Nissan Altima L32. Instruction — part 1398

ENGINE SPEED SIGNAL CIRCUIT

STC-11

< COMPONENT DIAGNOSIS >

C

D

E

F

H

I

J

K

L

M

A

B

STC

N

O

P

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

Is the inspection result normal?

YES

>> GO TO 4.

NO

>> Replace ECM. Refer to

EC-34, "Component Parts Location"

(QR25DE for California),

EC-570,

"Component Parts Location"

(QR25DE except for California),

EC-1058,

"Component Parts Location"

(VQ35DE).

4.

CHECK ENGINE SPEED SIGNAL (POWER STEERING CONTROL UNIT SIDE)

1. Turn the ignition switch OFF.

2. Connect power steering control unit harness connector.

3. Check signal between power steering control unit harness con-

nector M59 terminal 10 and ground with oscilloscope.

ECM

Value (Approx.)

Connector

Terminal

Condition

E10

94 - Ground

Engine speed:
At idle
(Warm-up con-
dition)

QR25DE:

VQ35DE:

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

QR25DE:

VQ35DE:

JSGIA0144ZZ

JSGIA0143ZZ

JSGIA0145ZZ

PBIA3655J

AWGIA0041ZZ

STC-12

< COMPONENT DIAGNOSIS >

ENGINE SPEED SIGNAL CIRCUIT

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

Is the inspection result normal?

YES

>> GO TO 5.

NO

>> Replace power steering control unit.

5.

CHECK TERMINALS AND HARNESS CONNECTORS

• Check power steering control unit pin terminals for damage or loose connection with harness connector.

• Check ECM 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

Value (Approx.)

Connector

Terminal

Condition

M59

10 - Ground

Engine speed:
At idle
(Warm-up con-
dition)

QR25DE:

VQ35DE:

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

QR25DE:

VQ35DE:

JSGIA0144ZZ

JSGIA0143ZZ

JSGIA0145ZZ

PBIA3655J

VEHICLE SPEED SIGNAL CIRCUIT

STC-13

< COMPONENT DIAGNOSIS >

C

D

E

F

H

I

J

K

L

M

A

B

STC

N

O

P

VEHICLE SPEED SIGNAL CIRCUIT

Description

INFOID:0000000004205834

• Combination meter sends vehicle speed signal to power steering control unit.

Diagnosis Procedure

INFOID:0000000004205835

1.

PERFORM COMBINATION METER SELF-DIAGNOSIS

Perform combination meter self-diagnosis.
Is any error system detected?

YES

>> Check the error system.

NO

>> GO TO 2.

2.

CHECK HARNESS BETWEEN COMBINATION METER AND POWER STEERING CONTROL UNIT

1. Turn the ignition switch OFF.

2. Disconnect combination meter harness connector.

3. Disconnect power steering control unit harness connector.

4. Check continuity between combination meter harness connector

M24 (A) terminal 30 and power steering control unit harness

connector M59 (B) terminal 8.

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 (COMBINATION METER SIDE)

1. Turn the ignition switch OFF.

2. Connect combination meter harness connector.

3. Check combination meter input/output standard values. Refer to

MWI-59, "Reference Value"

.

Is the inspection result normal?

YES

>> GO TO 4.

NO

>> Replace combination meter. Refer to

MWI-176, "Removal and Installation"

.

4.

CHECK VEHICLE SPEED SIGNAL (POWER STEERING CONTROL UNIT SIDE)

1. Turn the ignition switch OFF.

2. Connect power steering control unit harness connector.

3. Check signal between power steering control unit harness con-

nector M59 terminal 8 and ground with oscilloscope.

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

Combination meter

Power steering control unit

Continuity

Connector

Terminal

Connector

Terminal

M24 (A)

30

M59 (B)

8

Existed

AWGIA0042ZZ

Power steering control unit

Value (Approx.)

Connector

Terminal

Condition

M59

8 - Ground

Vehicle speed:
40 km/h (25
MPH)

CAUTION:

Check air
pressure of
tire under
standard con-
dition.

AWGIA0043ZZ

ELF1080D

STC-14

< COMPONENT DIAGNOSIS >

VEHICLE SPEED SIGNAL CIRCUIT

Is the inspection result normal?

YES

>> GO TO 5.

NO

>> Replace power steering control unit.

5.

CHECK TERMINALS AND HARNESS CONNECTORS

• Check power steering control unit pin terminals for damage or loose connection with harness connector.

• Check combination meter pin terminals for damage or loose connection with harness connector.
Is the inspection result normal?

YES

>> Inspection End

NO

>> Repair or replace damaged parts.