2008 INFINITI FX35 ignition switch

EC-468
< SERVICE INFORMATION >[VQ35DE]
DTC P1572 ICC BRAKE SWITCH
Diagnosis Procedure
INFOID:0000000001326335
1.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.
Without CONSULT-III
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.
2.CHECK OVERALL FUNCTION-II
With CONSULT-III
Check “BRAKE SW2” indication in “DATA MONITOR” mode.
Without CONSULT-III
TERMI-NAL NO. WIRE
COLOR ITEM CONDITION DATA (DC Voltage)
101 P/L Stop lamp switch [Ignition switch: OFF]
 Brake pedal: Fully released
Approximately 0V
[Ignition switch: OFF]
 Brake pedal: Slightly depressed BATTERY VOLTAGE
(11 - 14V)
108 SB ICC brake switch [Ignition switch: ON]
 Brake pedal: Slightly depressed
Approximately 0V
[Ignition switch: ON]
 Brake pedal: Fully released BATTERY VOLTAGE
(11 - 14V)
CONDITION INDICATION
Brake pedal: Slightly depressed OFF
Brake pedal: Fully released ON
CONDITION VOLTAGE
Brake pedal: Slightly depressed Approximately 0V
Brake pedal: Fully released Battery voltage
MBIB0061E
CONDITION INDICATION
Brake pedal: Fully released OFF
Brake pedal: Slightly depressed ON
3AA93ABC3ACD3AC03ACA3AC03AC63AC53A913A773A893A873A873A8E3A773A983AC73AC93AC03AC3
3A893A873A873A8F3A773A9D3AAF3A8A3A8C3A863A9D3AAF3A8B3A8C

DTC P1572 ICC BRAKE SWITCHEC-469
< SERVICE INFORMATION > [VQ35DE]
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Check voltage between ECM terminal 101 and ground under the fol-
lowing conditions.
OK or NG
OK >> GO TO 17.
NG >> GO TO 12.
3.CHECK DTC WITH ICC UNIT
Refer to ACS-35
.
OK or NG
OK >> GO TO 4.
NG >> Repair or replace.
4.CHECK ICC BRAKE SWITCH CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect ICC brake hold relay.
3. Turn ignition switch ON.
4. Check voltage between ICC brake hold relay terminal 3 and ground with CONSULT-III or tester.
OK or NG
OK >> GO TO 9.
NG >> GO TO 5.
5.CHECK ICC BRAKE SWITCH POWER SUPPLY CIRCUIT
1. Turn ignition switch OFF.
CONDITION VOLTAGE
Brake pedal: Fully released Approximately 0V
Brake pedal: Slightly depressed Battery voltage
PBIB1537E
PBIB1531E
Voltage: Battery voltage
PBIB1538E
3AA93ABC3ACD3AC03ACA3AC03AC63AC53A913A773A893A873A873A8E3A773A983AC73AC93AC03AC3
3A893A873A873A8F3A773A9D3AAF3A8A3A8C3A863A9D3AAF3A8B3A8C

EC-470
< SERVICE INFORMATION >[VQ35DE]
DTC P1572 ICC BRAKE SWITCH
2. Disconnect ICC brake switch harness connector.
3. Turn ignition switch ON.
4. Check voltage between ICC brake switch terminal 1 and ground
with CONSULT-III 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 E201
 10A fuse
 Harness for open or short between ICC brake switch and fuse
>> Repair open circuit or short to ground or short to power in harness or connectors.
7.CHECK ICC BRAKE SWITCH INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT-I
1. Turn ignition switch OFF.
2. Check harness continuity between ICC brake hold rela y terminal 3 and ICC brake 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 8.
NG >> Repair open circuit or short to ground or short to power in harness or connectors.
8.CHECK ICC BRAKE SWITCH
Refer to EC-472, "
Component Inspection".
OK or NG
OK >> GO TO 17.
NG >> Replace ICC brake switch.
9.CHECK ICC BRAKE SWITCH INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT-II
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check harness continuity between ICC brake hold relay terminal 4 and ECM terminal 108. Refer Wiring Diagram.
4. Also check harness for short to ground and short to power.
PBIB1539E
Voltage: Battery voltage
PBIB0857E
Continuity should exist.
Continuity should exist.
3AA93ABC3ACD3AC03ACA3AC03AC63AC53A913A773A893A873A873A8E3A773A983AC73AC93AC03AC3
3A893A873A873A8F3A773A9D3AAF3A8A3A8C3A863A9D3AAF3A8B3A8C

DTC P1572 ICC BRAKE SWITCHEC-471
< SERVICE INFORMATION > [VQ35DE]
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OK or NG
OK >> GO TO 11.
NG >> GO TO 10.
10.DETECT MALFUNCTIONING PART
Check the following.
 Harness connectors E211, M41
 Harness for open or short between ICC brake hold relay and ECM
>> Repair open circuit or short to ground or short to power in harness or connectors.
11 .CHECK ICC BRAKE HOLD RELAY
Refer to EC-472, "
Component Inspection".
OK >> GO TO 17.
NG >> Replace ICC brake hold relay.
12.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 14.
NG >> GO TO 13.
13.DETECT MALFUNCTIONING PART
Check the following.
 Fuse block (J/B) connector E201
 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.
14.CHECK STOP LAMP SWITCH INPUT SI GNAL 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.
PBIB1539E
Voltage: Battery voltage
PBIB1184E
Continuity should exist.
3AA93ABC3ACD3AC03ACA3AC03AC63AC53A913A773A893A873A873A8E3A773A983AC73AC93AC03AC3
3A893A873A873A8F3A773A9D3AAF3A8A3A8C3A863A9D3AAF3A8B3A8C

EC-472
< SERVICE INFORMATION >[VQ35DE]
DTC P1572 ICC BRAKE SWITCH
OK or NG
OK >> GO TO 16.
NG >> GO TO 15.
15.DETECT MALFUNCTIONING PART
Check the following.
 Harness connectors E211, M41
 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.
16.CHECK STOP LAMP SWITCH
Refer to EC-472, "
Component Inspection"
OK or NG
OK >> GO TO 17.
NG >> Replace stop lamp switch.
17.CHECK INTERMITTENT INCIDENT
Refer to EC-139
.
>> INSPECTION END
Component InspectionINFOID:0000000001326336
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.
If NG, adjust ICC brake switch installation, refer to BR-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-5
, and
perform step 3 again.
ICC BRAKE HOLD RELAY
1. Apply 12V direct current between ICC brake hold relay terminals 1 and 2.
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
PBIB1185E
3AA93ABC3ACD3AC03ACA3AC03AC63AC53A913A773A893A873A873A8E3A773A983AC73AC93AC03AC3
3A893A873A873A8F3A773A9D3AAF3A8A3A8C3A863A9D3AAF3A8B3A8C

EC-474
< SERVICE INFORMATION >[VQ35DE]
DTC P1572 ASCD BRAKE SWITCH
DTC P1572 ASCD BRAKE SWITCH
Component DescriptionINFOID:0000000001326337
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-37
for the ASCD function.
CONSULT-III Reference Value in Data Monitor ModeINFOID:0000000001326338
Specification data are reference values.
On Board Diagn osis LogicINFOID:0000000001326339
This self-diagnosis has the one trip detection logic.
 The MIL will not light up for this self-diagnosis.
NOTE:
 If DTC P1572 is displayed with DTC P0605, first pe rform the trouble diagnosis for DTC P0605. Refer
to EC-422
This self-diagnosis has the one tr ip 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.
DTC Confirmation ProcedureINFOID:0000000001326340
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.
 Procedure for malfunction B is not described here. It takes extremely long time to complete procedure for
malfunction B. By performing procedur e for malfunction A, the incident that causes malfunction B can be
detected.
PBIB1605E
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
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.)
 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
3AA93ABC3ACD3AC03ACA3AC03AC63AC53A913A773A893A873A873A8E3A773A983AC73AC93AC03AC3
3A893A873A873A8F3A773A9D3AAF3A8A3A8C3A863A9D3AAF3A8B3A8C

DTC P1572 ASCD BRAKE SWITCHEC-477
< SERVICE INFORMATION > [VQ35DE]
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Diagnosis ProcedureINFOID:0000000001326342
1.CHECK OVERALL FUNCTION-I
With CONSULT-III
1. Turn ignition switch ON.
2. Select “BRAKE SW1” in “DATA MONITOR” mode with CONSULT-III.
3. Check “BRAKE SW1” indication under the following conditions.
Without CONSULT-III
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.
2.CHECK OVERALL FUNCTION-II
With CONSULT-III
Check “BRAKE SW2” indication in “DATA MONITOR” mode.
Without CONSULT-III
Check voltage between ECM terminal 101 and ground under the following conditions.
TER-
MI-
NAL
NO. WIRE
COLOR ITEM CONDITION DATA (DC Voltage)
101 P/L Stop lamp switch [Ignition switch: OFF]
 Brake pedal: Fully released
Approximately 0V
[Ignition switch: OFF]
 Brake pedal: Slightly depressed BATTERY VOLTAGE
(11 - 14V)
108 SB ASCD brake switch [Ignition switch: ON]
 Brake pedal: Slightly depressed
Approximately 0V
[Ignition switch: ON]
 Brake pedal: Fully released BATTERY VOLTAGE
(11 - 14V)
CONDITION INDICATION
Brake pedal: Slightly depressed OFF
Brake pedal: Fully released ON
CONDITION VOLTAGE
Brake pedal: Slightly depressed Approximately 0V
Brake pedal: Fully released Battery voltage
MBIB0061E
CONDITION INDICATION
Brake pedal: Fully released OFF
Brake pedal: Slightly depressed ON
3AA93ABC3ACD3AC03ACA3AC03AC63AC53A913A773A893A873A873A8E3A773A983AC73AC93AC03AC3
3A893A873A873A8F3A773A9D3AAF3A8A3A8C3A863A9D3AAF3A8B3A8C

EC-478
< SERVICE INFORMATION >[VQ35DE]
DTC P1572 ASCD BRAKE SWITCH
OK or NG
OK >> GO TO 13.
NG >> GO TO 8.
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.
 Fuse block (J/B) connector E201
 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 7.
NG >> GO TO 6.
CONDITION VOLTAGE
Brake pedal: Fully released Approximately 0V
Brake pedal: Slightly depressed Battery voltage
MBIB0060E
PBIB1605E
Voltage: Battery voltage
PBIB0857E
Continuity should exist.
3AA93ABC3ACD3AC03ACA3AC03AC63AC53A913A773A893A873A873A8E3A773A983AC73AC93AC03AC3
3A893A873A873A8F3A773A9D3AAF3A8A3A8C3A863A9D3AAF3A8B3A8C