check engine TOYOTA AVALON 2001 Service Repair Manual
[x] Cancel search | Manufacturer: TOYOTA, Model Year: 2001, Model line: AVALON, Model: TOYOTA AVALON 2001Pages: 1897, PDF Size: 26.61 MB
Page 1013 of 1897
A11416
Fusible
Link
Block
FL
Main
BatteryStop Light
Switch
ALT
B
F10
F6STOP
R
211D 1B
1E
45
Light
Failure
Sensor 7
2
To Stop LightE8 15ECM
STP
E1 Driver Side J/B
3 11
W
1 1
16
4C 3C
3164F3F 3
5IK1 1D 1
1GG-W
G-WDriver Side J/B
J/B No.3
J/B No.4
G-W
G-W G-W G-W
DI-134
- DIAGNOSTICSENGINE
290 Author: Date:
2001 AVALON (RM808U)
DTC P1520 Stop Light Switch Signal Malfunction
CIRCUIT DESCRIPTION
This signal is used to detect when the brakes have been applied. The STP signal voltage is the same as
the voltage supplied to the stop lights.
The STP signal is used mainly to control the fuel cut-off engine speed (The fuel cut-off engine speed is re-
duced slightly when the vehicle is braking.).
DTC No.DTC Detecting ConditionTrouble Area
P1520
Stop light switch does not turn off when repeating driving at 30
km or more 10 time or more after depressing brake (2 trip
detection logic)Short in stop light switch signal circuit
Stop light switch
ECM
WIRING DIAGRAM
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 operation of stop light.
CHECK:
Check if the stop lights go on and off normally when the brake pedal is operated and released.
NG Check and repair stop light circuit.
DI088-09
Page 1014 of 1897
A02037
ON
ON
STP
Brake Pedal
DepressedBrake Pedal
Released
(+)
(-)
- DIAGNOSTICSENGINE
DI-135
291 Author: Date:
2001 AVALON (RM808U)
OK
2 Check STP signal.
When using TOYOTA hand-held tester:
PREPARATION:
(a) Connect the TOYOTA hand-held tester to the DLC3.
(b) Turn the ignition switch ON and push the TOYOTA hand-
held tester main switch ON.
CHECK:
Read the STP signal on the TOYOTA hand-held tester.
OK:
Brake PedalSTP Signal
DepressedON
ReleasedOFF
When not using TOYOTA hand-held tester:
PREPARATION:
Turn the ignition switch ON.
CHECK:
Check the voltage between terminal STP of the ECM connector
and body ground.
OK:
Brake PedalVoltage
Depressed7.5 - 14 V
ReleasedBelow 1.5 V
OK Check for intermittent problems
(See page DI-3).
NG
3 Check harness and connector between ECM and stop light switch
(See page IN-30).
NG Repair or replace harness or connector.
OK
Check and replace ECM (See page IN-30).
Page 1016 of 1897
A02038
LOCK
BATT
(+)
(-)
A11423
Engine Room J/B
EFI No.1
Fuse
- DIAGNOSTICSENGINE
DI-137
293 Author: Date:
2001 AVALON (RM808U)
1 Check voltage between terminal BATT of ECM connector and body ground.
PREPARATION:
Remove the glove compartment (See page SF-82).
CHECK:
Measure the voltage between terminal BATT 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 EFI No.1 fuse.
PREPARATION:
Remove the EFI No.1 fuse from the engine room J/B.
CHECK:
Check the continuity of the EFI No.1 fuse.
OK:
Continuity
NG Check for short in all harness and components
connected to EFI No.1 fuse.
OK
Check and repair harness or connector be-
tween battery and EFI No.1 fuse, and EFI No.1
fuse and ECM.
Page 1017 of 1897
DI-138
- DIAGNOSTICSENGINE
294 Author: Date:
2001 AVALON (RM808U)
DTC P1656 OCV Circuit Malfunction (bank 1)
DTC P1663 OCV Circuit Malfunction (bank 2)
CIRCUIT DESCRIPTION
Refer to DTC P1349, P1354 on page DI-127.
DTC No.DTC Detecting ConditionTrouble Area
P1656
P1663Open or short in oil control valve circuit
Open or short in OCV circuit
OCV
ECM
WIRING DIAGRAM
Refer to DTC P1349, P1354 on page DI-127.
INSPECTION PROCEDURE
HINT:
If DTC P1656 dysplayed, check left bank OCV circuit.
If DTC P1663 dysplayed, check right bank OCV circuit.
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.
TOYOTA hand-held tester:
1 Check OCV circuit.
PREPARATION:
(a) Start the engine and warmed it up.
(b) Connect the TOYOTA hand-held tester and select the VVT from the ACTIVE TEST menu.
CHECK:
Check the engine speed when operate the OCV by the TOYOTA hand-held tester.
OK:
VVT system is OFF (OCV is OFF): Normal engine speed
VVT system is ON (OCV is ON): Rough idle or engine stalled
OK Check for intermittent problems
(See page DI-3).
NG
DI6TC-01
Page 1018 of 1897
A06076A11891
- DIAGNOSTICSENGINE
DI-139
295 Author: Date:
2001 AVALON (RM808U)
2 Check operation of OCV.
PREPARATION:
(a) Start the engine and warmed it up.
(b) Disconnect the OCV connector.
(c) Apply battery positive voltage between terminals of the
OCV.
CHECK:
Check the engine speed.
OK:
Rough idle or engine stalled.
NG Replace OCV.
OK
3 Check voltage between terminals OCV+ and OCV- of ECM connector (See page
DI-127, step 3).
NG Check and replace ECM (See page IN-30).
OK
4 Check for open and short in harness and connector between OCV and ECM (See
page IN-30).
NG Repair or replace.
OK
Check for intermittent problems (See page
DI-3).
Page 1019 of 1897
A06076A11891
DI-140
- DIAGNOSTICSENGINE
296 Author: Date:
2001 AVALON (RM808U)
OBD II scan tool (excluding TOYOTA hand-held tester):
1 Check operation of OCV.
PREPARATION:
(a) Start the engine and warmed it up.
(b) Disconnect the OCV connector.
(c) Apply battery positive voltage between terminals of the
OCV.
CHECK:
Check the engine speed.
OK:
Rough idle or engine stalled
NG Replace OCV.
OK
2 Check voltage between terminals OCV+ and OCV- of ECM connector (See page
DI-127, step 3).
NG Check and replace ECM (See page IN-30).
OK
3 Check for open and short in harness and connector between OCV and ECM (See
page IN-30).
NG Repair or replace.
OK
Check for intermittent problems (See page
DI-3).
Page 1022 of 1897
DI-54
- DIAGNOSTICSENGINE
210 Author: Date:
HINT:
When the DTC P0171 or P0174 is recorded, the actual air-fuel ratio is on the lean side. When DTC
P0172 or P0175 is recorded, the actual air-fuel ratio is on the rich side.
If the vehicle runs out of fuel, the air-fuel ratio is lean and DTC P0171 or P0174 is recorded. The MIL
then comes on.
If the total of the short-term fuel trim value and the long-term fuel trim value is within + 35 % (80°C
(176°F) or more), the system is functioning normally.
The A/F sensors (bank 1, 2 sensor 1) output voltage and the short-term fuel trim value can be read
using the OBD II scan tool or hand-held tester.
The ECM controls the voltage of AFR+, AFL+, AFR- and AFL- terminals of ECM to the fixed voltage.
Therefore, it is impossible to confirm the A/F sensor output voltage without OBD II scan tool or hand-
held tester.
OBD II scan tool (excluding hand-held tester) displays the one fifth of the A/F sensors (bank 1, 2 sen-
sor 1) output voltage which is displayed on the hand-held tester.
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 air induction system (See page SF-1).
NG Repair or replace.
OK
2 Check injector injection (See page SF-23).
NG Replace injector.
OK
Page 1023 of 1897
- DIAGNOSTICSENGINE
DI-55
211 Author: Date:
3 Check mass air flow meter (See page SF-31) and engine coolant temperature
sensor (See page SF-73).
NG Repair or replace.
OK
4 Check for spark and ignition (See page IG-1).
NG Repair or replace.
OK
5 Check fuel pressure (See page SF-6).
NG Check and repair fuel pump, pressure regulator,
fuel pipe line and filter.
OK
6 Check gas leakage on exhaust system.
NG Repair or replace.
OK
Page 1024 of 1897
DI-56
- DIAGNOSTICSENGINE
212 Author: Date:
7 Check output voltage A/F sensor (bank 1, 2 sensor 1).
PREPARATION:
(a) Connect the OBDII scan tool or TOYOTA hand-held tester to the DLC3.
(b) Warm up the A/F sensor with the engine speed at 2,500 rpm for approx. 90 sec.
CHECK:
Read the voltage value of the A/F sensor on the screen of OBDII scan tool or TOYOTA hand-held tester
when you perform all the following conditions.
HINT:
The voltage of the AFR+ or AFL+ terminal of the ECM is 3.3 fixed the AFR- or AFL- terminal is 3.0 V fixed.
Therefore, it is impossible to check the A/F sensor output voltage at the terminals (AFR+, AFL+/AFR-, AFL-)
of the ECM.
OK:
ConditionA/F Sensor Voltage value
Engine idling
Engine racingNot remains at 3.30 V (0.660 V*)
Not remains at38V(076V*) or moreDriving at engine speed 1,500 rpm or more and vehicle
speed 40 km/h (25mph) or more, and operate throttle valve
open and closeNot remains at 3.8 V (0.76 V*) or more
Not remains at 2.8 V (0.56 V*) or less
*: When you use OBDII scan tool (excluding TOYOTA hand-held tester)
HINT:
During fuel enrichment, there is a case that the output voltage of the A/F sensor is below 2.8 V (0.56
V*), it is normal.
During fuel cut, there is a case that the output voltage of the A/F sensor is above 3.8 V (0.76 V*), it
is normal.
If the output voltage of the A/F sensor remains at 3.30 V (0.660 V*) even after performing all the above
conditions, the A/F sensor circuit may be open.
If the output voltage of the A/F sensor remains at 3.8 V (0.76 V*) or more, or 2.8 V (0.56 V*) or less
even after performing all the above conditions, the A/F sensor circuit may be short.
*: When you use the OBDII scan tool (excluding TOYOTA hand-held tester).
OK Go to step 9.
NG
Page 1025 of 1897
- DIAGNOSTICSENGINE
DI-57
213 Author: Date:
8 Check for open and short in harness and connector between ECM and A/F sen-
sors (bank 1, 2 sensor 1) (See page IN-30).
NG Repair or replace harness or connector.
OK
Replace A/F sensor.
9 Perform confirmation driving pattern (See page DI-106).
Go
10 Is there DTC P0171, P0172, P0174 or P0175 being output again?
YES Check and replace ECM (See page IN-30).
NO
11 Did vehicle runs out of fuel in past?
NO Check for intermittent problems
(See page DI-3).
YES
DTC P0171, P0172, P0174 or P0175 is caused
by running out of fuel.