w/ Headlight beam level control):
Tester ConnectionSpecified Condition
HT (1)−+B (2)0.86 to 1.1
at 20_C (68_F)
Resistance (w/o Headlight beam level control):
Tester ConnectionSpecified Condition
HT (2)−+B (1)0.86 to 1.1
at 20_C (68_F)
(c) Reconnect the A/F sensor connector.
NG REPLACE AIR FUEL RATIO SENSOR
OK
2 INSPECT AIR FUEL RATIO SENSOR HEATER RELAY
(a) Remove the A/F sensor heater relay.
(b) Inspect the A/F sensor heater relay.
Standard:
Tester ConnectionSpecified Condition
1−2Continuity
No continuity
3−5Continuity
(Apply battery voltage to terminals 1 and 2)
(c) Reinstall the A/F sensor heater relay.
NG REPLACE AIR FUEL RATIO SENSOR HEATER
RELAY
OK

A81086
E1 (−)
E12
HAF2 (+)
ECM Connector
−
DIAGNOSTICS ECD SYSTEM (1CD−FTV)(From September, 2003)
05 −309
AVENSIS Supplement (RM1045E)
3 INSPECT ECM(A/F SENSOR HEATER VOLTAGE)
(a) Turn the ignition switch to ON.
(b) Measure the voltage between the applicable terminals of
the E12 ECM connector.
Standard:
Tester ConnectionSpecified Condition
HAF2 (E12 −5) − E1 (E12 −7)9to14V
OK REPLACE ECM (See page 10− 29)
NG

A90355
Wire Harness Side
(w/ Headlight Beam Level Control):
+B
HT
A34
Front View A/F Sensor Connector
A90355
Wire Harness Side
(w/o Headlight Beam Level Control):
+B
HT
A34
Front View A/F Sensor Connector
A81087
E12
HAF2 (+)
ECM Connector
A90544
Wire Harness Side:
A/F Sensor Heater RelayHAF2
05−310
− DIAGNOSTICSECD SYSTEM (1CD−FTV)(From September, 2003)
AVENSIS Supplement (RM1045E)
4 CHECK HARNESS AND CONNECTOR(A/F SENSOR−ECM, A/F SENSOR−A/F
SENSOR HEATER RELAY)
(a) Check the harness and the connectors between the ECM
and the A/F sensor.
(1) Disconnect the A34 A/F sensor connector.
(2) Disconnect the E12 ECM connector.
(3) Check the resistance between the wire harness
side connectors.
Standard (Check for open)
(w/ Headlight beam level control):
Tester ConnectionSpecified Condition
HT (A34−1)−HAF2 (E12−5)Below 1

Standard (Check for open)
(w/o Headlight beam level control):
Tester ConnectionSpecified Condition
HT (A34−2)−HAF2 (E12−5)Below 1

Standard (Check for short)
(w/ Headlight beam level control):
Tester ConnectionSpecified Condition
HT (A34−1) or HAF2 (E12−5)−Body ground10 k
or higher
Standard (Check for short)
(w/o Headlight beam level control):
Tester ConnectionSpecified Condition
HT (A34−2) or HAF2 (E12−5)−Body ground10 k
or higher
(4) Reconnect the A/F sensor connector.
(5) Reconnect the ECM connector.
(b) Check the harness and connectors between the A/F sen-
sor connector and the A/F sensor heater relay.
(1) Disconnect the A34 A/F sensor connector.
(2) Remove the A/F sensor heater relay from the en-
gine room R/B.
(3) Check the resistance between the wire harness
side connectors.
Standard (Check for open)
(w/ Headlight beam level control):
Tester ConnectionSpecified Condition
+B (A34−2)−A/F sensor heater relay (3)Below 1

Standard (Check for open)
(w/o Headlight beam level control):
Tester ConnectionSpecified Condition
+B (A34−1)−A/F sensor heater relay (3)Below 1

Standard (Check for short)
(w/ Headlight beam level control):
Tester ConnectionSpecified Condition
+B (A34−2) or A/F sensor heater relay (3)−Body ground10 k
or higher