2001 TOYOTA AVALON check engine

DI-16
- DIAGNOSTICSENGINE
172 Author
: Date
:
P0440
(DI-74)Evaporative Emission Control
System Malfunction
Hose or tube cracked, holed, damaged or insufficient seal
Fuel tank cap incorrectly installed
Fuel tank cap cracked or damaged
Vacuum hose cracked, holed, blocked, damaged or discon-
nected
Fuel tank cracked, holed or damaged
Charcoal canister cracked, holed or damaged
Open or short in vapor pressure sensor circuit
Vapor pressure sensor
Fuel tank over fill check valve cracked or damaged
ECM

P0441
(DI-80)Evaporative Emission Control
System Incorrect Purge Flow
Vacuum hose cracked, holed blocked, damaged or discon-
nected ((1), (2), (3), (4), (5), (6), (7), (8), (9), (10) and (11) in
Fig. 1)
Fuel tank cap incorrectly installed
Fuel tank cap cracked or damaged
Open or short in vapor pressure sensor circuit
Vapor pressure sensor
Open or short in VSV circuit for EVAP
VSV for EVAP
Open or short in VSV circuit for CCV
VSV for CCV
Open or short in VSV circuit for pressure switching valve
VSV for pressure switching valve
Fuel tank cracked, holed or damaged
Charcoal canister cracked, holed or damaged
Fuel tank over fill check valve cracked or damaged
ECM

P0442
(DI-74)Evaporative Emission Control
System Leak Detected (Small
Leak)
Same as DTC No. P0440
P0446
(DI-80)Evaporative Emission Control
System Vent Control MalfunctionSame as DTC No. P0441
P0450
(DI-97)Evaporative Emission Control
System Pressure Sensor Mal-
function
Open or short in vapor pressure sensor circuit
V
P0451
(DI-97)Evaporative Emission Control
System Pressure Sensor Range/
PerformanceVapor pressure sensor
ECM
P0500
(DI-99)Vehicle Speed Sensor Malfunc-
tionCombination meter
Open or short in speed sensor circuit
ECM

P0505
(DI-102)Idle Control System Malfunction
Open or short in IAC valve circuit
IAC valve is stuck or closed
Open or short in A/C signal circuit
Air induction system
ECM

*1: MIL lights up
*2: MIL light up or blinking

DI078-07
Vehicle Brought to Workshop
Customer Problem Analysis P. DI-2
Problem Symptom Confirmation
If the engine does not start, perform steps 10 and 12 firstConnect the OBD II scan tool or TOYOTA hand-held tester to DLC3 P. DI-3
If the display indicates a communication fault in the tool, inspect DLC3 P. DI-3

Check DTC and Freezed Frame Data (Precheck)
Record or Print DTC and Freezed Frame Data P. DI-3
Clear DTC and Freezed Frame Data P. DI-3
Visual Inspection
Setting the Check Mode Diagnosis P. DI-3
Symptom Simulation P. IN-20
DTC Chart P. DI-14
Problem Symptoms Table P. DI-22
Circuit Inspection P. DI-23
Adjustment, Repair
DTC Check P. DI-3
Titles insideare titles of pages in
in the bottom portion. See the indicated
pages for detailed explanations.this manual with the page number indicated
Malfunction
occurs.Malfunction does not occur.
Parts Inspection
Check for Intermittent Problems P. DI-3
Identification of Problem
Confirmation Test
End 1
2
3
4
5
6
7
108
9
11
12
13
15 14
16
Normal Malfunction code.
17Basic Inspection P. DI-3
- DIAGNOSTICSENGINE
DI-1
157 Author
: Date
:
2001 AVALON (RM808U)
ENGINE
HOW TO PROCEED WITH TROUBLESHOOTING
Troubleshoot in accordance with the procedure on the following page.

DI07A-09
S05349
A10838
TOYOTA Hand-Held tester
- DIAGNOSTICSENGINE
DI-3
159 Author
: Date
:
2001 AVALON (RM808U)
PRE-CHECK
1. DIAGNOSIS SYSTEM
(a) Description

When troubleshooting OBD II vehicles, the only dif-
ference from the usual troubleshooting procedure
is that you connect the vehicle to the OBD II scan
tool complying with SAE J1978 or TOYOTA hand-
held tester, and read off various data output from
the vehicle's ECM.

OBD II regulations require that the vehicle's on-
board computer lights up the Malfunction Indicator
Lamp (MIL) on the instrument panel when the com-
puter detects a malfunction in the emission control
system/components or in the powertrain control
components which affect vehicle emissions, or a
malfunction in the computer. In addition to the MIL
lighting up when a malfunction is detected, the ap-
plicable Diagnostic Trouble Codes (DTCs) pre-
scribed by SAE J2012 are recorded in the ECM
memory (See page DI-14).
If the malfunction does not reoccur in 3 consecutive trips, the
MIL goes off automatize but the DTC remain recorded in the
ECM memory.

To check the DTC, connect the OBD II scan tool or
TOYOTA hand-held tester to the Data Link Con-
nector 3 (DLC3) on the vehicle. The OBD II scan
tool or TOYOTA hand-held tester also enables you
to erase the DTC and check freezed frame data and
various forms of engine data (For operating instruc-
tions, see the OBD II scan tool's instruction book.).
DTC include SAE controlled codes and manufac-
turer controlled codes. SAE controlled codes must
be set as prescribed by the SAE, while manufactur-
er controlled codes can be set freely by the
manufacturer within the prescribed limits (See DTC
chart on page DI-14).

DI-4
- DIAGNOSTICSENGINE
160 Author
: Date
:
2001 AVALON (RM808U)

The diagnosis system operates in normal mode
during normal vehicle use. It also has a check mode
for technicians to simulate malfunction symptoms
and troubleshoot. Most DTC use 2 trip detection
logic* to prevent erroneous detection, and ensure
thorough malfunction detection. By switching the
ECM to check mode when troubleshooting, the
technician can cause the MIL to light up for a mal-
function that is only detected once or momentarily
(TOYOTA hand-held tester only). (See step 2)

*2 trip detection logic:
When a malfunction is first detected, the malfunc-
tion is temporarily stored in the ECM memory. (1st
trip)
If the same malfunction is detected again during the second
drive test, this second detection causes the MIL to light up. (2nd
trip) the 2 trip repeats the same mode a 2nd time (However, the
ignition switch must be turned OFF between the 1st trip and 2nd
trip.).

Freeze frame data:
Freeze frame data records the engine condition
when a misfire (DTCs P0300 - P0306) or fuel trim
malfunction (DTCs P0171 and P0172) or other mal-
function (first malfunction only), is detected. Be-
cause freeze frame data records the engine condi-
tions (fuel system, calculated load, engine coolant
temperature, fuel trim, engine speed, vehicle
speed, etc.) when the malfunction is detected.
When troubleshooting, it is useful for determining
whether the vehicle was running or stopped, the en-
gine was warmed up or not, the air-fuel ratio was
lean or rich, etc. at the time of the malfunction.
Priorities for troubleshooting:
If troubleshooting priorities for multiple DTCs are given in the
applicable DTC chart, these should be followed.
If no instructions are given, troubleshoot DTCs according to the
following priorities.
(1) DTC other than fuel trim malfunction (DTCs P0171
and P0172), and misfire (DTCs P0300 - P0306).
(2) Fuel trim malfunction (DTCs P0171 and P0172).
(3) Misfire (DTCs P0300 - P0306).

A04550
DLC3
1
234
56
7
8
9
10 11 12 13 1415
16
S05349
- DIAGNOSTICSENGINE
DI-5
161 Author
: Date
:
2001 AVALON (RM808U)
(b) Check the DLC3.
The vehicle's ECM uses ISO 9141-2 for communication.
The terminal arrangement of DLC3 complies with SAE
J1962 and matches the ISO 9141-2 format.
Terminal No.Connection/Voltage or ResistanceCondition
7Bus  Line/Pulse generationDuring transmission
4Chassis Ground e Body Ground/1 W or lessAlways
5Signal Ground e Body Ground/1 W or lessAlways
16Battery Positive e Body Ground/9 - 14 VAlways
HINT:
If your display shows UNABLE TO CONNECT TO VEHICLE
when you have connected the cable of the OBD II scan tool or
TOYOTA hand-held tester to the DLC3, turned the ignition
switch ON and operated the scan tool, there is a problem on the
vehicle side or tool side.

If communication is normal when the tool is connected to
another vehicle, inspect the DLC3 on the original vehicle.

If communication is still not possible when the tool is con-
nected to another vehicle, the problem is probably in the
tool itself, so consult the Service Department listed in the
tool's instruction manual.
2. INSPECT DIAGNOSIS (Normal Mode)
(a) Check the MIL.
(1) The MIL comes on when the ignition switch is turned
ON and the engine is not running.
HINT:
If the MIL does not light up, troubleshoot the combination meter
(See page BE-53).
(2) When the engine started, the MIL should go off. If
the lamp remains on, the diagnosis system has de-
tected a malfunction or abnormality in the system.
(b) Check the DTC.
NOTICE:

If there is no DTC in the normal mode, check the 1st
trip DTC using Continuous Test Results function
(Mode 7 for SAE J1979) or the OBD II scan tool or TOY-
OTA hand-held tester.

DI-6
- DIAGNOSTICSENGINE
162 Author
: Date
:
2001 AVALON (RM808U)

TOYOTA hand-held tester only:
When the diagnosis system is switched from the nor-
mal mode to the check mode, it erases all DTC and
freezed frame data recorded in the normal mode. So
before switching modes, always check the DTC and
freezed frame data, and note them down.
(1) Prepare the OBD II scan tool (complying with SAE
J 1978) or TOYOTA hand-held tester.
(2) Connect the OBD II scan tool or TOYOTA hand-
held tester to the DLC3 at the lower center of the
instrument panel.
(3) Turn the ignition switch ON and push the OBD II
scan tool or TOYOTA hand-held tester switch ON.
(4) Use the OBD II scan tool or TOYOTA hand-held
tester to check the DTC and freezed frame data and
note them down (For operating instructions, see the
OBD II scan tool's instruction book.).
If there is no DTC in the normal mode, check the 1st
trip DTC using Continuous Test Results function
(Mode 7 for SAE J1979) on the OBD II scan tool or
TOYOTA hand-held tester.
(5) See page DI-14 to confirm the details of the DTC.
NOTICE:

When simulating symptoms with an OBD II scan tool
(excluding TOYOTA hand-held tester) to check the
DTC, use the normal mode. For code on the DTC chart
subject to º2 trip detection logicº, perform the follow-
ing either action.

Turn the ignition switch OFF after the symptom is
simulated the 1st time. Then repeat the simulation
process again. When the problem has been simulated
twice, the MIL lights up and the DTCs are recorded in
the ECM.

Check the 1st trip DTC using Mode 7 (Continuous Test
Results) for SAE J1979.
(c) Clear the DTC.
The DTCs and freezed frame data will be erased by either
action.

Operating the OBD II scan tool (complying
with SAE J1978) or TOYOTA hand-held tes-
ter to erase the codes. (See the OBD II scan
tool's instruction book for operating instruc-
tions.)

Disconnecting the battery terminals or EFI
fuse.

FI3605
Flashing
ON
OFF
0.13 Seconds
- DIAGNOSTICSENGINE
DI-7
163 Author
: Date
:
2001 AVALON (RM808U)
NOTICE:
If the TOYOTA hand-held tester switches the ECM from the
normal mode to the check mode or vice-versa, or if the
ignition switch is turned from ON to ACC or OFF during the
check mode, the DTCs and freezed frame data will be
erased.
3. INSPECT DIAGNOSIS (Check Mode)
HINT:
TOYOTA hand-held tester only:
Compared to the normal mode, the check mode has an in-
creased sensitivity to detect malfunctions.
Furthermore, the same diagnostic items which are detected in
the normal mode can also be detected in the check mode.
Check the DTC.
(1) Initial conditions.

Battery positive voltage 11 V or more

Throttle valve fully closed

Transmission in P or N position

A/C switched OFF
(2) Turn the ignition switch OFF.
(3) Prepare the TOYOTA hand-held tester.
(4) Connect the TOYOTA hand- held tester to the
DLC3 at the lower center of the instrument panel.
(5) Turn the ignition switch ON and push the TOYOTA
hand-held tester switch ON.
(6) Switch the TOYOTA hand-held tester from the nor-
mal mode to the check mode (Check that the MIL
flashes.).
NOTICE:
If the TOYOTA hand-held tester switches the ECM from the
normal mode to the check mode or vice-versa, or if the
ignition switch is turned from ON to ACC or OFF during the
check mode, the DTC and freezed frame data will be
erased.
(7) Start the engine (The MIL goes out after the engine
start.).
(8) Simulate the conditions of the malfunction de-
scribed by the customer.
NOTICE:
Leave the ignition switch ON until you have checked the
DTC, etc.
(9) After simulating the malfunction conditions, use the
TOYOTA hand-held tester diagnosis selector to
check the DTC and freezed frame data, etc.

DI-8
- DIAGNOSTICSENGINE
164 Author
: Date
:
2001 AVALON (RM808U)
HINT:
Take care not to turn the ignition switch OFF. Turning the ignition
switch OFF switches the diagnosis system from the check
mode to the normal mode, so all DTC, etc. are erased.
(10) After checking the DTC, inspect the applicable cir-
cuit.
4. FAIL-SAFE CHART
If any of the following codes is recorded, the ECM enters fail-safe mode.
DTC No.Fail-Safe OperationFail-Safe Deactivation Conditions
P0100Ignition timing fixed at 10° BTDCReturned to normal condition
P0110Intake air temp. is fixed at 20°C (68°F)Returned to normal condition
P0115Engine coolant temp. is fixed at 80°C (176°F)Returned to normal condition
P0120VTA is fixed at 0°The following condition must be repeated at least 2 times con-
secutively 0.1 V
VTA
0.95 V, SPD = 0 km/h
P0135
P0141
P0155
P1135
P1155
The heater circuit in witch an abnormality is detected is
turned offIgnition switch OFF
P0325
P0330Max. timing retardationIgnition switch OFF
P1300Fuel cutReturned to normal condition
5. CHECK FOR INTERMITTENT PROBLEMS
TOYOTA hand-held tester only:
By putting the vehicle's ECM in the check mode, 1 trip detection logic is possible instead of 2 trip detection
logic and sensitivity to detect open circuits is increased. This makes it easier to detect intermittent problems.
(1) Clear the DTC (See step 2).
(2) Set the check mode (See step 3).
(3) Perform a simulation test (See page IN-20).
(4) Check the connector and terminal (See page IN-30).
(5) Handle the connector (See page IN-30).
6. BASIC INSPECTION
When the malfunction code is not confirmed in the DTC check, troubleshooting should be performed in order
for all possible circuits to be considered as the cause of the problems. In many cases, by carrying out the
basic engine check shown in the following flow chart, the location causing the problem can be found quickly
and efficiently. Therefore, use of this check is essential in engine troubleshooting.
1 Is battery positive voltage 11 V or more when engine is stopped?
NO Charge or replace battery.
YES
2 Is engine cranked?