Infiniti Q45 (FY33). Manual - part 157

SEF123T

SEF387U

q

A

CHECK GROUND CIRCUIT.
1. Turn ignition switch “OFF”.
2. Check harness continuity between ter-

minal

q

2

and engine ground.

Continuity should exist.
If OK, check harness for short to power.

OK

E

NG

Check the following.

I

Harness connectors

F63

,

M49

I

Harness connectors

M4

,

B3

I

Joint connector-16

I

Harness for open or
short between throttle
position sensor and ECM

I

Harness for open or
short between throttle
position sensor and TCM
(Transmission Control
Module)

I

Harness for open or
short between throttle
position sensor and
throttle actuator control
(TAC) module

If NG, repair open circuit or
short to power in harness
or connectors.

CHECK INPUT SIGNAL CIRCUIT.
1. Disconnect ECM harness connector.
2. Check harness continuity between ECM

terminal

q

63

and terminal

q

1

.

Continuity should exist.
If OK, check harness for short to
ground and short to power.

OK

E

NG

Repair harness or connec-
tors.

CHECK COMPONENT
(Throttle position sensor).
Refer to “COMPONENT INSPECTION”,
EC-159.

OK

E

NG

Replace throttle position
sensor. To adjust it, per-
form “Basic Inspection”,
EC-91.

CHECK COMPONENT
(Mass air flow sensor).
Refer to “COMPONENT INSPECTION”,
EC-131.

OK

E

NG

Replace mass air flow sen-
sor.

CHECK COMPONENT
(Camshaft position sensor).
Refer to “COMPONENT INSPECTION”,
EC-280.

OK

E

NG

Replace camshaft position
sensor.

CHECK COMPONENT
(Fuel injector).
Refer to “COMPONENT INSPECTION”,
EC-520.

OK

E

NG

Replace fuel injector.

Perform “TROUBLE DIAGNOSIS FOR
INTERMITTENT INCIDENT”, EC-117.

INSPECTION END

GI

MA

EM

LC

FE

AT

PD

FA

RA

BR

ST

RS

BT

HA

EL

IDX

TROUBLE DIAGNOSIS FOR DTC P0120

Throttle Position Sensor (Cont’d)

H

H

H

H

H

H

H

H

EC-157

SEF119T

SEF053T

SEF122T

SEF123T

SEF387U

Procedure C

INSPECTION START

ADJUST THROTTLE POSITION SEN-
SOR.
Perform “Basic Inspection”, EC-91.

OK

CHECK INTAKE SYSTEM.
Check the followings for connection.

I

Air duct

I

Vacuum hoses

I

Intake air passage between air duct to
collector

If disconnected, reconnect the parts.

OK

E

NG

Reconnect the parts.

1. Turn ignition switch “OFF”.
2. Loosen and retighten engine ground

screws.

CHECK POWER SUPPLY.
1. Disconnect throttle position sensor har-

ness connector.

2. Turn ignition switch “ON”.
3. Check voltage between terminal

q

4

and

ground with CONSULT-II or tester.
Voltage: Approximately 5V

OK

E

NG

Repair harness or connec-
tors.

CHECK GROUND CIRCUIT.
1. Turn ignition switch “OFF”.
2. Check harness continuity between ter-

minal

q

2

and engine ground.

Continuity should exist.
If OK, check harness for short to power.

OK

E

NG

Check the following.

I

Harness connectors

F63

,

M49

I

Harness connectors

M4

,

B3

I

Joint connector-16

I

Harness for open or
short between throttle
position sensor and ECM

I

Harness for open or
short between throttle
position sensor and TCM
(Transmission Control
Module)

I

Harness for open or
short between throttle
position sensor and
throttle actuator control
(TAC) module

If NG, repair open circuit or
short to power in harness
or connectors.

CHECK INPUT SIGNAL CIRCUIT.
1. Disconnect ECM harness connector.
2. Check harness continuity between ECM

terminal

q

63

and terminal

q

1

.

Continuity should exist.
If OK, check harness for short to
ground and short to power.

OK

E

NG

Repair harness or connec-
tors.

q

A

(Go to next page.)

TROUBLE DIAGNOSIS FOR DTC P0120

Throttle Position Sensor (Cont’d)

H

H

H

H

H

H

H

EC-158

q

A

CHECK COMPONENT
(Throttle position sensor).
Refer to “COMPONENT INSPECTION”
below.

OK

E

NG

Replace throttle position
sensor. To adjust it, per-
form “Basic Inspection”,
EC-91.

Perform “TROUBLE DIAGNOSIS FOR
INTERMITTENT INCIDENT”, EC-117.

INSPECTION END

SEF793W

COMPONENT INSPECTION

Throttle position sensor

1.

Start engine and warm it up to normal operating temperature.

2.

Stop engine (Ignition switch “OFF”).

3.

Remove the vacuum hose connected to the throttle opener.

4.

Connect suitable vacuum hose to the vacuum pump and the
opener.

5.

Apply vacuum [more than −40.0 kPa (−300 mmHg, −11.81
inHg)] until the throttle drum becomes free from the rod of the
throttle opener.

SEF266Y

6.

Turn ignition switch “ON”.

7. Select “DATA MONITOR” mode with CONSULT-II.
8. Check voltage of “THRTL POS SEN”.
Voltage measurement must be made with throttle posi-
tion sensor installed in vehicle.

Throttle valve conditions

THRTL POS SEN

Completely closed (a)

0.15 - 0.85

Partially open

Between (a) and (b)

Completely open (b)

3.5 - 4.7

If NG, adjust closed throttle position switch. Refer to “Basic
Inspection”, EC-91.

9. If it is impossible to adjust closed throttle position switch

in “Basic Inspection”, replace throttle position sensor.

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GI

MA

EM

LC

FE

AT

PD

FA

RA

BR

ST

RS

BT

HA

EL

IDX

TROUBLE DIAGNOSIS FOR DTC P0120

Throttle Position Sensor (Cont’d)

H

H

H

EC-159

SEF795W

7. Check voltage between ECM terminal

q

63

(Throttle posi-

tion sensor signal) and ground.

Voltage measurement must be made with throttle posi-
tion sensor installed in vehicle.

Throttle valve conditions

Voltage V

Completely closed

0.15 - 0.85

Partially open

Between (a) and (b)

Completely open

3.5 - 4.7

If NG, adjust closed throttle position switch. Refer to “Basic
Inspection”, EC-91.

8. If it is impossible to adjust closed throttle position switch

in “Basic Inspection”, replace throttle position sensor.

TROUBLE DIAGNOSIS FOR DTC P0120

Throttle Position Sensor (Cont’d)

EC-160