2009 NISSAN LATIO ignition

DTC P1572 ASCD BRAKE SWITCH
EC-1429
< SERVICE INFOMATION >
[MR TYPE 2] C
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DTC P1572 ASCD BRAKE SWITCH
Component Description INFOID:0000000004500308
When the brake pedal is depressed, ASCD brake switch (2) is
turned OFF and stop lamp switch (1) is turned ON. ECM detects the
state of the brake pedal by this input of two kinds (ON/OFF signal).
Refer to EC-1033 for the ASCD function.
CONSULT-III Reference Val ue in Data Monitor Mode INFOID:0000000004500309
Specification data are reference values.
On Board Diagnosis Logic INFOID:0000000004500310
This self-diagnosis has the on e trip detection logic.
The MIL will not light up for this diagnosis.
NOTE:
• If DTC P1572 is displayed with DT C P0605, first perform the trouble diagnosis for DTC P0605. Refer
to EC-1393 .
• 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 igniti on switch OFF. And even when ma lfunction A is detected in two
consecutive trips, DTC is not stored in ECM memory. BBIA0708E
MONITOR ITEM CONDITION SPECIFICATION
BRAKE SW1
(ASCD brake switch) • Ignition switch: ON• Brake pedal: Fully released (A/T, CVT)
• Brake pedal and clutch pedal: Fully re- leased (M/T) ON
• Brake pedal: Slightly depressed (A/T, CVT)
• Brake pedal and/or clutch pedal: Slight- ly depressed (M/T) OFF
BRAKE SW2
(Stop lamp switch) • Ignition switch: ONBrake pedal: Fully released OFF
Brake pedal: Slightly depressed ON DTC No.
Trouble diagnosis
name DTC detecting condition Possible cause
P1572
1572 ASCD brake switch A)
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
(Stop lamp switch circuit is shorted.)
• Harness or connectors (ASCD brake switch circuit is shorted.)
• Harness or connectors
(ASCD clutch switch circuit is shorted.)
(M/T)
• Stop lamp switch
• ASCD brake switch
• ASCD clutch switch (M/T)
• Incorrect stop lamp switch installation
• Incorrect ASCD brake switch installation
• Incorrect ASCD clutch switch installation (M/T)
• ECM
B)
ASCD brake switch signal is not sent to ECM
for extremely long time while the vehicle is
driving

EC-1432< SERVICE INFOMATION >
[MR TYPE 2]
DTC P1572 ASCD BRAKE SWITCH
Diagnosis Procedure INFOID:00000000045003131.
CHECK OVERALL FUNCTION-I
With CONSULT-III
1. Turn ignition switch ON.
2. Select “BRAKE SW1” in “DAT A MONITOR” mode with CONSULT-III.
3. Check “BRAKE SW1” indication under the following conditions.
M/T models
A/T and CVT models
Without CONSULT-III
1. Turn ignition switch ON.
2. Check voltage between ECM terminal 100 and ground under the following conditions.
M/T models
A/T and CVT models
OK or NG OK >> GO TO 2.
NG (M/T models) >>GO TO 3.
NG (A/T and CVT models) >>GO TO 4. 2.
CHECK OVERALL FUNCTION-II
With CONSULT-III
Check “BRAKE SW2” indication in “DATA MONITOR” mode. TERMI-
NAL NO. WIRE
COLOR ITEM CONDITION DATA (DC Voltage)
99 R Stop lamp switch [Ignition switch: ON]
• Brake pedal: Fully released Approximately 0V
[Ignition switch: ON]
• Brake pedal: Slightly depressed BATTERY VOLTAGE
(11 - 14V)
100 G ASCD brake switch • Brake pedal: Slightly depressed (A/T, CVT)
• Brake pedal and/or clutch pedal: Slightly de-
pressed (M/T) Approximately 0V
• Brake pedal: Fully released (A/T, CVT)
• Brake pedal and clutch pedal: Fully released (M/T) BATTERY VOLTAGE
(11 - 14V) CONDITION INDICATION
Clutch pedal and/or brake pedal: Slightly depressed OFF
Clutch pedal and brake pedal: Fully released ON
CONDITION INDICATION
Brake pedal: Slightly depressed OFF
Brake pedal: Fully released ON
CONDITION VOLTAGE
Clutch pedal and/or brake pedal: Slightly depressed Approximately 0V
Clutch pedal and brake pedal: Fully released Battery voltage
CONDITION VOLTAGE
Brake pedal: Slightly depressed Approximately 0V
Brake pedal: Fully released Battery voltage PBIB3315E

DTC P1572 ASCD BRAKE SWITCH
EC-1433
< SERVICE INFOMATION >
[MR TYPE 2] C
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Without CONSULT-III
Check voltage between ECM terminal 99 and ground under the fol-
lowing conditions.
OK or NG OK >> GO TO 15.
NG >> GO TO 11. 3.
CHECK ASCD CLUTCH SWITCH POWER SUPPLY CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect ASCD clutch switch (1) harness connector.
- Clutch pedal (2)
3. Turn ignition switch ON.
4. Check voltage between ASCD clutch switch terminal 1 and ground under the following conditions with CONSULT-III or
tester.
OK or NG OK >> GO TO 9.
NG >> GO TO 4. 4.
CHECK ASCD BRAKE SWITCH POWER SUPPLY
1. Turn ignition switch OFF. CONDITION INDICATION
Brake pedal: Fully released OFF
Brake pedal: Slightly depressed ON CONDITION VOLTAGE
Brake pedal: Fully released Approximately 0V
Brake pedal: Slightly depressed Battery voltage PBIB0311E
BBIA0709E
CONDITION VOLTAGE
Brake pedal: Fully released Battery voltage
Brake pedal: Slightly depressed Approx. 0V PBIB0857E

EC-1434< SERVICE INFOMATION >
[MR TYPE 2]
DTC P1572 ASCD BRAKE SWITCH
2. Disconnect ASCD brake switch (2) harness connector.
- Stop lamp switch (1)
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 (M/T models) >>GO TO 6.
OK (A/T and CVT m odels) >>GO TO 7.
NG >> GO TO 5. 5.
DETECT MALFUNCTIONING PART
Check the following.
• Harness connectors M69, E7
• 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. 6.
CHECK ASCD BRAKE SWITCH INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch OFF.
2. Check harness continuity between ASCD brake switch terminal 2 and ASCD clutch 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. 7.
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 100 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 8.
NG >> Repair open circuit or short to ground or short to power in harness or connectors. 8.
CHECK ASCD BRAKE SWITCH
Refer to EC-1436, " Component Inspection " . BBIA0708E
Voltage: Battery voltage
PBIB0857E
Continuity should exist.
Continuity should exist.

DTC P1572 ASCD BRAKE SWITCH
EC-1435
< SERVICE INFOMATION >
[MR TYPE 2] C
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OK or NG OK >> GO TO 15.
NG >> Replace ASCD brake switch. 9.
CHECK ASCD CLUTCH 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 100 and ASCD clutch 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 10.
NG >> Repair open circuit or short to ground or short to power in harness or connectors. 10.
CHECK ASCD CLUTCH SWITCH
Refer to EC-1436, " Component Inspection "
OK or NG OK >> GO TO 15.
NG >> Replace ASCD clutch switch. 11.
CHECK STOP LAMP SWITCH POWER SUPPLY CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect stop lamp switch (1) harness connector.
- ASCD brake switch (2)
3. Check voltage between stop lamp switch terminal 1 and ground with CONSULT-III or tester.
OK or NG OK >> GO TO 13.
NG >> GO TO 12. 12.
DETECT MALFUNCTIONING PART
Check the following.
• Harness connectors M69, E7
• 10A fuse Continuity should exist.
BBIA0708E
Voltage: Battery voltage PBIB3317E

EC-1436< SERVICE INFOMATION >
[MR TYPE 2]
DTC P1572 ASCD BRAKE SWITCH
• 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 SI GNAL CIRCUIT FOR OPEN AND SHORT
1. Disconnect ECM harness connector.
2. Check harness continuity between ECM terminal 99 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-1436, " Component Inspection "
OK or NG OK >> GO TO 15.
NG >> Replace stop lamp switch. 15.
CHECK INTERMITTENT INCIDENT
Refer to EC-1138 .
>> INSPECTION END
Component Inspection INFOID:0000000004500314
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 , and
perform step 3 again.
ASCD CLUTCH SWITCH
1. Turn ignition switch OFF.
2. Disconnect ASCD clutch switch harness connector. Continuity should exist.
Condition Continuity
Brake pedal: Fully released. Should exist.
Brake pedal: Slightly depressed. Should not exist. SEC023D

DTC P1572 ASCD BRAKE SWITCH
EC-1437
< SERVICE INFOMATION >
[MR TYPE 2] C
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M A EC
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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 , 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 , and perform step 3 again.
Condition Continuity
Clutch pedal: Fully released. Should exist.
Clutch pedal: Slightly depressed. Should not exist. SEC023D
Condition Continuity
Brake pedal: Fully released. Should not exist.
Brake pedal: Slightly depressed. Should exist. PBIB3318E

for ASCD functions.
On Board Diagn osis Logic INFOID:0000000004500316
NOTE:
• If DTC P1574 is displayed with DTC UXXXX, first perform the tr ouble diagnosis for DTC UXXXX.
• If DTC P1574 is displayed with DTC P0500, first pe rform the trouble diagnosis for DTC P0500. Refer
to EC-1387 .
This self-diagnosis has the one trip detection logic.
The MIL will not light up for this diagnosis.
DTC Confirmation Procedure INFOID:0000000004500317
CAUTION:
Always drive vehicle at a safe speed.
NOTE:
If DTC Confirmation Procedure has been previously conduc ted, 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.
1. Start engine.
2. Drive the vehicle at more than 40 km/h (25MPH).
3. Check DTC.
4. If DTC is detected, go to EC-1438, " Diagnosis Procedure " .
Diagnosis Procedure INFOID:0000000004500318 (A/T) or
CVT-209 (CVT).
OK or NG OK >> GO TO 2.
NG >> Perform trouble shooting relevant to DTC indicated. .
OK or NG OK >> GO TO 3.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
(CAN communication line is open or shorted.)
• Harness or connectors (Combination meter circuit is open or shorted.)
• TCM
• ABS actuator and electric unit (control unit)
• Combination meter
• ECM