Nissan Versa Sedan. Manual - part 346

P1572 ASCD BRAKE SWITCH

EC-383

< DTC/CIRCUIT DIAGNOSIS >

[HR16DE]

C

D

E

F

G

H

I

J

K

L

M

A

EC

N

P

O

Is the inspection result normal?

YES

>> Check intermittent incident. Refer to 

GI-45, "Intermittent Incident"

.

NO

>> GO TO 6.

3.

CHECK BRAKE PEDAL POSITION SWITCH POWER SUPPLY

1. Turn ignition switch OFF.

2. Disconnect brake pedal position switch harness connector.

3. Turn ignition switch ON.

4. Check the voltage between brake pedal position switch harness connector and ground.

Is the inspection result normal?

YES

>> GO TO 4.

NO

>> Perform the trouble diagnosis for power supply circuit.

4.

CHECK BRAKE PEDAL POSITION SWITCH INPUT SIGNAL CIRCUIT

1. Turn ignition switch OFF.

2. Disconnect ECM harness connector.

3. Check the continuity between brake pedal position switch harness connector and ECM harness connec-

tor.

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

YES

>> GO TO 5.

NO

>> Repair or replace error-detected parts.

5.

CHECK BRAKE PEDAL POSITION SWITCH

Check the brake pedal position switch. Refer to 

EC-384, "Component Inspection (Brake Pedal Position

Switch)"

Is the inspection result normal?

YES

>> Check intermittent incident. Refer to 

GI-45, "Intermittent Incident"

.

NO

>> Replace brake pedal position switch. Refer to 

BR-19, "Exploded View"

.

6.

CHECK STOP LAMP SWITCH POWER SUPPLY CIRCUIT

1. Turn ignition switch OFF.

2. Disconnect stop lamp switch harness connector.

3. Check the voltage between stop lamp switch harness connector and ground.

Is the inspection result normal?

ECM

Condition

Voltage

(Approx.)

Connector

+

–

Terminal

E16

99

108

Brake pedal

Slightly depressed

Battery voltage

Fully released

0 V

Brake pedal position switch

Ground

Voltage

Connector

Terminal

E36

1

Ground

Battery voltage

Brake pedal position switch

ECM

Continuity

Connector

Terminal

Connector

Terminal

E36

2

E16

100

Existed

Stop lamp switch

Ground

Voltage

Connector

Terminal

E13

1

Ground

Battery voltage

EC-384

< DTC/CIRCUIT DIAGNOSIS >

[HR16DE]

P1572 ASCD BRAKE SWITCH

YES

>> GO TO 7.

NO

>> Perform the trouble diagnosis for power supply circuit.

7.

CHECK STOP LAMP SWITCH INPUT SIGNAL CIRCUIT

1. Disconnect ECM harness connector.

2. Check the continuity between stop lamp switch harness connector and ECM harness connector.

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

YES

>> GO TO 8.

NO

>> Repair or replace error-detected parts.

8.

CHECK STOP LAMP SWITCH

Check the stop lamp switch. Refer to 

EC-384, "Component Inspection (Stop Lamp Switch)"

.

Is the inspection result normal?

YES

>> Check intermittent incident. Refer to 

GI-45, "Intermittent Incident"

.

NO

>> Replace stop lamp switch. Refer to 

BR-19, "Exploded View"

.

Component Inspection (Brake Pedal Position Switch)

INFOID:0000000009267259

1.

CHECK BRAKE PEDAL POSITION SWITCH-I

1. Turn ignition switch OFF.

2. Disconnect brake pedal position switch harness connector.

3. Check the continuity between brake pedal position switch terminals as per the following conditions.

Is the inspection result normal?

YES

>> INSPECTION END

NO

>> GO TO 2.

2.

CHECK BRAKE PEDAL POSITION SWITCH-II

1. Adjust brake pedal position switch installation. Refer to 

BR-8, "Inspection and Adjustment"

.

2. Check the continuity between brake pedal position switch terminals as per the following conditions.

Is the inspection result normal?

YES

>> INSPECTION END

NO

>> Replace brake pedal position switch. Refer to 

BR-19, "Exploded View"

.

Component Inspection (Stop Lamp Switch)

INFOID:0000000009267260

1.

CHECK STOP LAMP SWITCH-I

1. Turn ignition switch OFF.

2. Disconnect stop lamp switch harness connector.

Stop lamp switch

ECM

Continuity

Connector

Terminal

Connector

Terminal

E13

2

E16

99

Existed

Brake pedal position switch

Condition

Continuity

Terminals

1

 2

Brake pedal

Fully released

Existed

Slightly depressed

Not existed

Brake pedal position switch

Condition

Continuity

Terminals

1

 2

Brake pedal

Fully released

Existed

Slightly depressed

Not existed

P1572 ASCD BRAKE SWITCH

EC-385

< DTC/CIRCUIT DIAGNOSIS >

[HR16DE]

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3. Check the continuity between stop lamp switch terminals as per the following conditions.

Is the inspection result normal?

YES

>> INSPECTION END

NO

>> GO TO 2.

2.

CHECK STOP LAMP SWITCH-II

1. Adjust stop lamp switch installation. Refer to 

BR-8, "Inspection and Adjustment"

.

2. Check the continuity between stop lamp switch terminals as per the following conditions.

Is the inspection result normal?

YES

>> INSPECTION END

NO

>> Replace stop lamp switch. Refer to 

BR-19, "Exploded View"

.

Stop lamp switch

Condition

Continuity

Terminals

1

 2

Brake pedal

Fully released

Not existed

Slightly depressed

Existed

Stop lamp switch

Condition

Continuity

Terminals

1

 2

Brake pedal

Fully released

Not existed

Slightly depressed

Existed

EC-386

< DTC/CIRCUIT DIAGNOSIS >

[HR16DE]

P1574 ASCD VEHICLE SPEED SENSOR

P1574 ASCD VEHICLE SPEED SENSOR

Description

INFOID:0000000009267261

The ECM receives two vehicle speed sensor signals via CAN communication line. One is sent from combina-

tion meter, and the other is from TCM (Transmission control module). The ECM uses these signals for ASCD

control. Refer to 

EC-46, "AUTOMATIC SPEED CONTROL DEVICE (ASCD) : System Description"

 for ASCD

functions.

DTC Logic

INFOID:0000000009267262

DTC DETECTION LOGIC

NOTE:

• If DTC P1574 is displayed with DTC U1001, first perform the trouble diagnosis for DTC U1001. Refer

to 

EC-159, "DTC Logic"

.

• If DTC P1574 is displayed with DTC P0500, first perform the trouble diagnosis for DTC P0500. Refer

to 

EC-327, "DTC Logic"

• If DTC P1574 is displayed with DTC P0605, first perform the trouble diagnosis for DTC P0605. Refer

to 

EC-341, "DTC Logic"

• If DTC P1574 is displayed with DTC P0607, first perform the trouble diagnosis for DTC P0607. Refer

to 

EC-343, "DTC Logic"

.

DTC CONFIRMATION PROCEDURE

1.

PRECONDITIONING

If DTC Confirmation Procedure has been previously conducted, always perform the following procedure

before conducting 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 the vehicle at more than 40 km/h (25 MPH).

CAUTION:

Always drive vehicle at a safe speed.

NOTE:

This procedure may be conducted with the drive wheels lifted in the shop or by driving the vehicle.

If a road test is expected to be easier, it is unnecessary to lift the vehicle.

3. Check DTC.
Is DTC detected?

YES

>> Proceed to 

EC-386, "Diagnosis Procedure"

.

NO

>> INSPECTION END

Diagnosis Procedure

INFOID:0000000009267263

1.

CHECK DTC WITH TCM

Check DTC with TCM. Refer to 

TM-93, "CONSULT Function"

 (A/T models) or 

TM-293, "CONSULT Function"

(CVT models).

DTC No.

Trouble diagnosis name

(Trouble diagnosis content)

DTC detecting condition

Possible cause

P1574

ASCD VHL SPD SEN
(ASCD vehicle speed sensor)

ECM detects a difference between 
two vehicle speed signals is out of 
the specified range.

• Harness or connectors

(CAN communication line is open or shorted.)

• ABS actuator and electric unit (control unit)
• TCM
• ECM