Nissan Titan A60. Manual - part 432

EC-394

< DTC/CIRCUIT DIAGNOSIS >

[VK56DE]

P1572 ASCD BRAKE SWITCH

OK or NG

OK

>> GO TO 11.

NG

>> GO TO 7.

3.

CHECK ASCD BRAKE SWITCH POWER SUPPLY CIRCUIT

1. Turn ignition switch OFF.

2. Disconnect ASCD brake switch harness connector.

3. Turn ignition switch ON.

4. Check voltage between ASCD brake switch terminal 1 and

ground with CONSULT-III or tester.

OK or NG

OK

>> GO TO 5.

NG

>> GO TO 4.

4.

DETECT MALFUNCTIONING PART

Check the following.

• Harness connectors M31, E152

• Fuse block (J/B) connector M4

• 10A fuse

• Harness for open or short between ASCD brake switch and fuse

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

5.

CHECK ASCD BRAKE SWITCH INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT

1. Turn ignition switch OFF.

2. Disconnect ECM harness connector.

3. Check harness continuity between ECM terminal 108 and ASCD brake switch terminal 2.

Refer to Wiring Diagram.

4. Also check harness for short to ground and short to power.
OK or NG

OK

>> GO TO 6.

NG

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

CONDITION

VOLTAGE

Brake pedal: Fully released

Approximately 0V

Brake pedal: Slightly depressed

Battery voltage

PBIB1537E

BBIA0373E

Voltage: Battery voltage

PBIB0857E

Continuity should exist.

P1572 ASCD BRAKE SWITCH

EC-395

< DTC/CIRCUIT DIAGNOSIS >

[VK56DE]

C

D

E

F

G

H

I

J

K

L

M

A

EC

N

P

O

6.

CHECK ASCD BRAKE SWITCH

Refer to 

EC-396, "Component Inspection"

.

OK or NG

OK

>> GO TO 11.

NG

>> Replace ASCD brake switch.

7.

CHECK STOP LAMP SWITCH POWER SUPPLY CIRCUIT

1. Turn ignition switch OFF.

2. Disconnect stop lamp switch harness connector.

3. Check voltage between stop lamp switch terminal 1 and ground

with CONSULT-III or tester.

OK or NG

OK

>> GO TO 9.

NG

>> GO TO 8.

8.

DETECT MALFUNCTIONING PART

Check the following.

• Harness connectors M31, E152

• Fuse block (J/B) connector M60

• 10A fuse

• Harness for open or short between stop lamp switch and battery

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

9.

CHECK STOP LAMP SWITCH INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT

1. Disconnect ECM harness connector.

2. Check harness continuity between ECM terminal 101 and stop lamp switch terminal 2.

Refer to Wiring Diagram.

3. Also check harness for short to ground and short to power.
OK or NG

OK

>> GO TO 10.

NG

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

10.

CHECK STOP LAMP SWITCH

Refer to 

EC-396, "Component Inspection"

.

OK or NG

OK

>> GO TO 11.

BBIA0373E

Voltage: Battery voltage

WBIA0545E

Continuity should exist.

EC-396

< DTC/CIRCUIT DIAGNOSIS >

[VK56DE]

P1572 ASCD BRAKE SWITCH

NG

>> Replace stop lamp switch.

11.

CHECK INTERMITTENT INCIDENT

Refer to 

GI-36, "How to Check Terminal"

 and 

GI-39, "Intermittent Incident"

.

>> INSPECTION END

Component Inspection

INFOID:0000000006158865

ASCD BRAKE SWITCH

1. Turn ignition switch OFF.
2. Disconnect ASCD brake switch harness connector.
3. Check harness continuity between ASCD brake switch terminals

1 and 2 under the following conditions.

If NG, adjust ASCD brake switch installation, refer to 

BR-13,

"Inspection and Adjustment - Standard Pedal"

, and perform step

3 again.

STOP LAMP SWITCH

1. Turn ignition switch OFF.
2. Disconnect stop lamp switch harness connector.
3. Check harness continuity between stop lamp switch terminals 1

and 2 under the following conditions.

If NG, adjust stop lamp switch installation, refer to 

BR-13,

"Inspection and Adjustment - Standard Pedal"

, and perform step

3 again.

Condition

Continuity

Brake pedal: Fully released

Should exist.

Brake pedal: Slightly depressed

Should not exist.

SEC023D

Condition

Continuity

Brake pedal: Fully released

Should not exist.

Brake pedal: Slightly depressed

Should exist.

WBIA0546E

P1574 ASCD VEHICLE SPEED SENSOR

EC-397

< DTC/CIRCUIT DIAGNOSIS >

[VK56DE]

C

D

E

F

G

H

I

J

K

L

M

A

EC

N

P

O

P1574 ASCD VEHICLE SPEED SENSOR

Component Description

INFOID:0000000006158866

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

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

trol. Refer to 

EC-28

 for ASCD functions.

On Board Diagnosis Logic

INFOID:0000000006158867

• This self-diagnosis has the one trip detection logic.

• The MIL will not light up for this self-diagnosis.

NOTE:

• If DTC P1574 is displayed with DTC U0101, U1001, first perform the trouble diagnosis for DTC U0101,

U1001. Refer to 

EC-140

.

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

to 

EC-331

.

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

to 

EC-342

.

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

to 

EC-344

.

DTC Confirmation Procedure

INFOID:0000000006158868

CAUTION:

Always drive vehicle at a safe speed.

NOTE:

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

ing the next step. 
1. Turn ignition swich OFF and wait at least 10 seconds.
2. Turn ignition swich ON.
3. Turn ignition swich OFF and wait at least 10 seconds.
TESTING CONDITION:

Step 3 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.

1. Start engine (VDC switch OFF).

2. Drive the vehicle at more than 40 km/h (25 MPH).

3. Check DTC.

4. If DTC is detected, go to 

EC-397, "Diagnosis Procedure"

.

Diagnosis Procedure

INFOID:0000000006158869

1.

CHECK DTC WITH TCM

Check DTC with TCM. Refer to 

TM-34, "OBD-II Diagnostic Trouble Code (DTC)"

.

OK or NG

OK

>> GO TO 2.

NG

>> Perform trouble shooting relevant to DTC indicated.

2.

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

DTC No.

Trouble Diagnosis 

Name

DTC Detecting Condition

Possible Cause

P1574
1574

ASCD vehicle speed 
sensor

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

• Harness or connectors

(The CAN communication line is open or 
shorted.)

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