Nissan Qashqai (2007-2010). Manual — part 163

P0141 HO2S2 HEATER

EC-171

< COMPONENT DIAGNOSIS >

[HR16DE (WITH EURO-OBD)]

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P0141 HO2S2 HEATER

Description

INFOID:0000000001056186

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

DTC Logic

INFOID:0000000001056187

DTC DETECTION LOGIC

DTC CONFIRMATION PROCEDURE

1.

PRECONDITIONING

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 more than 11V at idle.

>> GO TO 2.

2.

PERFORM DTC CONFIRMATION PROCEDURE

With CONSULT-III

1.

Turn ignition switch ON and select “DATA MONITOR” mode with CONSULT-III.

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.

Check 1st trip DTC.

With GST

Follow the procedure “With CONSULT-III” above.
Is 1st tip DTC detected?

YES

>> Go to

EC-172, "Diagnosis Procedure"

.

NO

>> INSPECTION END

Sensor

Input signal to ECM

ECM function

Actuator

Camshaft position sensor (PHASE)
Crankshaft position sensor (POS)

Engine speed

Heated oxygen sensor 2
heater control

Heated oxygen sensor 2 heater

Engine coolant temperature sensor

Engine coolant temperature

Mass air flow sensor

Amount of intake air

Engine speed rpm

Heated oxygen sensor 2 heater

Above 3,900

OFF

Below 3,900 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

DTC No.

Trouble diagnosis

name

DTC detecting condition

Possible cause

P0141

Heated oxygen
sensor 2 heater
control circuit low

The current amperage in the heated oxygen sen-
sor 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

(The heated oxygen sensor 2 heater circuit is
open or shorted.)

• Heated oxygen sensor 2 heater

EC-172

< COMPONENT DIAGNOSIS >

[HR16DE (WITH EURO-OBD)]

P0141 HO2S2 HEATER

Diagnosis Procedure

INFOID:0000000001056188

1.

CHECK GROUND CONNECTION

1.

Turn ignition switch OFF.

2.

Check ground connection E21. Refer to Ground Inspection in

GI-41, "Circuit Inspection"

.

Is the inspection result normal?

YES

>> GO TO 2.

NO

>> Repair or replace ground connection.

2.

CHECK HO2S2 POWER SUPPLY CIRCUIT

1.

Disconnect HO2S2 harness connector.

2.

Turn ignition switch ON.

3.

Check the voltage between HO2S2 harness connector and ground.

Is the inspection result normal?

YES

>> GO TO 4.

NO

>> GO TO 3.

3.

DETECT MALFUNCTIONING PART

Check the following.
• 10A fuse (No. 56)
• 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 the continuity between HO2S2 harness connector and ECM harness connector.

4.

Also check harness for short to ground and short to power.

Is the inspection result normal?

YES

>> GO TO 6.

NO

>> GO TO 5.

5.

DETECT MALFUNCTIONING PART

Check the following.
• Harness connectors F121, E7
• Harness for open or short between heated oxygen sensor 2 and ECM

>> Repair open circuit or short to ground or short to power in harness or connectors.

6.

CHECK HO2S2 HEATER

Refer to

EC-173, "Component Inspection"

.

Is the inspection result normal?

YES

>> GO TO 8.

NO

>> GO TO 7.

HO2S2

Ground

Voltage

Connector

Terminal

E58

2

Ground

Battery voltage

HO2S2

ECM

Continuity

Connector

Terminal

Connector

Terminal

E58

3

F7

5

Existed

P0141 HO2S2 HEATER

EC-173

< COMPONENT DIAGNOSIS >

[HR16DE (WITH EURO-OBD)]

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7.

REPLACE HEATED OXYGEN SENSOR 2

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 and approved anti-seize lubricant.

>> INSPECTION END

8.

CHECK INTERMITTENT INCIDENT

Refer to

GI-39, "Intermittent Incident"

.

>> INSPECTION END

Component Inspection

INFOID:0000000001056189

1.

CHECK HEATED OXYGEN SENSOR 2 HEATER

1.

Turn ignition switch OFF.

2.

Disconnect heated oxygen sensor 2 harness connector.

3.

Check resistance between HO2S2 terminals as follows.

Is the inspection result normal?

YES

>> INSPECTION END

NO

>> GO TO 2.

2.

REPLACE HEATED OXYGEN SENSOR 2

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 and approved anti-seize lubricant.

>> INSPECTION END

Terminals

Resistance [at 25

°

C (77

°

F)]

2 and 3

3.3 - 4.4

Ω

1 and 2, 3, 4

∞

Ω

(Continuity should not exist)

4 and 1, 2, 3

EC-174

< COMPONENT DIAGNOSIS >

[HR16DE (WITH EURO-OBD)]

P0171 FUEL INJECTION SYSTEM FUNCTION

P0171 FUEL INJECTION SYSTEM FUNCTION

DTC Logic

INFOID:0000000001056275

DTC DETECTION LOGIC

With the Air/Fuel Mixture Ratio Self-Learning Control, the actual mixture ratio can be brought closely to the
theoretical mixture ratio based on the mixture ratio feedback signal from the heated oxygen sensors 1. The
ECM calculates the necessary compensation to correct the offset between the actual and the theoretical
ratios.
In case the amount of the compensation value is extremely large (The actual mixture ratio is too lean.), the
ECM judges the condition as the fuel injection system malfunction and lights up the MI (2 trip detection logic).

DTC CONFIRMATION PROCEDURE

1.

PRECONDITIONING

If DTC Confirmation Procedure has been previously conducted, always turn ignition switch OFF and wait at
least 10 seconds before conducting the next test.

>> GO TO 2.

2.

PERFORM DTC CONFIRMATION PROCEDURE-I

1.

Clear the mixture ratio self-learning value. Refer to

EC-33, "MIXTURE RATIO SELF-LEARNING VALUE

CLEAR : Special Repair Requirement"

.

2.

Start engine.

Is it difficult to start engine?

YES

>> GO TO 3.

NO

>> GO TO 4.

3.

RESTART ENGINE

If it is difficult to start engine, the fuel injection system has a malfunction, too.
Crank engine while depressing accelerator pedal.

Does engine start?

YES

>> Go to

EC-175, "Diagnosis Procedure"

.

NO

>> Check exhaust and intake air leak visually.

4.

PERFORM DTC CONFIRMATION PROCEDURE-II

1.

Start engine and let it idle for at least 10 minutes.

2.

Check 1st trip DTC.

Is 1st trip DTC detected?

YES

>> Go to

EC-175, "Diagnosis Procedure"

.

NO

>> GO TO 5.

5.

PERFORM DTC CONFIRMATION PROCEDURE-III

1.

Turn ignition switch OFF and wait at least 10 seconds.

Sensor

Input signal to ECM

ECM function

Actuator

Heated oxygen sensor 1

Density of oxygen in exhaust gas
(Mixture ratio feedback signal)

Fuel injection control

Fuel injector

DTC No.

Trouble diagnosis name

DTC detecting condition

Possible cause

P0171

Fuel injection system too
lean

• Fuel injection system does not operate properly.
• The amount of mixture ratio compensation is too

large. (The mixture ratio is too lean.)

• Intake air leaks
• Heated oxygen sensor 1
• Fuel injector
• Exhaust gas leaks
• Incorrect fuel pressure
• Lack of fuel
• Mass air flow sensor
• Incorrect PCV hose connection