FI6448
Engine Coolant Temp. SensorECM
5V
THW
E2
E1 2
1G±B
BR
E10
14
18
E10
± DIAGNOSTICSENGINE (1MZ±FE)
DI±233
468 Author: Date:
DTC P0115 Engine Coolant Temp. Circuit Malfunction
CIRCUIT DESCRIPTION
A thermistor built into the engine coolant temp. sensor changes the resistance value according to the engine
coolant temp.
The structure of the sensor and connection to the ECM is the same as in the intake air temp. circuit malfunc-
tion shown on page DI±228.
If the ECM detects the DTC P0115, it operates fail±safe function in which the engine coolant temperature
is assumed to be 80°C (176°F).
DTC No.Detection ItemTrouble Area
P0115Open or short in engine coolant temp. sensor circuit
Open or short in engine coolant temp. sensor circuit
Engine coolant temp. sensor
ECM
HINT:
After confirming DTC P0115, use the OBD II scan tool or TOYOTA hand±held tester to confirm the engine
coolant temp. from CURRENT DATA.
Temperature DisplayedMalfunction
±40°C (±40°F)Open circuit
140°C (284°F) or moreShort circuit
WIRING DIAGRAM
INSPECTION PROCEDURE
HINT:
If DTCs P0110 (Intake Air Temp. Circuit Malfunction), P0115 (Engine Coolant Temp. Circuit Malfunc-
tion), P0120 (Throttle/Pedal/Position Sensor/Switch ºAº Circuit Malfunction) and P1410 (EGR Valve
Position Sensor Circuit Malfunction) are output simultaneously, E2 (Sensor Ground) may be open.
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.
DI07I±06
P24296
ECM
Throttle Position
Sensor
VC
VTA1
E2
S05019
ECM
1
3
25 V
VC
VTA1
E2 Y
L
BR Throttle Position Sensor
E102
23
18 E10
E10
± DIAGNOSTICSENGINE (1MZ±FE)
DI±239
474 Author: Date:
DTC P0120 Throttle/Pedal Position Sensor/Switch ºAº
Circuit Malfunction
CIRCUIT DESCRIPTION
The throttle position sensor is mounted in the throttle body and
detects the throttle valve opening angle. When the throttle valve
is fully closed, a voltage of approximately 0.7 V is applied to ter-
minal VTA of the ECM. The voltage applied to the terminals VTA
of the ECM increases in proportion to the opening angle of the
throttle valve and becomes approximately 2.7 ~ 5.2 V when the
throttle valve is fully opened. the ECM judges the vehicle driving
conditions from these signals input from terminals VTA and
uses them as one of the conditions for deciding the air±fuel ratio
correction, power increase correction and fuel±cut control etc.
DTC No.DTC Detecting ConditionTrouble Area
P0120
Condition (a) or (b) continues:
(a) VTA
0.1 V
(b) VTA
4.9 V
Open or short in throttle position sensor circuit
Throttle position sensor
ECM
HINT:
After confirming DTC P0120, use the OBD II scan tool or TOYOTA hand±held tester to confirm the throttle
valve opening percentage and closed throttle position switch condition.
Throttle valve opening position
expressed as percentage
Trouble Area
Throttle valve fully closedThrottle valve fully open
Trouble Area
0 %0 %VC line open
VTA line open or short
Approx. 100 %Approx. 100 %E2 line open
WIRING DIAGRAM
DI07K±06
A07444
BatteryJunction Connector
MREL
ECM
B
B+
E1
E03
E03
E1E1
E03 OXL1
HTL1
OXR1
HTR
OXS
HTS
E8E8 E10 E11E7
E10
E10
E108
12
4
11
30
3
8
9
Y±R
3
2
4
1
W
BR
L±B
B
BR
3 2
4
1
B±Y
B±Y
B±Y
A A B Junction Connector
B
J28 J27
J27 B±YJunction Connector
2K
2J
3
1
2
5
EFI
2C 2A 1 5
F6
F4 1
1
B
W±B
EB
FL
MAINFusible
Link
Block
E03
Engine
Room
J/B
B±G
Heated Oxygen
Sensor
(Bank 1 Sensor 2)3
2
1
EDEC
P±BA
A
BR
BR4 B±YHeated Oxygen
Sensor
(Bank 1 Sensor 1)II3 B±WAC
J36 J35B±W
EFI Relay
BR
BR
2 7B±Y9
Heated Oxygen
Sensor
(Bank 2 Sensor 1)
D
± DIAGNOSTICSENGINE (1MZ±FE)
DI±245
480 Author: Date:
HINT:
After confirming DTC P0125, use the OBD II scan tool or TOYOTA hand-held tester to confirm voltage output
of the heated oxygen sensors (bank 1, 2 sensor 1) from CURRENT DATA.
If voltage output of the heated oxygen sensors (bank 1, 2 sensor 1) is less than 0.1 V, heated oxygen sensors
(bank 1, 2 sensor 1) circuit may be open or short.
WIRING DIAGRAM
INSPECTION PROCEDURE
HINT:
If the vehicle run out fuel, the air±fuel ratio is LEAN and DTC P0125 will be recorded.
The MIL then comes on.
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.
A07445
B
BB B
2 142
31 23
4
BR
23
1
B±W P±BB B±WB±R
*
1L
E8 E8 E10 E10
E78 9 84 213 122011
AFR+
AFR±
AFL+
AFL± HAFR
OXS
HTS
MREL HAFLECM
3.3 V
3.3 V 3.0 V
3.0 V
E1
B+ E10 E10E10E10 1
J27
Engine Room J/B
F6
F4 2J
2A
2C2K
2
7
5 1
EFI Relay
1
1B
B±W
B±W
B EFI
1 2
2
52
22 3
L W±B1
1 2
A/F HTR
1
W
FL
MAIN FLEngine RoomBattery*
1B±W B
B
B±G
1
2 3
5
E04
E05
E03
*1B±R *1BR *G
*G
*B±W*L
ES1
J27 B
E
Junction
connector
A/F Sensor
(Bank 2, Sensor 1)
B±Y
A/F Sensor
(Bank 1, Sensor 2)
BRII1A
ABR
J22
Junction
Connector J24
Junction
Connector
B±Y
W±B
B±W
J35
J35J36A C
C
EB EC
A/F Sensor
(Bank 1, Sensor 1)
Engine Room
A/F HTR Relay
*: TMC Made
*: TMMK Made
Junction
Connector
4
to Analog±Digital
Converter
to Analog±Digital
Converter
DI±250
± DIAGNOSTICSENGINE (1MZ±FE)
485 Author: Date:
HINT:
After confirming DTC P0125, use the OBD II scan tool or TOYOTA hand-held tester to confirm voltage
output of heated oxygen sensors (bank 1, 2 sensor 1) from CURRENT DATA.
The ECM controls the voltage of AFR, AFL, AFR and AFL terminals of ECM to the fixed volt-
age. Therefore, it is impossible to confirm the A/F sensor output voltage without OBD II scan tool or
TOYOTA hand±held tester.
OBD II scan tool (excluding TOYOTA hand±held tester) displays the one fifth of the A/F sensor output
voltage which is displayed on the TOYOTA hand±held tester.
WIRING DIAGRAM
A01666
Vehicle speed
50 ~ 65 km/h
(31 ~ 40 mph)
(5)Idling
IG SW OFF
1 ~ 3 min. 1 min.Time
(2)
(1)(3)(4)
± DIAGNOSTICSENGINE (1MZ±FE)
DI±255
490 Author: Date:
DTC P0130 Heated Oxygen Sensor Circuit Malfunction
(Bank 1 Sensor 1) (Except California Spec.)
DTC P0150 Heated Oxygen Sensor Circuit Malfunction
(Bank 2 Sensor 1) (Except California Spec.)
CIRCUIT DESCRIPTION
Refer to DTC P0125 (Insufficient Coolant Temp. for Closed Loop Fuel Control) on page DI±244.
DTC No.DTC Detecting ConditionTrouble Area
P0130
P0150Voltage output of heated oxygen sensor remains at 0.4 V or
more, or 0.55 V or less, during idling after engine is warmed up
(2 trip detection logic)Heated oxygen sensor
Fuel trim malfunction
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.
The heated oxygen sensor's output voltage and the short-term fuel trim value can be read using the
OBD II scan tool or TOYOTA hand-held tester.
WIRING DIAGRAM
Refer to DTC P0125 (Insufficient Coolant Temp. for Closed Loop Fuel Control) on page DI±244.
CONFIRMATION DRIVING PATTERN
(1) Connect the TOYOTA hand±held tester to the DLC3.
(2) Switch the TOYOTA hand±held tester from normal mode to check mode (See page DI±197).
(3) Start the engine and warm it up with all accessory switches OFF.
(4) Drive the vehicle at 50 ~ 65 km/h (31 ~ 40 mph) for 1 ~ 3 min. to warm up the heated oxygen sensor.
(5) Let the engine idle for 1 min.
(6) Perform steps (3) to (5) three times.
DI07N±07
± 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
± DIAGNOSTICSENGINE (1MZ±FE)
DI±265
500 Author: Date:
DTC P0136 Heated Oxygen Sensor Circuit Malfunction
(Bank 1 Sensor 2)
CIRCUIT DESCRIPTION
Refer to DTC P0125 (Insufficient Coolant Temp. for Closed Loop Fuel Control) on page DI±244.
DTC No.DTC Detecting ConditionTrouble Area
P0136
Voltage output of heated oxygen sensor (bank 1 sensor 2)
remains at 0.4 V or more or 0.6*1 0.5*2 V or less when vehicle
is driven at 50 km/h (31 mph) or more after engine is warmed
up
*
1: for California Spec.
*2: except California Spec.
(2 trip detection logic)
Heated oxygen sensor
HINT:
Bank 1 refers to the bank that includes cylinder No.1. 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) 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.
1 Are there any other codes (besides DTC P0136) being output ?
YES Go to relevant DTC chart.
NO
2 Check for open and short in harness and connector between ECM and heated
oxygen sensor (See page IN±31).
NG Repair or replace harness or connector.
OK
DI07Q±06
A03319
Instrument
Panel J/B
Engine
Room
J/B
N0.2
BatteryFL
MAINB±GB±R B±R
B±R
W±RJ18
Junction
Connector
B±R
B±R
B±R
B±R
B±R
B±R2
2
2
2
2
21
1
1
1
1
1L
R
Y
W
R±L
GE10
Ignition
Switch
No. 1
No. 2
No. 3
No. 4
No. 5
No. 6
Injector
BR
BR
EC
II3
5
6
21
311
2
3
4#10
#20
#30
#40
#50
#60
E01
E02ECM
12
2L
2A
AM2
4
1
B
F4F6 11 6
7
1K 1K 1C
1B 38
55
W±RE10
E11
E11
E11
E11
E11
E11 Fusible
Link
Block
± DIAGNOSTICSENGINE (1MZ±FE)
DI±277
512 Author: Date:
HINT:
When the 2 or more codes for a misfiring cylinder are recorded repeatedly but no Random Misfire code is
recorded, it indicates that the misfires were detected and recorded at different times.
WIRING DIAGRAM
CONFIRMATION DRIVING PATTERN
(1) Connect the TOYOTA hand±held tester or OBD II scan tool.
(2) Record DTC and the freeze frame data.
(3) Use the TOYOTA hand±held tester to set to Check Mode. (See page DI±197)
(4) Drive the vehicle several times with the engine speed, load and its surrounding range shown with
ENGINE SPD, CALC LOAD in the freeze frame data or MISFIRE RPM, MISFIRE LOAD in the data list.
If you have no TOYOTA hand±held tester, turn the ignition switch OFF after the symptom is simulated
the first time. Then repeat the simulation process again.
HINT:
In order to memorize DTC of misfire, it is necessary to drive around MISFIRE RPM, MISFIRE LOAD in the
data list for the following period of time.
Engine SpeedTime
Idling3 minutes 30 seconds or more
1000 rpm3 minutes or more
2000 rpm1 minute 30 seconds or more
3000 rpm1 minute or more
(5) Check whether there is misfire or not by monitoring DTC and the freeze frame data. After that, record
them.
(6) Turn ignition switch OFF and wait at least 5 seconds.