NISSAN X-TRAIL 2005 Service Repair Manual

DTC P1572 ASCD BRAKE SWITCH
EC-387
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DTC P1572 ASCD BRAKE SWITCHPFP:25320
Component DescriptionEBS01FAB
When the brake pedal is depressed, ASCD brake switch is turned
OFF and stop lamp switch is turned ON. ECM detects the state of
the brake pedal by this input of two kinds (ON/OFF signal).
Refer to EC-529, "
AUTOMATIC SPEED CONTROL DEVICE
(ASCD)" for the ASCD function.
CONSULT-II Reference Value in Data Monitor ModeEBS01FAC
Specification data are reference values.
On Board Diagnosis LogicEBS01FAD
This self-diagnosis has the one trip detection logic.
The MI will not light up for this diagnosis.
NOTE:

If DTC P1572 is displayed with DTC P0605, first perform the trouble diagnosis for DTC P0605.
Refer to EC-283, "
DTC P0605 ECM".

This self-diagnosis has the one trip detection logic. When malfunction A is detected, DTC is not
stored in ECM memory. And in that case, 1st trip DTC and 1st trip freeze frame data are displayed.
1st trip DTC is erased when ignition switch OFF. And even when malfunction A is detected in two
consecutive trips, DTC is not stored in ECM memory.
SEC009D
MONITOR ITEM CONDITION SPECIFICATION
BRAKE SW1
(ASCD brake switch)

Ignition switch: ONClutch pedal (M/T) and brake pedal:
Fully releasedON
Clutch pedal (M/T) and/or brake pedal:
Slightly depressedOFF
BRAKE SW2
(Stop lamp switch)

Ignition switch: ONBrake pedal: Fully released OFF
Brake pedal: Slightly depressed ON
DTC No.Trouble Diagnosis
NameDTC Detecting Condition Possible Cause
P1572
1572ASCD brake switchA)When the vehicle speed is above 30km/h
(19 MPH), ON signals from the stop lamp
switch and the ASCD brake switch are sent
to ECM at the same time.

Harness or connectors
(The stop lamp switch circuit is shorted.)

Harness or connectors
(The ASCD brake switch circuit is shorted.)

Harness or connectors
(The ASCD clutch switch circuit is shorted.)
(M/T models)

Stop lamp switch

ASCD brake switch

ASCD clutch switch
(M/T models)

Incorrect stop lamp switch installation

Incorrect ASCD brake switch installation

Incorrect ASCD clutch switch installation
(M/T models)

ECM B)ASCD brake switch signal is not sent to
ECM for extremely long time while the vehi-
cle is driving

EC-388
[QR (WITH EURO-OBD)]
DTC P1572 ASCD BRAKE SWITCH

DTC Confirmation ProcedureEBS01FAE
CAUTION:
Always drive vehicle at a safe speed.
NOTE:

If DTC Confirmation Procedure has been previously conducted, always turn ignition switch OFF and wait
at least 10 seconds before conducting the next test.

Procedure for malfunction B is not described here. It takes extremely long time to complete procedure for
malfunction B. By performing procedure for malfunction A, the incident that causes malfunction B can be
detected.
TESTING CONDITION:
Steps 4 and 5 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.
WITH CONSULT-II
1. Start engine (EPS switch OFF).
2. Select “DATA MONITOR” mode with CONSULT-II.
3. Press MAIN switch and make sure that CRUISE indicator lights
up.
4. Drive the vehicle for at least 5 consecutive seconds under the
following condition.
If 1st trip DTC is detected, go to EC-390, "
Diagnostic Procedure"
.
If 1st trip DTC is not detected, go to the following step.
5. Drive the vehicle for at least 5 consecutive seconds under the following condition.
6. If 1st trip DTC is detected, go to EC-390, "
Diagnostic Procedure" .
WITH GST
Follow the procedure “WITH CONSULT-II” above.
VHCL SPEED SE More than 30 km/h (19 MPH)
Shift lever Suitable position
VHCL SPEED SE More than 30 km/h (19 MPH)
Shift lever Suitable position
Driving locationDepress the brake pedal for more than
five seconds so as not to come off from
the above-mentioned vehicle speed.
PBIB2386E

DTC P1572 ASCD BRAKE SWITCH
EC-389
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Wiring DiagramEBS01FAF
TBWA0756E

EC-390
[QR (WITH EURO-OBD)]
DTC P1572 ASCD BRAKE SWITCH

Specification data are reference values and are measured between each terminal and ground.
CAUTION:
Do not use ECM ground terminals when measuring input/output voltage. Doing so may result in dam-
age to the ECM's transistor. Use a ground other than ECM terminals, such as the ground.
Diagnostic ProcedureEBS01FAH
1. CHECK OVERALL FUNCTION-I
With CONSULT-II
1. Turn ignition switch ON.
2. Select “BRAKE SW1” in “DATA MONITOR” mode with CONSULT-II.
3. Check “BRAKE SW1” indication under the following conditions.
A/T models
M/T models
Without CONSULT-II
1. Turn ignition switch ON.
2. Check voltage between ECM terminal 108 and ground under the
following conditions.
A/T models
M/T models
OK or NG
OK >> GO TO 2.
NG >> GO TO 3.
TER-
MINAL
NO.WIRE
COLORITEM CONDITION DATA (DC Voltage)
101 P Stop lamp switch[Ignition switch: OFF]

Brake pedal: Fully releasedApproximately 0V
[Ignition switch: OFF]

Brake pedal: Slightly depressedBATTERY VOLTAGE
(11 - 14V)
108 GY/L ASCD brake switch[Ignition switch: ON]

Brake pedal and/or clutch pedal (M/T):
Slightly depressedApproximately 0V
[Ignition switch: ON]

Brake pedal and clutch pedal (M/T):
Fully releasedBATTERY VOLTAGE
(11 - 14V)
CONDITION INDICATION
Brake pedal: Slightly depressed OFF
Brake pedal: Fully released ON
CONDITION INDICATION
Clutch pedal and/or brake pedal: Slightly depressed OFF
Clutch pedal and brake pedal: Fully released ON
SEC011D
CONDITION VOLTAGE
Brake pedal: Slightly depressed Approximately 0V
Brake pedal: Fully released Battery voltage
CONDITION VOLTAGE
Clutch pedal and/or brake pedal: Slightly depressed Approximately 0V
Clutch pedal and brake pedal: Fully released Battery voltage
MBIB0061E

DTC P1572 ASCD BRAKE SWITCH
EC-391
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2. CHECK OVERALL FUNCTION-II
With CONSULT-II
1. Select “BRAKE SW2” in “DATA MONITOR” mode with CONSULT-II.
2. Check “BRAKE SW2” indication under the following conditions.
Without CONSULT-II
Check voltage between ECM terminal 101 and ground under the fol-
lowing conditions.
OK or NG
OK >> GO TO 15.
NG >> GO TO 11.
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-II or tester.
OK or NG
OK >> GO TO 9.
NG (A/T models)>>GO TO 4.
NG (M/T models)>>GO TO 5.
CONDITION INDICATION
Brake pedal: Fully released OFF
Brake pedal: Slightly depressed ON
SEC013D
CONDITION VOLTAGE
Brake pedal: Fully released Approximately 0V
Brake pedal: Slightly depressed Battery voltage
MBIB0060E
SEC009D
Voltage: Battery voltage
PBIB0857E

EC-392
[QR (WITH EURO-OBD)]
DTC P1572 ASCD BRAKE SWITCH

4. DETECT MALFUNCTIONING PART
Check the following.

Fuse block (J/B) connector M2

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 CLUTCH SWITCH POWER SUPPLY CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect ASCD clutch switch harness connector.
3. Turn ignition switch ON.
4. Check voltage between ASCD clutch switch terminal 1 and
ground with CONSULT-II or tester.
OK or NG
OK >> GO TO 7.
NG >> GO TO 6.
6. DETECT MALFUNCTIONING PART
Check the following.

Fuse block (J/B) connector M2

10A fuse

Harness for open or short between ASCD clutch switch and fuse
>> Repair open circuit or short to ground or short to power in harness or connectors.
7. CHECK ASCD BRAKE SWITCH INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch OFF.
2. Check harness continuity between ASCD clutch switch terminal 2 and ASCD brake switch terminal 1.
Refer to Wiring Diagram.
3. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 8.
NG >> Repair open circuit or short to ground or short to power in harness or connectors.
8. CHECK ASCD CLUTCH SWITCH
Refer to EC-395, "
Component Inspection"
OK or NG
OK >> GO TO 15.
NG >> Replace ASCD clutch switch.Voltage: Battery voltage
PBIB0799E
Continuity should exist.

DTC P1572 ASCD BRAKE SWITCH
EC-393
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9. 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 ASCD brake switch terminal 2 and ECM terminal 108.
Refer to Wiring Diagram.
4. 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 ASCD BRAKE SWITCH
Refer to EC-395, "
Component Inspection" .
OK or NG
OK >> GO TO 15.
NG >> Replace ASCD brake switch.
11 . 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 -II or tester.
OK or NG
OK >> GO TO 13.
NG >> GO TO 12.Continuity should exist.
PBIB0498E
Voltage: Battery voltage
PBIB2284E

EC-394
[QR (WITH EURO-OBD)]
DTC P1572 ASCD BRAKE SWITCH

12. DETECT MALFUNCTIONING PART
Check the following.

Fuse block (J/B) connector M2

15A 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.
13. 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 14.
NG >> Repair open circuit or short to ground or short to power in harness or connectors.
14. CHECK STOP LAMP SWITCH
Refer to EC-395, "
Component Inspection"
OK or NG
OK >> GO TO 15.
NG >> Replace stop lamp switch.
15. CHECK INTERMITTENT INCIDENT
Refer to EC-124, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
>>INSPECTION END Continuity should exist.

DTC P1572 ASCD BRAKE SWITCH
EC-395
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Component InspectionEBS01FAI
ASCD BRAKE SWITCH
1. Turn ignition switch OFF.
2. Disconnect ASCD brake switch harness connector.
3. Check continuity between ASCD brake switch terminals 1 and 2
under the following conditions.
If NG, adjust ASCD brake switch installation, refer to BR-6,
"BRAKE PEDAL" , and perform step 3 again.
ASCD CLUTCH SWITCH
1. Turn ignition switch OFF.
2. Disconnect ASCD clutch switch harness connector.
3. Check continuity between ASCD clutch switch terminals 1 and 2
under the following conditions.
If NG, adjust ASCD clutch switch installation, refer to CL-5,
"CLUTCH PEDAL" , and perform step 3 again.
STOP LAMP SWITCH
1. Turn ignition switch OFF.
2. Disconnect stop lamp switch harness connector.
3. Check continuity between stop lamp switch terminals 1 and 2 under the following conditions.
If NG, adjust stop lamp switch installation, refer to BR-6, "
BRAKE PEDAL" , and perform step 3 again.
Condition Continuity
Brake pedal: Fully released Should exist
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
Brake pedal: Fully released Should not exist
Brake pedal: Slightly depressed Should exist
PBIB2285E

EC-396
[QR (WITH EURO-OBD)]
DTC P1574 ASCD VEHICLE SPEED SENSOR

DTC P1574 ASCD VEHICLE SPEED SENSORPFP:31036
System DescriptionEBS01FF7
ECM receives two vehicle speed sensor signals via CAN communication line. One is sent from ESP/TCS/ABS
control unit (models with ESP) or “ABS actuator and electric unit (control unit)”(models without ESP), and the
other is from TCM (Transmission control module).
The ECM uses these signals for ASCD control. Refer to EC-529, "
AUTOMATIC SPEED CONTROL DEVICE
(ASCD)" for ASCD functions.
On Board Diagnosis LogicEBS01FAK
This self-diagnosis has the one trip detection logic.
The MI will not light up for this diagnosis.
NOTE:

If DTC P1574 is displayed with DTC U1000 or U1001, first perform the trouble diagnosis for DTC
U1000, U1001. Refer to EC-133, "
DTC U1000, U1001 CAN COMMUNICATION LINE" .

If DTC P1574 is displayed with DTC P0500, first perform the trouble diagnosis for DTC P0500.
Refer to EC-276, "
DTC P0500 VSS" .

If DTC P1574 is displayed with DTC P0605, first perform the trouble diagnosis for DTC P0605.
Refer to EC-283, "
DTC P0605 ECM" .
DTC Confirmation ProcedureEBS01FAL
CAUTION:
Always drive vehicle at a safe speed.
NOTE:
If DTC Confirmation Procedure has been previously conducted, always turn ignition switch OFF and wait at
least 10 seconds before conducting the next test.
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.
DTC No.Trouble Diagnosis
NameDTC Detecting Condition Possible Cause
P1574
1574ASCD vehicle speed
sensorECM 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)

Harness or connectors
(Revolution sensor circuit is open or shorted)

Harness or connectors
(Wheel sensor circuit is open or shorted.)

TCM

ESP/TCS/ABS control unit (models with ESP)

“ABS actuator and electric unit (control unit)”
(models without ESP)

Combination meter

Wheel sensor

Revolution sensor

ECM