DI±162
± DIAGNOSTICSENGINE (5S±FE)
397 Author: Date:
2 Check resistance of A/F sensor heater (See page SF±59).
NG Replace A/F sensor.
OK
Check and repair harness or connector between EFI main relay (Marking: EFI) and A/F sensor,
and A/F sensor and ECM (See page IN±31).
DI±202
± DIAGNOSTICSENGINE (1MZ±FE)
437 Author: Date:
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 temperature is fixed at 20°C (68°F)Returned to normal condition
P0115Engine coolant temperature 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
consecutively
(a) Vehicle speed: 0km/h (0mph)
(b) VTA 0.1 V and 0.95 V
P0135
P0141
P0155The heater circuit in which an abnormality is detected is
turned offIgnition switch OFF
P0325
P0330Max. timing retardationIgnition switch OFF
P1300Fuel cutIGF signal is detected for 6 consecutive ignition
5. CHECK FOR INTERMITTENT PROBLEMS
TOYOTA HAND±HELD TESTER only:
By putting the vehicle's ECM in 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 page DI±197).
(2) Set the check mode (See page DI±197).
(3) Perform a simulation test (See page IN±21).
(4) Check the connector and terminal (See page IN±31).
(5) Handle the connector (See page IN±31).
6. BASIC INSPECTION
When the malfunction code is not confirmed in the DTC check, troubleshooting should be performed in the
order for all possible circuits to be considered as the causes 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
DI±212
± DIAGNOSTICSENGINE (1MZ±FE)
447 Author: Date:
DTC No.
(See Page)Detection ItemTrouble AreaMILMemory
*2
P0133
(DI±259)
Heated Oxygen Sensor Circuit
Slow Response
(Bank 1 Sensor 1)Heated oxygen sensor
Fuel trim malfunction
*2
P0135
(DI±263)
Heated Oxygen Sensor Heater
Circuit Malfunction
(Bank 1 Sensor 1)Open or short in heater circuit of heated oxygen sensor
Heated oxygen sensor heater
ECM
P0136
(DI±265)Heated Oxygen Sensor Circuit
Malfunction
(Bank 1 Sensor 2)
Heated oxygen sensor
P0141
(DI±263)Heated Oxygen Sensor Heater
Circuit Malfunction
(Bank 1 Sensor 2)
Same as DTC No. P0135*1
*3
P0150
(DI±255)
Heated Oxygen Sensor
Circuit Malfunction
(Bank 2 Sensor 1)
Same as DTC No. P0130*1
*3
P0153
(DI±259)
Heated Oxygen Sensor
Circuit Slow Response
(Bank 2 Sensor 1)Same as DTC No. P0133
Fuel trim malfunction*1
*3
P0155
(DI±263)Heated Oxygen Sensor
Circuit Malfunction
(Bank 2 Sensor 1)
Same as DTC No. P0135*1
*3
P0171
(DI±272)System too Lean
(Fuel Trim)
(Except California Spec.)
Air intake (hose loose)
Fuel line pressure
Injector blockage
Heated oxygen sensor (bank 1, 2 sensor 1) malfunction
Mass air flow meter
Engine coolant temp. sensor
Gas leakage on exhaust system
*1
*3
P0172
(DI±272)System too Rich
(Fuel Trim)
(Except California Spec.)
Fuel line pressure
Injector leak, blockage
Heated oxygen sensor (bank 1, 2 sensor 1) malfunction
Mass air flow meter
Engine coolant temp. sensor
Gas leakage on exhaust system
*1
*4
P0171
(DI±267)System too Lean
(Fuel Trim)
(Only for California Spec.)
Air intake (hose loose)
Fuel line pressure
Injector blockage
Mass air flow meter
Engine coolant temp. sensor
A/F sensor (bank 1, 2 sensor 1)
Gas leakage on exhaust system
*1
*4
P0172
(DI±267)System too rich
(Fuel Trim)
(Only for California Spec.)
Fuel line pressure
Injector leak, blockage
Heated oxygen sensor malfunction
Mass air flow meter
Engine coolant temp. sensor
A/F sensor (bank 1, 2 sensor 1)
Gas leakage on exhaust system
*1
*1: MIL lights up
*2: MIL light up or blinking
*3: Except California specification vehicles
*4: Only for California specification vehicle
± 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
P21242 FI7210
A00027
Atmosphere
CoverIdeal Air±Fuel Mixture
Air Fuel Ratio
RicherLeaner
Exhaust GasFlange
Platinum Electrode
Solid Electrolyte
(Zirconia Element)
Platium Electrode
Heater
Coating(Ceramic)
Output Voltage
DI±244
± DIAGNOSTICSENGINE (1MZ±FE)
479 Author: Date:
DTC P0125 Insufficient Coolant Temp. for Closed Loop
Fuel Control (Except California Spec.)
CIRCUIT DESCRIPTION
To obtain a high purification rate for the CO, HC and NOx components of the exhaust gas, a three±way
catalytic converter is used, but for the most efficient use of the three±way catalytic converter, the air±fuel
ratio must be precisely controlled so that it is always close to the stoichiometric air±fuel ratio.
The oxygen sensor has the characteristic whereby its output voltage changes suddenly in the vicinity of the
stoichiometric air±fuel ratio. This characteristic is used to detect the oxygen concentration in the exhaust
gas and provide feedback to the computer for control of the air±fuel ratio.
When the air±fuel ratio becomes LEAN, the oxygen concentration in the exhaust increases and the oxygen
sensor informs the ECM of the LEAN condition (small electromotive force: < 0.45 V).
When the air±fuel ratio is RICHER than the stoichiometric air±fuel ratio the oxygen concentration in the ex-
haust gas is reduced and the oxygen sensor informs the ECM of the RICH condition (large electromotive
force: > 0.45 V). The ECM judges by the electromotive force from the oxygen sensor whether the air±fuel
ratio is RICH or LEAN and controls the injection time accordingly. However, if malfunction of the oxygen sen-
sor causes output of abnormal electromotive force, the ECM is unable to perform accurate air±fuel ratio con-
trol.
The heated oxygen sensors include a heater which heats the zirconia element. The heater is controlled by
the ECM. When the intake air volume is low (the temperature of the exhaust gas is low) current flows to the
heater to heat the sensor for accurate oxygen concentration detection.
DTC No.DTC Detecting ConditionTrouble Area
P0125
After engine is warmed up, heated oxygen sensor (bank 1, 2
sensor 1) output does not indicate RICH ( 0.45 V ) even
once when conditions (a), (b), (c) and (d) continue for at least
2 min.:
(a) Engine speed: 1,500 rpm or more
(b) Vehicle speed: 40 SPD and 100 km/h (25 SPD and
62 mph)
(c) Throttle valve does not fully closed
(d) 140 sec. or more after starting engineFuel system
Injector
Ignition system
Gas leakage on exhaust system
Open or short in heated oxygen sensors (bank 1, 2 sensor 1)
circuit
Heated oxygen sensors (bank 1, 2 sensor 1)
ECM
DI07M±08
A00477
CoverAtmosphere
Platinum
Electrode
Solid Electrolyte
(Zirconia Element)
Platinum
Electrode
Heater
Coating (Ceramic)
Exhaust Gas
(V)
4.0
3.8
3.6
3.4
3.2
3.0
2.8
2.6
17
Air±Fuel Ratio
2.4
16 15 12 1413 1918ECM Monitored
A/F Sensor Voltage
± DIAGNOSTICSENGINE (1MZ±FE)
DI±249
484 Author: Date:
DTC P0125 Insufficient Coolant Temp. for Closed Loop
Fuel Control (Only for California Spec.)
CIRCUIT DESCRIPTION
To obtain a high purification rate for the CO, HC and NOx components of the exhaust gas, a three±way
catalytic converter is used, but for the most efficient use of the three±way catalytic converter, the air±fuel
ratio must be precisely controlled so that it is always close to the stoichiometric air±fuel ratio.
The A/F sensor has the characteristic that provides output voltage
* approximately proportional to the existing
air±fuel ratio. The A/F sensor output voltage
* is used to provide feedback for the ECM to control the air±fuel
ratio.
By the A/F sensor output, the ECM can determine the deviation amount from the stoichiometric air±fuel ratio
and control the proper injection time immediately. If the A/F sensor is malfunctioning, ECM is unable to per-
form accurate air±fuel ratio control.
The A/F sensor is equipped with a heater which heats the zirconia element. The heater is controlled by the
ECM. When the intake air volume is low (the temp. of the exhaust gas is low), current flows to the heater
to heat the sensor for accurate oxygen concentration detection.
*: The voltage value changes at the inside of the ECM only.
DTC No.DTC Detecting ConditionTrouble Area
P0125
After engine is warmed up, A/F sensor output* does not
change when conditions (a), (b) and (c) continue for at least
1.5 min.
*: Output value changes at inside of ECM only.
(a) Engine speed: 1,500 rpm or more
(b) Vehicle speed: 40 ~ 100 km/h (25 ~ 62 mph)
(c) Throttle valve does not fully closed
(d) After starting engine 140 secFuel system
Injector
Ignition system
Gas leakage on exhaust system
Open or short in A/F sensor circuit (bank 1, 2 sensor 1)
A/F sensors (bank 1, 2 sensor 1)
ECM
DI07M±09
± DIAGNOSTICSENGINE (1MZ±FE)
DI±253
488 Author: Date:
4 Check resistance of A/F sensor heaters (bank1, 2 sensor1) (See page SF±68).
NG Replace A/F sensor.
OK
5 Check air induction system (See page SF±1).
NG Repair or replace.
OK
6 Check EGR system (See page EC±11).
NG Replace EGR system.
OK
7 Check fuel pressure (See page SF±21).
NG Check and repair fuel pump, fuel pipe line and
filter (See page SF±1).
OK
8 Check injector injection (See page SF±25).
NG Replace injector.
OK
± DIAGNOSTICSENGINE (1MZ±FE)
DI±263
498 Author: Date:
DTC P0135 Heated Oxygen Sensor Heater Circuit Mal-
function (Bank 1 Sensor 1) (EX. CA Spec.)
DTC P0141 Heated Oxygen Sensor Heater Circuit Mal-
function (Bank 1 Sensor 2)
DTC P0155 Heated Oxygen Sensor Heater Circuit Mal-
function (Bank 2 Sensor 1) (EX. CA Spec.)
CIRCUIT DESCRIPTION
Refer to DTC P0125 (Insufficient Coolant Temp. for Closed Loop Fuel Control (Except California Spec.)) on
page DI±244.
DTC No.DTC Detecting ConditionTrouble Area
P0135
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 htP0141
P0155Heater 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.
Bank 2 refers to the bank that does not include cylinder No.1.
Sensor 1 refers to the sensor closer to the engine body.
Sensor 2 refers to the sensor farther away from the engine body.
WIRING DIAGRAM
Refer to DTC P0125 (Insufficient Coolant Temp. for Closed Loop Fuel Control (Except California Spec.))
on page DI±244.
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.
DI07P±06