2001 TOYOTA AVALON coolant
[x] Cancel search: coolantPage 932 of 1897
DI-48
- DIAGNOSTICSENGINE
204 Author: Date:
2001 AVALON (RM808U)
DTC P0128 Thermostat Malfunction
CIRCUIT DESCRIPTION
If the water temperature becomes 75°C (167°F) or more, it is abnormal.
If not due to the thermostat malfunction, it is abnormal.
DTC No.DTC Detecting ConditionTrouble Area
P0128
Condition (a), (b) or (c):
(a) After starting engine at 20°C (68°F)
(b) After engine is warmed up
(c) THW < 75°C (167°F)Thermostat
Cooling system
Engine coolant temp. sensor
ECM
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 thermostat (See page CO-1 1).
NG Replace thermostat.
YES
2 Are there any other codes (besides DTC P0128) being output?
YES Go to relevant DTC chart (See page DI-14).
NG
Check and replace ECM (See page IN-30).
DI6T2-01
Page 937 of 1897
DI-58
- DIAGNOSTICSENGINE
214 Author: Date:
2001 AVALON (RM808U)
DTC P0300 Random/Multiple Cylinder Misfire Detected
DTC P0301 Cylinder 1 Misfire Detected
DTC P0302 Cylinder 2 Misfire Detected
DTC P0303 Cylinder 3 Misfire Detected
DTC P0304 Cylinder 4 Misfire Detected
DTC P0305 Cylinder 5 Misfire Detected
DTC P0306 Cylinder 6 Misfire Detected
CIRCUIT DESCRIPTION
Misfire: The ECM uses the crankshaft position sensor and camshaft position sensor to monitor changes in
the crankshaft rotation for each cylinder.
The ECM counts the number of times the engine speed change rate indicates that misfire has occurred.
When the misfire rate equals or exceeds the count indicating that the engine condition has deteriorated, the
MIL lights up.
If the misfire rate is high enough and the driving conditions will cause catalyst overheating, the MIL blinks
when misfiring occurs.
DTC No.DTC Detecting ConditionTrouble Area
P0300Misfiring of random cylinders is detected during any particular
200 or 1,000 revolutionsOpen or short in engine wire
Connector connection
Vacuum hose connection
P0301
P0302
P0303For any particular 200 revolutions for engine, misfiring is de-
tected which can cause catalyst overheating (This causes MIL
to blink)
Ignition system
Injector
Fuel pressure
Mass air flow meter
Engine coolant tempsensorP0303
P0304
P0305
P0306For any particular 1,000 revolutions of engine, misfiring is de-
tected which causes a deterioration in emission (2 trip detec-
tion logic)
Engine coolant temp. sensor
Compression pressure
Valve clearance
Valve timing
ECM
DI07S-10
Page 939 of 1897
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
Page 942 of 1897
- 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).
Page 1021 of 1897
- DIAGNOSTICSENGINE
DI-53
209 Author: Date:
DTC P0171 System too Lean (Fuel Trim)
DTC P0172 System too Rich (Fuel Trim)
DTC P0174 System too Lean (A/F Lean Malfunction,
Bank2)
DTC P0175 System too Rich (Bank2)
CIRCUIT DESCRIPTION
Fuel trim refers to the feedback compensation value compared to the basic injection time. Fuel trim includes
short-term fuel trim and long-term fuel trim.
Short-term fuel trim is the short-term fuel compensation used to maintain the air-fuel ratio at its ideal
theoretical value.
The signal from the A/F sensor is approximately proportional to the existing air-fuel ratio, and ECM compar-
ing it with the ideal theoretical value, the ECM reduces fuel volume immediately if the air-fuel ratio is rich
and increases fuel volume if it is lean.
Long-term fuel trim compensates the deviation from the central value of the short-term fuel trim stored up
by each engine tolerance, and the deviation from the central value due to the passage of time and changes
of using environment.
If both the short-term fuel trim and long-term fuel trim exceed a certain value, it is detected as a malfunction
and the MIL lights up.
DTC No.DTC Detecting ConditionTrouble Area
P0171
P0174When air-fuel ratio feedback is stable after engine warming up,
fuel trim is considerably in error on rich side (2 trip detection
logic)
Air induction system
Injector blockage
Mass air flow meter
Engine coolant temp. sensor
Fuel pressure
Gas leakage on exhaust system
Open or short in A/F sensor (bank 1, 2 sensor 1) circuit
A/F sensor (bank 1, 2 sensor 1)
ECM
P0172
P0175When air-fuel ratio feedback is stable after engine warming up,
fuel trim is considerably in error on lean side (2 trip detection
logic)
Injector leak, blockage
Mass air flow meter
Engine coolant temp. sensor
Ignition system
Fuel pressure
Gas leakage on exhaust system
Open or short in A/F sensor (bank 1, 2 sensor 1) circuit
A/F sensor (bank 1, 2 sensor 1)
ECM
DI6T4-03
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 1030 of 1897
DI07B-20
DI-14
- DIAGNOSTICSENGINE
170 Author: Date:
DIAGNOSTIC TROUBLE CODE CHART
HINT:
Parameters listed in the chart may not be exactly the same as your reading due to the type of instrument
or other factors.
If a malfunction code is displayed during the DTC check in check mode, check the circuit for the codes listed
in the table below. For details of each code, turn to the page referred to under the ''See page '' for the respec-
tive ''DTC No.'' in the DTC chart.
SAE CONTROLLED
DTC No.
(See page)Detection ItemTrouble AreaMIL*1Memory
P0100
(DI-23)Mass Air Flow Circuit Malfunc-
tionOpen or short in mass air flow meter circuit
Mass air flow meter
ECM
P0101
(DI-27)Mass Air Flow Circuit Range/
Performance ProblemMass air flow meter
P0110
(DI-28)Intake Air Temp. Circuit Malfunc-
tionOpen or short in intake air temp. sensor circuit
Intake air temp. sensor (built into mass air flow meter)
ECM
P0115
(DI-32)Engine Coolant Temp. Circuit
MalfunctionOpen or short in engine coolant temp. sensor circuit
Engine coolant temp. sensor
ECM
P0116
(DI-36)Engine Coolant Temp. Circuit
Range/Performance ProblemCooling system
Engine coolant temp. sensor
P0120
(DI-38)Throttle/Pedal Position Sensor/
Switch ºAº Circuit MalfunctionOpen or short in throttle position sensor circuit
Throttle position sensor
ECM
P0121
(DI-42)Throttle/Pedal Position Sensor/
Switch ºAº Circuit Range/Perfor-
mance Problem
Throttle position sensor
P0125
(DI-43)Insufficient Coolant Temp. for
Closed Loop Fuel Control
Open or short in A/F sensor (bank 1, 2 sensor 1) circuit
A/F sensor (bank 1, 2 sensor 1)
Air induction system
Fuel pressure
Injector
Gas leakage on exhaust system
ECM
P0128
(DI-48)Thermostat Malfunction
Thermostat
Cooling system
Engine coolant temp. sensor
ECM
P0136
(DI-49)Oxygen Sensor Circuit Malfunc-
tion (Bank 1 Sensor 2)Open or short in heated oxygen sensor circuit
Heated oxygen sensor
P0141
(DI-51)Oxygen Sensor Heater Circuit
Malfunction (Bank 1 Sensor 2)Open or short in heater circuit of heated oxygen sensor
Heated oxygen sensor heater
ECM
Page 1031 of 1897
- DIAGNOSTICSENGINE
DI-15
171 Author: Date:
P0171
(DI-53)System too Lean (Fuel Trim)
Air induction system
Injector blockage
Mass air flow meter
Engine coolant temp. sensor
Fuel pressure
Gas leakage on exhaust system
Open or short in A/F sensor (bank 1, 2 sensor 1) circuit
A/F sensor (bank 1, 2 sensor 1)
ECM
P0172
(DI-53)System too Rich (Fuel Trim)
Injector leak, blockage
Mass air flow meter
Engine coolant temp. sensor
Ignition system
Fuel pressure
Gas leakage on exhaust system
Open or short in A/F sensor (bank 1, 2 sensor 1) circuit
A/F sensor (bank 1, 2 sensor 1)
ECM
P0174
(DI-53)System too Lean
(A/F Lean Malfunction)Same as DTC P0171
P0175
(DI-53)System too Rich
(A/F Rich Malfunction)Same as DTC P0172
P0300
(DI-58)Random/Multiple Cylinder Misfire
Detected
P0301
(DI-58)Cylinder 1 Misfire DetectedOpen or short in engine wire
Connector connection
Vh tiP0302
(DI-58)Cylinder 2 Misfire Detected
Vacuum hose connection
Ignition system
Injector
P0303
(DI-58)Cylinder 3 Misfire Detected
Injector
Fuel pressure
Mass air flow meter
*2
P0304
(DI-58)Cylinder 4 Misfire Detected
Mass air flow meter
Engine coolant temp. sensor
Compression pressure
Vl lP0305
(DI-58)Cylinder 5 Misfire Detected
Valve clearance
Valve timing
ECM
P0306
(DI-58)Cylinder 6 Misfire Detected
ECM
P0325
(DI-64)Knock Sensor 1 Circuit Malfunc-
tion (Bank 1)Open or short in knock sensor 1 circuit
Knock sensor 1 (looseness)
ECM
P0330
(DI-64)Knock Sensor 2 Circuit Malfunc-
tion (Bank 2)Open or short in knock sensor 2 circuit
Knock sensor 2 (looseness)
ECM
P0335
(DI-67)Crankshaft Position Sensor ºAº
Circuit Malfunction
Open or short in crankshaft position sensor circuit
Crankshaft position sensor
Crankshaft timing pulley
ECM
P0340
(DI-69)Camshaft Position Sensor Circuit
Malfunction
Open or short in camshaft position sensor circuit
Camshaft position sensor
Camshaft timing gear
ECM
P0420
(DI-71)Catalyst System Efficiency Be-
low Threshold (Bank 1)
Gas leakage on exhaust system
A/F sensor (bank 1, 2 sensor 1)
Heated oxygen sensor (bank 1 sensor 2)
Three-way catalytic converter