Infiniti G37 Coupe. Manual — part 1241

VEHICLE SPEED SIGNAL CIRCUIT

STC-15

< COMPONENT DIAGNOSIS >

[WITHOUT 4WAS]

C

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STC

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VEHICLE SPEED SIGNAL CIRCUIT

Description

INFOID:0000000001666278

• Unified meter and A/C amp. sends vehicle speed signal to power steering control unit.

Diagnosis Procedure

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1.

PERFORM UNIFIED METER AND A/C AMP. SELF-DIAGNOSIS

With CONSULT-III

Perform unified meter and A/C amp. self-diagnosis.

Is any error system detected?

YES

>> Check the error system.

NO

>> GO TO 2.

2.

CHECK HARNESS BETWEEN UNIFIED METER AND A/C AMP. AND POWER STEERING CONTROL

UNIT

1.

Turn the ignition switch OFF.

2.

Disconnect unified meter and A/C amp. harness connector.

3.

Disconnect power steering control unit harness connector.

4.

Check continuity between unified meter and A/C amp. harness connector and power steering control unit
harness connector.

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

Is the inspection result normal?

YES

>> GO TO 3.

NO

>> Repair or replace damaged parts.

3.

CHECK VEHICLE SPEED SIGNAL (1)

1.

Turn the ignition switch OFF.

2.

Connect unified meter and A/C amp. harness connector.

3.

Check unified meter and A/C amp. input/output standard values. Refer to

MWI-69, "Reference Value"

.

Is the inspection result normal?

YES

>> GO TO 4.

NO

>> Replace unified meter and A/C amp. Refer to

MWI-160, "Exploded View"

.

4.

CHECK VEHICLE SPEED SIGNAL (2)

1.

Turn the ignition switch OFF.

2.

Connect power steering control unit harness connector.

3.

Check signal between power steering control unit harness connector and ground with oscilloscope.

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

Unified meter and A/C amp.

Power steering control unit

Continuity

Connector

Terminal

Connector

Terminal

M66

8

M108

8

Existed

Power steering control unit

Value (Approx.)

Connector

Terminal

Condition

M108

8 – Ground

Vehicle speed:
40 km/h (25 MPH)

CAUTION:

Check air pressure of tire under
standard condition.

SEIA0775E

STC-16

< COMPONENT DIAGNOSIS >

[WITHOUT 4WAS]

VEHICLE SPEED SIGNAL CIRCUIT

Is the inspection result normal?

YES

>> GO TO 5.

NO

>> Replace power steering control unit. Refer to

STC-24, "Exploded View"

.

5.

CHECK TERMINALS AND HARNESS CONNECTORS

• Check power steering control unit pin terminals for damage or loose connection with harness connector.
• Check unified meter and A/C amp. pin terminals for damage or loose connection with harness connector.

Is the inspection result normal?

YES

>> INSPECTION END

NO

>> Repair or replace damaged parts.

POWER STEERING CONTROL UNIT

STC-17

< ECU DIAGNOSIS >

[WITHOUT 4WAS]

C

D

E

F

H

I

J

K

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M

A

B

STC

N

O

P

ECU DIAGNOSIS

POWER STEERING CONTROL UNIT

Reference Value

INFOID:0000000001666280

TERMINAL LAYOUT

PHYSICAL VALUES

CAUTION:

JSGIA0023ZZ

Terminal No.

Wire

color

Description

Condition

Value (Approx.)

+

-

Signal name

Input/

Output

1

Ground

LG

Power steering so-
lenoid valve voltage

Output

Vehicle speed: 0 km/h (0 MPH)
(Engine is running)

4.4 – 6.6 V

Vehicle speed: 100 km/h (62 MPH)

2.4 – 3.6 V

3

Ground

G

Ignition switch pow-
er supply

Input

Ignition switch: ON

Battery voltage

Ignition switch: OFF

0 V

5

Ground

B

Power steering so-
lenoid valve ground

—

Always

0 V

6

Ground

B

Ground

—

Always

0 V

8

Ground

L

Vehicle speed sig-
nal

Input

Vehicle speed: 40 km/h (25 MPH)

CAUTION:

Check air pressure of tire under
standard condition.

10

Ground

R

Engine speed signal

Input

Engine speed: At idle
(Warm-up condition)

Engine speed: Approx. 2,000 rpm
(Warm-up condition)

SEIA0775E

PBIA3654J

PBIA3655J

STC-18

< ECU DIAGNOSIS >

[WITHOUT 4WAS]

POWER STEERING CONTROL UNIT

When using circuit tester or oscilloscope to measure voltage for inspection, be sure not to forcibly extend any connector ter-
minals.

Wiring Diagram - ELECTRONICALLY CONTROLLED POWER STEERING SYSTEM -

INFOID:0000000001666281

Click here to view the eWD.

JCGWA0046GB