2005 INFINITI FX35 Ignition switch

DTC P1572 ICC BRAKE SWITCH EC-1263
[VK45DE]
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Revision: 2005 July 2005 FX
DTC Confirmation ProcedureABS00E5G
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-1265, "
Diagnostic Proce-
dure" .
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-1265, "
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 location Depress the brake pedal for more than
five seconds so as not to come off from
the above-mentioned vehicle speed.

DTC P1572 ICC BRAKE SWITCH EC-1265
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Revision: 2005 July 2005 FX
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 ProcedureABS00DCG
1. CHECK OVERALL FUNCTION-I
With CONSULT-II
1. Turn ignition switch ON.
2. Select “BRAKE SW1” in “DATA MONITOR” mode with CON- SULT-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
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
When brake pedal: Slightly depressed OFF
When brake pedal: Fully released ON
SEC011D
CONDITION VOLTAGE
When brake pedal: Slightly depressed Approximately 0V
When brake pedal: Fully released Battery voltage
MBIB0061E

DTC P1572 ICC BRAKE SWITCH EC-1267
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Revision: 2005 July 2005 FX
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-II 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.
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-II or tester.
OK or NG
OK >> GO TO 7.
NG >> GO TO 6.
PBIB1531E
Voltage: Battery voltage
PBIB1538E
PBIB2558E
Voltage: Battery voltage
PBIB0857E

EC-1268
[VK45DE]
DTC P1572 ICC BRAKE SWITCH
Revision: 2005 July 2005 FX
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 relay 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-1270, "
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.
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-1270, "
Component Inspection" .
OK >> GO TO 17.
NG >> Replace ICC brake hold relay. Continuity should exist.
Continuity should exist.

DTC P1572 ICC BRAKE SWITCH EC-1269
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Revision: 2005 July 2005 FX
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 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 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.
PBIB2558E
Voltage: Battery voltage
PBIB1184E
Continuity should exist.

EC-1270
[VK45DE]
DTC P1572 ICC BRAKE SWITCH
Revision: 2005 July 2005 FX
16. CHECK STOP LAMP SWITCH
Refer to EC-1270, "
Component Inspection"
OK or NG
OK >> GO TO 17.
NG >> Replace stop lamp switch.
17. CHECK INTERMITTENT INCIDENT
Refer to EC-854, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
>> INSPECTION END
Component InspectionABS00DCH
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. Apply 12V direct current between ICC brake hold relay terminals 1 and 2.
2. Check continuity between relay terminals 3 and 4, 6 and 7 under the following conditions.
3. If NG, replace ICC brake hold relay.
Condition Continuity
When brake pedal: Fully released. Should exist.
When brake pedal: Slightly depressed. Should not exist.
PBIB1536E
Condition Continuity
When brake pedal: Fully released. Should not exist.
When brake pedal: Slightly depressed. Should exist.
PBIB1535E
Condition Between terminals Continuity
12V direct current supply
between terminals 1 and 2 3 and 4 Should not exist
6 and 7 Should exist
No current supply 3 and 4 Should exist
6 and 7 Should not exist
MBIB0063E

DTC P1572 ASCD BRAKE SWITCH EC-1271
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Revision: 2005 July 2005 FX
DTC P1572 ASCD BRAKE SWITCHPFP:25320
Component DescriptionABS007UM
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-727, "
AUTOMATIC SPEED CONTROL DEVICE
(ASCD)" for the ASCD function.
CONSULT-II Reference Value in Data Monitor ModeABS007UN
Specification data are reference values.
On Board Diagnosis LogicABS00E5H
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-1134, "
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.
PBIB2558E
MONITOR ITEM CONDITION SPECIFICATION
BRAKE SW1
(ASCD brake switch)

Ignition switch: ON Brake pedal: Fully released ON
Brake pedal: Slightly depressed OFF
BRAKE SW2
(stop lamp switch)

Ignition switch: ON Brake 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 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.

EC-1272
[VK45DE]
DTC P1572 ASCD BRAKE SWITCH
Revision: 2005 July 2005 FX
DTC Confirmation ProcedureABS00E5I
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-1274, "
Diagnostic Proce-
dure" .
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-1274, "
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 location Depress the brake pedal for more than
five seconds so as not to come off from
the above-mentioned vehicle speed.