2008 NISSAN LATIO heater

EC-154
< SERVICE INFORMATION >
DTC P0031, P0032 A/F SENSOR 1 HEATER
1. Disconnect air fuel ratio (A/F) sensor 1 harness connector (1).
2. Turn ignition switch ON.
- Air fuel ratio (A/F) sensor 1 (2)
3. Check voltage between A/F sensor 1 terminal 4 and ground with
CONSULT-II or tester.
OK or NG
OK >> GO TO 4.
NG >> GO TO 3.
3.DETECT MALFUNCTIONING PART
Check the following.
• Harness connectors E8, F8
• Harness for open or short between A/F sensor 1 and fuse
>> Repair or replace harness or connectors.
4.CHECK A/F SENSOR 1 HEATER OUTPUT SIGNAL CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check harness continuity between ECM terminal 3 and A/F sensor 1 terminal 3.
Refer to Wiring Diagram.
4. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 5.
NG >> Repair open circuit or short to ground or short to power in harness or connectors.
5.CHECK A/F SENSOR 1 HEATER
Refer to EC-154, "
Component Inspection".
OK or NG
OK >> GO TO 6.
NG >> Replace air fuel ratio (A/F) sensor 1.
6.CHECK INTERMITTENT INCIDENT
Perform EC-136
.
>>INSPECTION END
Component InspectionINFOID:0000000001702630
AIR FUEL RATIO (A/F) SENSOR 1 HEATER
BBIA0699E
Voltage: Battery voltage
PBIB3308E
Continuity should exist.

DTC P0031, P0032 A/F SENSOR 1 HEATER
EC-155
< SERVICE INFORMATION >
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1. Check resistance between A/F sensor 1 terminals as follows.
2. If NG, replace air fuel ratio (A/F) sensor 1.
CAUTION:
• Discard any A/F sensor which has been dropped from a
height of more than 0.5 m (19.7 in) onto a hard surface such
as a concrete floor; use a new one.
• Before installing new A/F sensor, clean exhaust system
threads using Heated Oxygen Sensor Thread Cleaner tool J-
43897-18 or J-43897-12 and approved anti-seize lubricant.
Removal and InstallationINFOID:0000000001702631
AIR FUEL RATIO SENSOR HEATER
Refer to EM-21.
Terminal No. Resistance
3 and 4 1.8 - 2.44 Ω [at 25°C (77°F)]
3 and 1, 2
∞ Ω
(Continuity should not exist)
4 and 1, 2
PBIB3309E

EC-156
< SERVICE INFORMATION >
DTC P0037, P0038 HO2S2 HEATER
DTC P0037, P0038 HO2S2 HEATER
DescriptionINFOID:0000000001702632
SYSTEM DESCRIPTION
The ECM performs ON/OFF control of the heated oxygen sensor 2 heater corresponding to the engine speed,
amount of intake air and engine coolant temperature.
OPERATION
CONSULT-II Reference Value in Data Monitor ModeINFOID:0000000001702633
Specification data are reference values.
On Board Diagnosis LogicINFOID:0000000001702634
DTC Confirmation ProcedureINFOID:0000000001702635
NOTE:
If DTC Confirmation Procedure has been previously conducted, always turn ignition switch OFF and wait at
least 10 seconds before conducting the next test.
TESTING CONDITION:
Before performing the following procedure, confirm that battery voltage is between 10.5V and 16V at
idle.
WITH CONSULT-II
Sensor Input Signal to ECM ECM Function Actuator
Camshaft position sensor (PHASE)
Engine speed
Heated oxygen sensor 2
heater controlHeated oxygen sensor 2 heater Crankshaft position sensor (POS)
Engine coolant temperature sensorEngine coolant tempera-
ture
Mass air flow sensor Amount of intake air
Engine speed rpm Heated oxygen sensor 2 heater
Above 3,600OFF
• Below 3,600 rpm after the following conditions are met.
- Engine: After warming up
- Keeping the engine speed between 3,500 and 4,000 rpm for 1
minute and at idle for 1 minute under no loadON
MONITOR ITEM CONDITION SPECIFICATION
HO2S2 HTR (B1)• Engine speed: Below 3,600 rpm after the following conditions are met
- Engine: After warming up
- Keeping the engine speed between 3,500 and 4,000 rpm for 1 minute and
at idle for 1 minute under no load.ON
• Engine speed: Above 3,600 rpm OFF
DTC No.Trouble diagnosis
nameDTC detecting condition Possible cause
P0037
0037Heated oxygen
sensor 2 heater
control circuit lowThe current amperage in the heated oxygen sensor
2 heater circuit is out of the normal range.
(An excessively low voltage signal is sent to ECM
through the heated oxygen sensor 2 heater.)• Harness or connectors
(Heated oxygen sensor 2 heater circuit is
open or shorted.)
• Heated oxygen sensor 2 heater
P0038
0038Heated oxygen
sensor 2 heater
control circuit highThe current amperage in the heated oxygen sensor
2 heater circuit is out of the normal range.
(An excessively high voltage signal is sent to ECM
through the heated oxygen sensor 2 heater.)• Harness or connectors
(Heated oxygen sensor 2 heater circuit is
shorted.)
• Heated oxygen sensor 2 heater

DTC P0037, P0038 HO2S2 HEATER
EC-157
< SERVICE INFORMATION >
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1. Turn ignition switch ON and select “DATA MONITOR” mode with CONSULT-II.
2. Start engine and warm it up to the normal operating temperature.
3. Turn ignition switch OFF and wait at least 10 seconds.
4. Start engine and keep the engine speed between 3,500 and
4,000 rpm for at least 1 minute under no load.
5. Let engine idle for 1 minute.
6. If 1st trip DTC is detected, go to EC-159, "
Diagnosis Procedure".
WITH GST
Follow the procedure “WITH CONSULT-II” above.
SEF174Y

EC-158
< SERVICE INFORMATION >
DTC P0037, P0038 HO2S2 HEATER
Wiring Diagram
INFOID:0000000001702636
Specification data are reference values and are measured between each terminal and ground.
Pulse signal is measured by CONSULT-II.
CAUTION:
BBWA2628E

DTC P0037, P0038 HO2S2 HEATER
EC-159
< SERVICE INFORMATION >
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Do not use ECM ground terminals when measuring input/output voltage. Doing so may result in dam-
age to the ECM's transistor. Use a ground other than ECM terminals, such as the ground.
: Average voltage for pulse signal (Actual pulse signal can be confirmed by oscilloscope.)
Diagnosis ProcedureINFOID:0000000001702637
1.CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten ground screw on the body.
Refer to EC-142, "
Ground Inspection".
OK or NG
OK >> GO TO 2.
NG >> Repair or replace ground connections.
2.CHECK HO2S2 POWER SUPPLY CIRCUIT
TER-
MI-
NAL
NO.WIRE
COLORITEM CONDITION DATA (DC Voltage)
5GHeated oxygen sensor 2
heater[Engine is running]
• Engine speed: Below 3,600 rpm after the fol-
lowing conditions are met.
- Engine: After warming up
- Keeping the engine speed between 3,500
and 4,000 rpm for 1 minute and at idle for 1
minute under no load.Approximately 10V
[Ignition switch: ON]
• Engine stopped
[Engine is running]
• Engine speed: Above 3,600 rpm.BATTERY VOLTAGE
(11 - 14V)
50 W Heated oxygen sensor 2[Engine is running]
• Revving engine from idle to 3,000 rpm quick-
ly after the following conditions are met.
- Engine: After warming up
- Keeping the engine speed between 3,500
and 4,000 rpm for 1 minute and at idle for 1
minute under no load.0 - Approximately 1.0V
59 OSensor ground
(Heated oxygen sensor 2)[Engine is running]
•Warm-up condition
• Idle speedApproximately 0V
PBIA8148J
:Vehicle front
1. Body ground E24 2. Engine ground F9 3. Engine ground F16
4. Body ground E15
BBIA0698E

EC-160
< SERVICE INFORMATION >
DTC P0037, P0038 HO2S2 HEATER
1. Disconnect heated oxygen sensor 2 harness connector (2).
- : Vehicle front
- Heated oxygen sensor 2 (1)
2. Turn ignition switch ON.
3. Check voltage between HO2S2 terminal 2 and ground with
CONSULT-II or tester.
OK or NG
OK >> GO TO 4.
NG >> GO TO 3.
3.DETECT MALFUNCTIONING PART
Check the following.
• Harness connectors E8, F8
• Harness for open or short between heated oxygen sensor 2 and fuse
>> Repair open circuit or short to ground or short to power in harness or connectors.
4.CHECK HO2S2 OUTPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check harness continuity between ECM terminal 5 and HO2S2 terminal 3.
Refer to Wiring Diagram.
4. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 5.
NG >> Repair open circuit or short to ground or short to power in harness or connectors.
5.CHECK HEATED OXYGEN SENSOR 2 HEATER
Refer to EC-160, "
Component Inspection".
OK or NG
OK >> GO TO 6.
NG >> Replace heated oxygen sensor 2.
6.CHECK INTERMITTENT INCIDENT
Refer to EC-136
.
>>INSPECTION END
Component InspectionINFOID:0000000001702638
HEATED OXYGEN SENSOR 2 HEATER
BBIA0700E
Voltage: Battery voltage
MBIB0186E
Continuity should exist.

DTC P0037, P0038 HO2S2 HEATER
EC-161
< SERVICE INFORMATION >
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1. Check resistance between HO2S2 terminals as follows.
2. If NG, replace heated oxygen sensor 2.
CAUTION:
• Discard any heated oxygen sensor which has been dropped
from a height of more than 0.5 m (19.7 in) onto a hard surface
such as a concrete floor; use a new one.
• Before installing new oxygen sensor, clean exhaust system
threads using Oxygen Sensor Thread Cleaner tool J-43897-18
or J-43897-12 and approved anti-seize lubricant.
Removal and InstallationINFOID:0000000001702639
HEATED OXYGEN SENSOR 2
Refer to EM-21.
Terminal No. Resistance
2 and 3 3.4 - 4.4 Ω [at 25°C (77°F)]
1 and 2, 3, 4
∞ Ω
(Continuity should not exist)
4 and 1, 2, 3
PBIB3310E