Nissan Maxima. Manual - part 489

EC-440

< DTC/CIRCUIT DIAGNOSIS >

[VQ35DE]

P1720 VSS

P1720 VSS

Description

INFOID:0000000010095139

ECM receives two vehicle speed signals via the CAN communication line. One is sent from “ABS actuator and

electric unit (control unit)” via the combination meter, and the other is from TCM (Transmission control mod-

ule). ECM uses these signals for engine control.

DTC Logic

INFOID:0000000010095140

DTC DETECTION LOGIC

NOTE:

• If DTC P1720 is displayed with DTC UXXXX first perform the trouble diagnosis for DTC UXXXX. Refer

to 

EC-161, "DTC Logic"

.

• If DTC P1720 is displayed with DTC P0607, first perform the trouble diagnosis for DTC P0607. Refer

to 

EC-393, "DTC Logic"

.

DTC CONFIRMATION PROCEDURE

1.

PRECONDITIONING

If DTC Confirmation Procedure has been previously conducted, always perform the following before conduct-

ing the next test.

1. Turn ignition switch OFF and wait at least 10 seconds.

2. Turn ignition switch ON.

3. Turn ignition switch OFF and wait at least 10 seconds.

>> GO TO 2.

2.

PERFORM DTC CONFIRMATION PROCEDURE

1. Start engine.

2. Drive vehicle at a speed of 20 km/h (12 MPH) or more for at least 5 seconds without depressing the brake

pedal.

3. Check 1st trip DTC.
Is 1st trip DTC detected?

YES

>> Go to 

EC-440, "Diagnosis Procedure"

.

NO

>> INSPECTION END

Diagnosis Procedure

INFOID:0000000010095141

1.

CHECK DTC WITH TCM

Check DTC with TCM. Refer to 

TM-36, "Diagnosis Description"

.

Is the inspection result normal?

YES

>> GO TO 2.

NO

>> Perform trouble shooting relevant to DTC indicated.

2.

CHECK DTC WITH “ABS ACTUATOR AND ELECTRIC UNIT (CONTROL UNIT)”

Refer to 

BRC-21, "CONSULT Function (ABS)"

.

DTC No.

Trouble diagnosis name

DTC detecting condition

Possible cause

P1720

Vehicle speed sensor
(TCM output)

The difference between two vehicle speed 
signals is out of the specified range.

• Harness or connectors

(Output speed sensor circuit is open or short-
ed.)

• Harness or connectors

(Wheel sensor circuit is open or shorted.)

• TCM
• Output speed sensor
• ABS actuator and electric unit (control unit)
• Wheel sensor
• Combination meter

P1720 VSS

EC-441

< DTC/CIRCUIT DIAGNOSIS >

[VQ35DE]

C

D

E

F

G

H

I

J

K

L

M

A

EC

N

P

O

Is the inspection result normal?

YES

>> GO TO 3.

NO

>> perform trouble shooting relevant to DTC indicated.

3.

CHECK COMBINATION METER FUNCTION

Refer to 

MWI-29, "CONSULT Function (METER/M&A)"

.

>> INSPECTION END

EC-442

< DTC/CIRCUIT DIAGNOSIS >

[VQ35DE]

P1800 VIAS CONTROL SOLENOID VALVE 1

P1800 VIAS CONTROL SOLENOID VALVE 1

Description

INFOID:0000000010095142

The VIAS control solenoid valve 1 cuts the intake manifold vacuum signal for power valve 1 control. It

responds to ON/OFF signals from the ECM. When the solenoid is OFF, the vacuum signal from the intake

manifold is cut. When the ECM sends an ON signal the coil pulls the plunger downward and sends the vac-

uum signal to the power valve actuator 1.

DTC Logic

INFOID:0000000010095143

DTC DETECTION LOGIC

DTC CONFIRMATION PROCEDURE

1.

CONDITIONING

If DTC Confirmation Procedure has been previously conducted, always perform the following before conduct-

ing the next test.

1. Turn ignition switch OFF and wait at least 10 seconds.

2. Turn ignition switch ON.

3. Turn ignition switch OFF and wait at least 10 seconds.

TESTING CONDITION:

Before performing the following procedure, confirm battery voltage is more than 11 V at idle.

>> GO TO 2.

2.

PERFORM DTC CONFIRMATION PROCEDURE

1. Start engine and let it idle for at least 5 seconds.

2. Check 1st trip DTC.
Is 1st trip DTC detected?

YES

>> Go to 

EC-442, "Diagnosis Procedure"

.

NO

>> INSPECTION END

Diagnosis Procedure

INFOID:0000000010095144

Regarding Wiring Diagram information, refer to 

EC-554, "Wiring Diagram"

.

1.

CHECK VIAS CONTROL SOLENOID VALVE 1 POWER SUPPLY CIRCUIT

1. Turn ignition switch OFF.

2. Disconnect VIAS control solenoid valve 1 harness connector.

3. Turn ignition switch ON.

4. Check the voltage between VIAS control solenoid valve 1 har-

ness connector and ground.

Is the inspection result normal?

YES

>> GO TO 2.

NO

>> Repair open circuit, short to ground or short to power in

harness or connectors.

DTC No.

Trouble diagnosis name

DTC detecting condition

Possible cause

P1800

VIAS control solenoid valve 1 
circuit

An excessively low or high voltage signal 
is sent to ECM via the VIAS control sole-
noid valve 1.

• Harness or connectors

(The solenoid valve 1 circuit is open or 
shorted.)

• VIAS control solenoid valve 1

VIAS control solenoid valve 1

Ground

Voltage

Connector

Terminal

F63

1

Ground

Battery voltage

PBIB0080E

P1800 VIAS CONTROL SOLENOID VALVE 1

EC-443

< DTC/CIRCUIT DIAGNOSIS >

[VQ35DE]

C

D

E

F

G

H

I

J

K

L

M

A

EC

N

P

O

2.

CHECK VIAS CONTROL SOLENOID VALVE 1 OUTPUT SIGNAL CIRCUIT FOR OPEN AND SHORT

1. Turn ignition switch OFF.

2. Disconnect ECM harness connector.

3. Check the continuity between VIAS control solenoid valve 1 harness connector and ECM harness con-

nector.

4. Also check harness for short to ground and short to power.
Is the inspection result normal?

YES

>> GO TO 3.

NO

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

3.

CHECK VIAS CONTROL SOLENOID VALVE 1

Refer to 

EC-443, "Component Inspection"

.

Is the inspection result normal?

YES

>> GO TO 4.

NO

>> Replace VIAS control solenoid valve 1. Refer to 

EM-25, "Removal and Installation"

.

4.

CHECK INTERMITTENT INCIDENT

Refer to 

GI-41, "Intermittent Incident"

.

>> INSPECTION END

Component Inspection

INFOID:0000000010095145

1.

CHECK VIAS CONTROL SOLENOID VALVE 1

With CONSULT

1. Turn ignition switch OFF.

2. Reconnect all harness connectors disconnected.

3. Disconnect vacuum hoses connected to VIAS control solenoid valve 1.

4. Turn ignition switch ON.

5. Select “VIAS S/V-1” in “ACTIVE TEST” mode with CONSULT.

6. Check air passage continuity and operation delay time under the

following conditions.

Without CONSULT

1. Turn ignition switch OFF.

2. Disconnect VIAS control solenoid valve 1 harness connector.

3. Disconnect vacuum hoses connected to VIAS volume control solenoid valve 1.

VIAS control solenoid valve 1

ECM

Continuity

Connector

Terminal

Connector

Terminal

F63

2

F14

27

Existed

Condition

(VIAS S/V 1)

Air passage continuity 

between (A) and (B)

Air passage continuity 

between (A) and (C)

ON

Existed

Not existed

OFF

Not existed

Existed

JMBIA0180ZZ