Nissan Frontier D40. Manual - part 528

P1572 ASCD BRAKE SWITCH

EC-803

< COMPONENT DIAGNOSIS >

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2.

Disconnect stop lamp switch harness connector.

3.

Check voltage between stop lamp switch terminal 2 and ground
with CONSULT-III or tester.

OK or NG

OK

>> GO TO 12.

NG

>> GO TO 11.

11.

DETECT MALFUNCTIONING PART

Check the following.
• Fuse block (J/B) connector F160
• 10 A fuse (No.20)
• 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.

12.

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 13.

NG

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

13.

CHECK STOP LAMP SWITCH

Refer to 

EC-803, "Component Inspection"

.

OK or NG

OK

>> GO TO 14.

NG

>> Replace stop lamp switch.

14.

CHECK INTERMITTENT INCIDENT

Refer to 

GI-46, "Intermittent Incident"

.

>> INSPECTION END

Component Inspection

INFOID:0000000005273806

ASCD BRAKE SWITCH

BBIA0560E

Voltage: Battery voltage

MBIB1407E

Continuity should exist.

EC-804

< COMPONENT DIAGNOSIS >

[VQ40DE]

P1572 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-19,

"Inspection and Adjustment"

, and perform step 3 again.

ASCD CLUTCH SWITCH

1.

Turn ignition switch OFF.

2.

Disconnect ASCD clutch switch harness connector.

3.

Check harness continuity between ASCD clutch switch termi-
nals 1 and 2 under the following conditions.

If NG, adjust ASCD clutch switch installation, refer to 

CL-8, "On-

Vehicle Inspection and Adjustment"

, 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-19,

"Inspection and Adjustment"

, and perform step 3 again.

Condition

Continuity

When brake pedal: Fully released.

Should exist.

When brake pedal: Slightly depressed.

Should not exist.

SEC023D

Condition

Continuity

Clutch pedal: Fully released

Should exist

Clutch pedal: Slightly depressed

Should not exist

SEC024D

Condition

Continuity

When brake pedal: Fully released.

Should not exist.

When brake pedal: Slightly depressed.

Should exist.

PBIB1185E

P1574 ASCD VEHICLE SPEED SENSOR

EC-805

< COMPONENT DIAGNOSIS >

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P1574 ASCD VEHICLE SPEED SENSOR

Component Description

INFOID:0000000005273807

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-489, "System Description"

 for ASCD functions.

On Board Diagnosis Logic

INFOID:0000000005273808

This self-diagnosis has the one trip detection logic.
The MIL will not illuminate for this diagnosis.
NOTE:
• If DTC P1574 is displayed with DTC UXXXX, first perform the trouble diagnosis for DTC UXXXX.
• If DTC P1574 is displayed with DTC P0607, first perform the trouble diagnosis for DTC P0607. Refer

to 

EC-757, "On Board Diagnosis Logic"

.

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

to 

EC-742, "Description"

.

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

to 

EC-755, "Component Description"

.

DTC Confirmation Procedure

INFOID:0000000005273809

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 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:
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.

2.

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

3.

Check DTC.

4.

If DTC is detected, go to 

EC-805, "Diagnosis Procedure"

.

Diagnosis Procedure

INFOID:0000000005273810

1.

CHECK DTC WITH TCM

Check DTC with TCM. Refer to 

TM-149, "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)”

Refer to 

BRC-10, "Work Flow"

 or 

BRC-185, "Work Flow"

.

DTC No.

Trouble Diagnosis 

Name

DTC Detecting Condition

Possible Cause

P1574
1574

ASCD vehicle speed 
sensor

The difference between the 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 (A/T models)
• ECM

EC-806

< COMPONENT DIAGNOSIS >

[VQ40DE]

P1574 ASCD VEHICLE SPEED SENSOR

OK or NG

OK

>> GO TO 3.

NG

>> Repair or replace.

3.

CHECK COMBINATION METER FUNCTION

Refer to 

MWI-3, "Work Flow"

.

>> INSPECTION END