± DIAGNOSTICSENGINE (1MZ±FE)
DI±215
450 Author: Date:
2. MANUFACTURER CONTROLLED
DTC No.
(See Page)Detection ItemTrouble AreaMIL*1Memory
*2
P1130
(DI±340)A/F Sensor Circuit
Range/Performance Malfunction
(Bank 1 Sensor 1)Open or short in A/F sensor circuit
A/F sensor (bank 1 sensor 2)
ECM
*2
P1133
(DI±345)A/F Sensor Circuit Response
Malfunction
(Bank 1 Sensor 1)
A/F sensor (bank 1 sensor 2)
*2
P1135
(DI±349)A/F Sensor Heater Circuit
Malfunction
(Bank1 Sensor 1)Open or short in A/F sensor (bank 1 sensor 2)
A/F sensor (bank 1 sensor 2) heater
ECM
*2
P1150
(DI±340)A/F Sensor Circuit
Range/Performance Malfunction
(Bank2 Sensor 1)
Same as DTC No. P1130
*2
P1153
(DI±345)A/F Sensor Circuit Response
Malfunction
(Bank 2 Sensor 1)
Same as DTC No. P1133
*2
P1155
(DI±349)A/F Sensor Heater Circuit
Malfunction
(Bank 2 Sensor 1)
Same as DTC No. P1135
P1300
(DI±351)Igniter Circuit Malfunction
Open or short in IGF or IGT circuit from igniter to ECM
Igniter
ECM
P1335
(DI±357)Crankshaft Position Sensor
Circuit Malfunction
(during engine running)Open or short in crankshaft position sensor circuit
Crankshaft position sensor
Starter
ECM
±
P1410
(DI±358)EGR Valve Position Sensor
Circuit MalfunctionOpen or short in EGR valve position sensor circuit
EGR valve position sensor
ECM
P1411
(DI±362)EGR Valve Position Sensor
Circuit Range/Performance
Problem
EGR valve position sensor
P1520
(DI±363)Stop Light Switch Signal
MalfunctionShort in stop light switch signal circuit
Stop light switch
ECM
P1600
(DI±366)ECM BATT MalfunctionOpen in back up power source circuit
ECM
P1780
(DI±368)Park/Neutral Position Switch
MalfunctionShort in park/neutral position switch circuit
Park/neutral position switch
ECM
*1: MIL lights up, ± MIL does not light up
*2: Only for California specification vehicles
± DIAGNOSTICSENGINE (1MZ±FE)
DI±267
502 Author: Date:
DTC P0171 System too Lean (Fuel Trim)
(Only for California Spec.)
DTC P0172 System too Rich (Fuel Trim)
(Only for California Spec.)
CIRCUIT DESCRIPTION
Fuel trim refers to the feedback compensation value compared against 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
When air fuel ratio feedback is stable after engine warming up,
fuel trim is considerably in error on RICH side
(2 trip detection logic)
Gas leakage on exhaust system
Air intake (hose loose)
Fuel line pressure
Injector blockage
Mass air flow meter
Engine coolant temp. sensor
A/F sensors (bank 1, 2 sensor 1)
P0172
When air fuel ratio feedback is stable after engine warming up,
fuel trim is considerably in error on LEAN side
(2 trip detection logic)
Gas leakage on exhaust system
Fuel line pressure
Injector leak, blockage
Mass air flow meter
Engine coolant temp. sensor
A/F sensors (bank 1, 2 sensor 1)
DI07R±05
DI±272
± DIAGNOSTICSENGINE (1MZ±FE)
507 Author: Date:
DTC P0171 System too Lean (Fuel Trim)
(Except California Spec.)
DTC P0172 System too Rich (Fuel Trim)
(Except California Spec.)
CIRCUIT DESCRIPTION
Fuel trim refers to the feedback compensation value compared against 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 heated oxygen sensor indicates whether the air±fuel ratio is RICH or
LEAN compared to the ideal theoretical value, triggering a reduction in fuel volume if the air±fuel ratio is rich,
and an increase in fuel volume if it is lean.
Long±term fuel trim is overall fuel compensation carried out long±term to compensate for continual deviation
of the short±term fuel trim from the central value due to individual engine differences, wear over time and
changes in the usage environment.
If both the short±term fuel trim and long±term fuel trim are LEAN or RICH beyond a certain value, it is
detected as a malfunction and the MIL lights up.
DTC No.DTC Detecting ConditionTrouble Area
P0171
When air fuel ratio feedback is stable after engine warming up,
fuel trim is considerably in error on RICH side
(2 trip detection logic)
Air intake (hose loose)
Fuel line pressure
Injector blockage
Heated oxygen sensors (bank 1, 2 sensor 1) malfunction
Mass air flow meter
Engine coolant temp. sensor
Gas leakage on exhaust system
P0172
When air fuel ratio feedback is stable after engine warming up,
fuel trim is considerably in error on LEAN side
(2 trip detection logic)
Fuel line pressure
Injector leak, blockage
Heated oxygen sensors (bank 1, 2 sensor 1) malfunction
Mass air flow meter
Engine coolant temp. sensor
Gas leakage on exhaust system
HINT:
When DTC P0171 is recorded, the actual air±fuel ratio is on the LEAN side. When DTC P0172 is re-
corded, 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 is recorded. The MIL then
comes on.
If the total of the short±term fuel trim value and long±term fuel trim value is within + 35 % (80°C (176°F)
or more), the system is functioning normally.
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 warmed up or not, the air±fuel ratio lean or rich, etc.
at the time of the malfunction.
DI4DR±01
DI±276
± DIAGNOSTICSENGINE (1MZ±FE)
511 Author: Date:
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 revolutionsIgnition system
Injector
Fuel line pressure
P0301
P0302
P0303For any particular 200 revolutions for engine, misfiring is de-
tected which can cause catalyst overheating
(This causes MIL to blink)
EGR
Compression pressure
Valve clearance not to specification
Valve timing
Mass air flow meterP0303
P0304
P0305
P0306For any particular 1,000 revolutions of engine, misfiring is de-
tected which causes a deterioration in emission
(2 trip detection logic)
Mass air flow meter
Engine coolant temp. sensor
Open or short in engine wire
Connector connection
ECM
DI07S±07
A07449
Fusible
Link
Block
FL
MAINStop Light Switch
B±G1B 1CSTOP
WG±WLight
Failure
Sensor 7
2
To Stop Light Instrument Panel J/B
Instrument Panel J/B
E7 15
G±W
1S 1R
1R1
2
F9
F4
BatteryECM
STP
E1 B±R
ALT
G±WA
C
J27Junction
Connector
J2845
2
G±W7 4
1
1
± DIAGNOSTICSENGINE (1MZ±FE)
DI±363
598 Author: Date:
DTC P1520 Stop Light Switch Signal Malfunction
(Only for A/T)
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 the driving at
30 km or more 10 times or more after depressing brake
(2 trip detection logic)Short in stop light switch signal circuit
Stop light switch
ECM
WIRING DIAGRAM
DI088±06
A02037
ON
ON
Brake Pedal
DepressedBrake Pedal
Released
STP (+)
DI±364
± DIAGNOSTICSENGINE (1MZ±FE)
599 Author: Date:
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 warmed up or not, the air±fuel ratio 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.
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 pedal is depressed: STP ...... ON
Brake pedal is released: STP ...... OFF
When not using TOYOTA hand±held tester:
PREPARATION:
Turn the ignition switch ON.
CHECK:
Check 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±197).
NG
DI02W±02
FI0534
S05335
TOYOTA hand±held tester
DLC3
± DIAGNOSTICSAUTOMATIC TRANSAXLE (A140E)
DI±389
624 Author: Date:
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 an OBD II scan tool complying
with SAE J1987 or TOYOTA hand±held tester to the
vehicle, 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 computer itself or
in drive system components which affect vehicle
emissions. In addition to the MIL lighting up when
a malfunction is detected, the applicable DTCs pre-
scribed by SAE J2012 are recorded in the ECM
memory (See page DI±16).
If the malfunction only occurs in 3 trips, the MIL goes
off but the DTCs remain recorded in the ECM
memory.
To check the DTCs, connect an OBD II scan tool or
TOYOTA hand±held tester to DLC3 on the vehicle.
The OBD II scan tool or TOYOTA hand±held tester
also enables you to erase the DTCs and check
freeze frame data and various forms of engine data
(For instruction book).
DTCs include SAE controlled codes and Manufac-
turer controlled codes.
SAE controlled codes must be set as the codes pre-
scribed by the SAE, while Manufacturer controlled
codes can be set freely by the manufacturer within
the prescribed limits.
(See DTC chart on page DI±401)
D01810
: w/ Engine Immobiliser System
: w/o Engine Immobiliser System
: O/D Main Switch
Contacts go open with switch pushed in
Contacts go closed with switch pushed once againInstrument
Panel J/BIgnition Switch
1B1
AM1
W
I16
7 1
22
1K2
AM1 IG1
B ± Y
O/D OFF
Indicator Light
(Combination Meter) R ± L
R ± LGAUGE
J4
Junction
Connector
DI164
2
1D 1K
D12
C8G ± OC
C8
W ± B C
CG ± O
G ± OJ6
Junction
ConnectorECM
5
*1B+
E77*2
E7OD2G ± O
IG311
O2 2
(*3)
O/D Main
Switch
O2
4
W ± B A
IF AJ5
Junction
Connector B ± R
1
FUSIBLE
LINK
BLOCKALT F9B ± R
2
F9
1
F4B ± GFL
MAIN
Battery
*3 *2 *1
1 Instrument
Panel J/B
± DIAGNOSTICSAUTOMATIC TRANSAXLE (A140E)
DI±431
666 Author: Date:
O/D Main Switch & O/D OFF Indictor Light Circuit
CIRCUIT DESCRIPTION
The O/D main switch contacts go open when the switch is pushed in and go closed when it is pushed out.
In O/D main switch in OFF position, the O/D OFF indicator light lights up, and the ECM prohibits shifting over-
drive.
WIRING DIAGRAM
DI1J1±01