check engine TOYOTA AVALON 2001 Service Repair Manual

DI-50
- DIAGNOSTICSENGINE
206 Author
: Date
:
2001 AVALON (RM808U)
3 Check output voltage of heated oxygen sensor.
PREPARATION:
(a) Connect the OBD II scan tool or TOYOTA hand-held tester to the DLC3.
(b) Warm up the engine to normal operating temperature.
CHECK:
Read the voltage output of the heated oxygen sensor when the engine is suddenly raced.
HINT:
Perform quick racing to 4,000 rpm 3 min. using the accelerator pedal.
OK:
Heated oxygen sensor output voltage: Alternates from 0.4 V or less to 0.6 V or more.
OK Check that each connector is properly con-
nected.
NG
Replace heated oxygen sensor.

A06104
ON
HTS
(+)
(-)
- DIAGNOSTICSENGINE
DI-51
207 Author
: Date
:
2001 AVALON (RM808U)
DTC P0141 Oxygen Sensor Heater Circuit Malfunction
(Bank 1 Sensor 2)
CIRCUIT DESCRIPTION
Refer to DTC P0125 on page DI-43.
DTC No.DTC Detecting ConditionTrouble Area
P0141
When heater operates, heater current exceeds 2.35 A (2 trip
detection logic)
Open or short in heater circuit of heated oxygen sensor
Htd htP0141Heater current of 0.2 A or less when heater operates (2 trip
detection logic)
Heated oxygen sensor heater

ECM
HINT:

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

Sensor 2 refers to the sensor farther away from the engine body.
WIRING DIAGRAM
Refer to DTC P0125 on page DI-43.
INSPECTION PROCEDURE
HINT:
Read freeze frame data using TOYOTA hand-held tester or OBD II scan tool. Because freeze frame records
the engine conditions when the 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.
1 Check voltage between terminal HTS of ECM connector and body ground.
PREPARATION:
(a) Remove the glove compartment (See page SF-82).
(b) Turn the ignition switch ON.
CHECK:
Measure the voltage between terminal HTS of the ECM con-
nector and body ground.
OK:
Voltage: 9 - 14 V
OK Check and replace ECM (See page IN-30).
NG
2 Check resistance of heated oxygen sensor heater (See page SF-81).
NG Replace heated oxygen sensor.
DI6T3-01

DI-52
- DIAGNOSTICSENGINE
208 Author
: Date
:
2001 AVALON (RM808U)
OK
Check and repair harness or connector between EFI main relay (Marking: EFI) and heated oxygen
sensor, and heated oxygen sensor and ECM (See page IN-30).

A11083
Fusible
Link Block
Battery FL
MainB-O
B-W
2
2
2
2
2
21
1
1
1
1
1L
R
Y
W
GE5
IG Switch
No.1
No.2
No.3
No.4
No.5
No.6
Injector
W-B
ED
5
6
21
311
2
3
4#10
#20
#30
#40
#50
#60
E01
E02ECM
112B
2G
AM2
41 B
F6F7
11J
67
IF1 1C
2CIG23
5
W-RE4
E4
E4
E4
E4
E4E5
W-B
B-W
B-W
B-W
B-W
B-W22
2
2C2F
7
7
W-R
4
1
B
Driver Side J/BEngine Room J/B
W-B
EB
G DDL J8
J/C
B-WB-W B-WB-W B-W
IG2 Relay
W-B
B-O2
- DIAGNOSTICSENGINE
DI-59
215 Author
: Date
:
2001 AVALON (RM808U)
HINT:
When the 2 or more codes for a misfiring cylinder are recorded repeatedly but no Random Misfire code is
recorded, it indicates that the misfires were detected and recorded at different times.
WIRING DIAGRAM
CONFIRMATION DRIVING PATTERN
(a) Connect the TOYOTA hand-held tester or OBD II scan tool.
(b) Record the DTC and the freeze frame data.
(c) Use the TOYOTA hand-held tester to set to the check mode (See page DI-3).
(d) Drive the vehicle several times with the engine speed, load and its surrounding range shown with the
ENGINE SPD, CALC LOAD in the freeze frame data or the MISFIRE RPM, MISFIRE LOAD in the data
list.
If you have no TOYOTA hand-held tester, turn the ignition switch OFF after the symptom is simulated the
first time. Then repeat the simulation process again.
HINT:
In order to memorize DTC of misfire, it is necessary to drive around MISFIRE RPM, MISFIRE LOAD in the
data list for the following period of time.
Engine SpeedTime
Idling3 minutes 30 seconds or more
1,000 rpm3 minutes or more
2,000 rpm1 minute 30 seconds or more
3,000 rpm1 minute or more

DI-60
- DIAGNOSTICSENGINE
216 Author
: Date
:
2001 AVALON (RM808U)
(e) Check whether there is misfire or not by monitoring DTC and the freeze frame data. After that, record
them.
(f) Turn the ignition switch OFF and wait at least 5 seconds.
INSPECTION PROCEDURE
HINT:

If is case that DTC besides misfire is memorized simultaneously, first perform the troubleshooting for
them.

Read freeze frame data using TOYOTA hand-held tester or OBD II scan tool. Because freeze frame
data records the engine conditions when the 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.

When the vehicle is brought to the workshop and the misfire is not occurred, misfire can be confirmed
by reproducing the condition or freeze frame data. Also, after finishing the repair, confirm that there
is no misfire. (See the confirmation driving pattern)

When either of SHORT FT #1, LONG FT #1, SHORT FT #2 or LONG FT #2 in the freeze frame data
is besides the range of ±20 %, there is a possibility that the air-fuel ratio is inclining either to ºrichº (-20
% or less) or ºleanº (+20 % or more).

When COOLANT TEMP in the freeze frame data is less than 80°C (176°F), there is a possibility or
misfire only during warming up.

In the case that misfire cannot be reproduced, the reason may be because of the driving with lack or
fuel, the use of improper fuel, a stain of ignition plug, and etc.
1 Check wire harness, connector and vacuum hose in engine room.
CHECK:
(a) Check the connection conditions of wire harness and connector.
(b) Check the disconnection, piping and break of vacuum hose.
NG Repair or replace, then confirm that there is no
misfire (See the confirmation driving pattern).
OK

B02101B04941
A06102
1.1 mm
A02024
ON
#10
#20 #40
(+)
#50 #60#30
(-)
- DIAGNOSTICSENGINE
DI-61
217 Author
: Date
:
2001 AVALON (RM808U)
2 Check spark plug and spark of misfiring cylinder.
PREPARATION:
(a) Remove the ignition coil (See page IG-5).
(b) Remove the spark plug.
CHECK:
(a) Check spark plug type.
(b) Check the electrode for carbon deposits.
(c) Check electrode gap.
OK:
(a) Iridium-tipped spark plug
Recommended spark plug:
DENSO made: SK20R11
NGK made: IFR6A11
(b) No large carbon deposit present.
Not wet with gasoline or oil.
(c) Electrode gap: 1.1 mm (0.043 in.)
PREPARATION:
(a) Install the spark plug to the ignition coil, and connect the
ignition coil connector.
(b) Disconnect the injector connector.
(c) Ground the spark plug.
CHECK:
Check if spark occurs while engine is being cranked.
OK:
Spark jumps across electrode gap.
NG Replace or check ignition system (See page
IG-1).
OK
3 Check voltage of ECM terminal for injector of failed cylinder.
PREPARATION:
(a) Remove the glove compartment (See page SF-82).
(b) Turn the ignition switch ON.
CHECK:
Measure the voltage between applicable terminal of the ECM
connector and body ground.
OK:
Voltage: 9 - 14 V

FI6588
FI6538
A00064
10 V
/Division10 V
/Division
GND GND
100 msec./Division (Idling)1 msec./Division (Idling)
Injection duration
(Magnification) Injector Signal Waveform
DI-62
- DIAGNOSTICSENGINE
218 Author
: Date
:
2001 AVALON (RM808U)
Reference: INSPECTION USING OSCILLOSCOPE
With the engine idling, check the waveform between terminals #10 - #60 and E01 of the ECM connector.
HINT:
The correct waveform is as shown.
OK Go to step 5.
NG
4 Check resistance of injector of misfiring cylinder (See page SF-19).
NG Replace injector.
OK
Check for open and short in harness and con-
nector between injector and ECM (See page
IN-30).
5 Check fuel pressure (See page SF-6).
NG Check and repair fuel pump, fuel pipe line and
filter (See page SF-1).

- DIAGNOSTICSENGINE
DI-63
219 Author
: Date
:
2001 AVALON (RM808U)
OK
6 Check injector injection (See page SF-23).
NG Replace injector.
OK
7 Check mass air flow meter (See page SF-31) and engine coolant temperature
sensor (See page SF-73).
NG Repair or replace.
OK
Check compression pressure (See page
EM-3), valve clearance (See page EM-4) and
valve timing (See page EM-21).

A00304
Knock SensorECM
EB1
Male
ConnectorFemale
Connector 1
111
22KNKR
KNKL
EB1
E4
E427
28
FI7050
S06024
S06025
FI6510FI6607A00113
KNK Signal Waveform
0.5 V
/Division
5 msec./Division
100 msec./Division 0V
200 mV
/Division
0V
- DIAGNOSTICSENGINE
DI-65
221 Author
: Date
:
2001 AVALON (RM808U)

Read freeze frame data using TOYOTA hand-held tester or OBD II scan tool. Because freeze frame
records the engine conditions when the 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.
1 Connect OBD II scan tool or TOYOTA hand-held tester, and check knock sensor
circuit.
PREPARATION:
(a) Connect the OBD II scan tool or TOYOTA hand-held tes-
ter to the DLC3.
(b) Disconnect the wire from wire connector EB1.
(c) Connect the terminals of the disconnected EB1 male con-
nector and EB1 female as follows.
Male connector eFemale connector
Terminal 1 e Terminal 2
Terminal 2 e Terminal 1
(d) Turn the ignition switch ON and push the OBD II scan tool
or TOYOTA hand-held tester main switch ON.
(e) After the engine is warmed up, perform quick racing to
4,000 rpm 3 times.
CHECK:
Check the DTC.
RESULT:
Type IDTC same as when vehicle brought in
P0325 " P0325 or P0330 " P0330
Type IIDTC different to when vehicle brought in
P0325 " P0330 or P0330 " P0325
Reference: INSPECTION USING OSCILLOSCOPE

With the engine racing (4,000 rpm), check the waveform
between terminals KNKR, KNKL of the ECM connector
and body ground.
HINT:
The correct waveform is as shown.

Spread the time on the horizontal axis, and confirm that
period of the wave is 141 msec. (Normal mode vibration
frequency of knock sensor: 7.1 kHz)
HINT:
If normal mode vibration frequency is not 7.1 kHz, the sensor
is malfunctioning.
Type II Go to step 3.

DI-66
- DIAGNOSTICSENGINE
222 Author
: Date
:
2001 AVALON (RM808U)
Type I
2 Check for open and short in harness and connector between EB1 connector and
ECM (See page IN-30).
NG Repair or replace harness or connector.
OK
Check and replace ECM (See page IN-30).
3 Check for open and short in harness and connector between EB1 connector and
knock sensor (See page IN-30).
HINT:

If DTC P0325 has changed to P0330, check the knock sensor circuit on the right bank side.

If DTC P0330 has changed to P0325, check the knock sensor circuit on the left bank side.
NG Repair or replace harness or connector.
OK
Replace knock sensor.