2007 INFINITI M35 brake light

DTC P1572 ICC BRAKE SWITCH
EC-575
[VQ35DE]
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Revision: 2007 April2007 M35/M45
Component InspectionNBS00556
ICC BRAKE SWITCH
1. Turn ignition switch OFF.
2. Disconnect ICC brake switch harness connector.
3. Check continuity between ICC brake switch terminals 1 and 2
under the following conditions.
4. If NG, adjust ICC brake switch installation, refer to BR-6,
"BRAKE 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.
4. If NG, adjust stop lamp switch installation, refer to BR-6,
"BRAKE PEDAL" , and perform step 3 again.
ICC BRAKE HOLD RELAY
1. Check continuity between ICC brake hold relay terminals 3 and
5 under the following conditions.
2. If NG, replace ICC brake hold relay.
Condition Continuity
Brake pedal: Fully released Should exist
Brake pedal: Slightly depressed Should not exist
PBIB1536E
Condition Continuity
Brake pedal: Fully released Should not exist
Brake pedal: Slightly depressed Should exist
PBIA9489J
Condition Continuity
12V direct current supply between terminals
1 and 2Should not exist
No current supply Should exist
PBIB0098E

EC-576
[VQ35DE]
DTC P1572 ASCD BRAKE SWITCH
Revision: 2007 April2007 M35/M45
DTC P1572 ASCD BRAKE SWITCHPFP:25320
Component DescriptionNBS00557
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-36, "
AUTOMATIC SPEED CONTROL DEVICE (ASCD)"
for the ASCD function.
CONSULT-II Reference Value in Data Monitor ModeNBS00558
Specification data are reference values.
On Board Diagnosis LogicNBS00559
This self-diagnosis has the one trip detection logic.
The MIL 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-483, "
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.
PBIB2705E
MONITOR ITEM CONDITION SPECIFICATION
BRAKE SW1
(ASCD brake switch)

Ignition switch: ONBrake pedal: Fully released ON
Brake pedal: Slightly depressed OFF
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 30 km/h
(19 MPH), ON signals from the stop lamp
switch and the ASCD brake switch are
sent to the 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.)

Stop lamp switch

ASCD brake switch

Incorrect stop lamp switch installation

Incorrect ASCD brake switch installation

ECM B)ASCD brake switch signal is not sent to
ECM for extremely long time while the
vehicle is driving.

DTC P1572 ASCD BRAKE SWITCH
EC-577
[VQ35DE]
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Revision: 2007 April2007 M35/M45
DTC Confirmation ProcedureNBS0055A
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 (VDC switch OFF).
2. Select “DATA MONITOR” mode with CONSULT-II.
3. Press MAIN switch and make sure that CRUISE lamp lights up.
4. Drive the vehicle for at least 5 consecutive seconds under the
following conditions.
If 1st trip DTC is detected, go to EC-579, "
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 conditions.
6. If 1st trip DTC is detected, go to EC-579, "
Diagnostic Procedure" .
WITH GST
Follow the procedure “WITH CONSULT-II” above.
VHCL SPEED SE More than 30 km/h (19 MPH)
Selector lever Suitable position
PBIB2386E
VHCL SPEED SE More than 30 km/h (19 MPH)
Selector 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.

DTC P1572 ASCD BRAKE SWITCH
EC-579
[VQ35DE]
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Revision: 2007 April2007 M35/M45
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 ProcedureNBS0055C
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.
Without CONSULT-II
1. Turn ignition switch ON.
2. Check voltage between ECM terminal 108 and ground under the
following conditions.
OK or NG
OK >> GO TO 2.
NG >> GO TO 3.
TER-
MINAL
NO.WIRE
COLORITEM CONDITION DATA (DC Voltage)
101 V/R Stop lamp switch[Ignition switch: OFF]

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

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

Brake pedal: Slightly depressedApproximately 0V
[Ignition switch: ON]

Brake pedal: Fully releasedBATTERY VOLTAGE
(11 - 14V)
CONDITION INDICATION
Brake pedal: Slightly depressed OFF
Brake pedal: Fully released ON
SEC011D
CONDITION VOLTAGE
Brake pedal: Slightly depressed Approximately 0V
Brake pedal: Fully released Battery voltage
MBIB0061E

EC-580
[VQ35DE]
DTC P1572 ASCD BRAKE SWITCH
Revision: 2007 April2007 M35/M45
2. CHECK OVERALL FUNCTION-II
With CONSULT-II
Check “BRAKE SW2” indication in “DATA MONITOR” mode.
Without CONSULT-II
Check voltage between ECM terminal 101 and ground under the following conditions.
OK or NG
OK >> GO TO 13.
NG >> GO TO 8.
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
PBIB1537E

DTC P1572 ASCD BRAKE SWITCH
EC-583
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Revision: 2007 April2007 M35/M45
11 . DETECT MALFUNCTIONING PART
Check the following.

Harness connectors E108, M15

Harness for open or short between ECM and stop lamp switch
>> Repair open circuit or short to ground or short to power in harness or connectors.
12. CHECK STOP LAMP SWITCH
Refer to EC-583, "
Component Inspection"
OK or NG
OK >> GO TO 13.
NG >> Replace stop lamp switch.
13. CHECK INTERMITTENT INCIDENT
Refer to EC-153, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
>>INSPECTION END
Component InspectionNBS0055D
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.
4. If NG, adjust ASCD brake switch installation, refer to BR-6,
"BRAKE 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.
4. 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.
PBIB1536E
Condition Continuity
Brake pedal: Fully released. Should not exist.
Brake pedal: Slightly depressed. Should exist.
PBIA9489J

DTC P1805 BRAKE SWITCH
EC-589
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Revision: 2007 April2007 M35/M45
DTC P1805 BRAKE SWITCHPFP:25320
Component DescriptionNBS0055Q
Brake switch signal is applied to the ECM through the stop lamp
switch (1) when the brake pedal is depressed. This signal is used
mainly to decrease the engine speed when the vehicle is driving.

ICC brake switch (models with ICC) (2)

ASCD brake switch (models with ASCD) (2)
CONSULT-II Reference Value in Data Monitor ModeNBS0055R
Specification data are reference values.
On Board Diagnosis LogicNBS0055S
The MIL will not light up for this diagnosis.
FAIL-SAFE MODE
When the malfunction is detected, ECM enters fail-safe mode.
PBIB2705E
MONITOR ITEM CONDITION SPECIFICATION
BRAKE SW

Ignition switch: ONBrake pedal: Fully released OFF
Brake pedal: Slightly depressed ON
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P1805
1805Brake switchA brake switch signal is not sent to ECM for
extremely long time while the vehicle is driving.

Harness or connectors
(Stop lamp switch circuit is open or
shorted.)

Stop lamp switch
Engine operating condition in fail-safe mode
ECM controls the electric throttle control actuator by regulating the throttle opening to a small range.
Therefore, acceleration will be poor.
Vehicle condition Driving condition
When engine is idling Normal
When accelerating Poor acceleration

EC-592
[VQ35DE]
DTC P1805 BRAKE SWITCH
Revision: 2007 April2007 M35/M45
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 ProcedureNBS0055V
ICC MODELS
1. CHECK DTC WITH ICC SENSOR INTEGRATED UNIT
Refer to ACS-40, "
TROUBLE DIAGNOSIS FOR SELF-DIAGNOSTIC ITEMS" .
OK or NG
OK >> GO TO 2.
NG >> Repair or replace.
2. CHECK STOP LAMP SWITCH CIRCUIT
1. Turn ignition switch OFF.
2. Check the stop lamp when depressing and releasing the brake pedal.
OK or NG
OK >> GO TO 5.
NG >> GO TO 3.
TER-
MINAL
NO.WIRE
COLORITEM CONDITION DATA (DC Voltage)
101 V/R Stop lamp switch[Ignition switch: OFF]

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

Brake pedal: Slightly depressedBATTERY VOLTAGE
(11 - 14V)
Brake pedal Stop lamp
Fully released Not illuminated
Slightly depressed Illuminated