INFINITI FX35 2004 Service Manual

EC-1200
[VK45DE]
DTC P1572 ASCD BRAKE SWITCH
Revision: 2004 November 2004 FX35/FX45
DTC Confirmation ProcedureABS00CCI
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 3 and 4 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 indicator 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-1202, "
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-1202, "
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
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.
PBIB2386E

DTC P1572 ASCD BRAKE SWITCH
EC-1201
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Revision: 2004 November 2004 FX35/FX45
Wiring Diagram ABS00CCJ
TBWM0258E

EC-1202
[VK45DE]
DTC P1572 ASCD BRAKE SWITCH
Revision: 2004 November 2004 FX35/FX45
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 ProcedureABS00CCK
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 P/L Stop lamp switch[Ignition switch: OFF]

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

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

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

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

DTC P1572 ASCD BRAKE SWITCH
EC-1203
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Revision: 2004 November 2004 FX35/FX45
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
When brake pedal is fully released OFF
When brake pedal is slightly depressed ON
SEC013D
CONDITION VOLTAGE
When brake pedal is fully released Approximately 0V
When brake pedal is slightly depressed Battery voltage
PBIB1537E

EC-1204
[VK45DE]
DTC P1572 ASCD BRAKE SWITCH
Revision: 2004 November 2004 FX35/FX45
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 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.
6. DETECT MALFUNCTIONING PART
Check the following.

Harness connectors E211, M41

Harness for open or short between ECM and ASCD brake switch
>> Repair open circuit or short to ground or short to power in harness or connectors.
PBIB1506E
Voltage: Battery voltage
PBIB0857E
Continuity should exist.

DTC P1572 ASCD BRAKE SWITCH
EC-1205
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Revision: 2004 November 2004 FX35/FX45
7. CHECK ASCD BRAKE SWITCH
Refer to EC-1206, "
Component Inspection"
OK or NG
OK >> GO TO 13.
NG >> Replace ASCD brake switch.
8. 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 10.
NG >> GO TO 9.
9. DETECT MALFUNCTIONING PART
Check the following.

Fuse block (J/B) connector E201

10A fuse

Joint connector-2

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.
10. 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 12.
NG >> GO TO 11.
PBIB1506E
Voltage: Battery voltage
PBIB1184E
Continuity should exist.

EC-1206
[VK45DE]
DTC P1572 ASCD BRAKE SWITCH
Revision: 2004 November 2004 FX35/FX45
11 . DETECT MALFUNCTIONING PART
Check the following.

Harness connectors E211, M41

Joint connector-2

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-1206, "
Component Inspection"
OK or NG
OK >> GO TO 13.
NG >> Replace stop lamp switch.
13. CHECK INTERMITTENT INCIDENT
Refer to EC-784, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
>>INSPECTION END
Component InspectionABS00CCL
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.
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.
If NG, adjust stop lamp switch installation, refer to BR-6,
"BRAKE PEDAL" , and perform step 3 again.
Condition Continuity
When brake pedal is fully released. Should exist.
When brake pedal is slightly depressed. Should not exist.
PBIB1536E
Condition Continuity
When brake pedal is fully released. Should not exist.
When brake pedal is slightly depressed. Should exist.
PBIB1535E

DTC P1574 ICC VEHICLE SPEED SENSOR
EC-1207
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Revision: 2004 November 2004 FX35/FX45
DTC P1574 ICC VEHICLE SPEED SENSORPFP:31036
Component DescriptionABS00CCM
The ECM receives two vehicle speed signals via CAN communication line. One is sent from “unified meter and
A/C amp.”, and the other is from TCM (Transmission control module). The ECM uses these signals for ICC
control. Refer to ACS-6, "
DESCRIPTION" for ICC functions.
On Board Diagnosis LogicABS00CCN
This self-diagnosis has the one trip detection logic.
The MIL will not light up for this diagnosis.
NOTE:

If DTC P1574 is displayed with DTC U1000, U1001, first perform the trouble diagnosis for DTC
U1000, U1001. Refer to EC-792, "
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-1046, "
DTC P0500 VSS" .
DTC Confirmation ProcedureABS00CCO
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.
WITH CONSULT-II
1. Start engine (VDC switch OFF).
2. Select “DATA MONITOR” mode with CONSULT-II.
3. Drive the vehicle at more than 40 km/h (25MPH).
4. If DTC is detected, go to EC-1208, "
Diagnostic Procedure" .
WITH GST
Follow the procedure “WITH CONSULT-II” above.
DTC No.Trouble diagnosis
nameDTC detecting condition Possible cause
P1574
1574ICC 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.)

TCM

ABS actuator and electric unit (control unit)

Wheel sensor

Unified meter and A/C amp.

ECM
SEF058Y

EC-1208
[VK45DE]
DTC P1574 ICC VEHICLE SPEED SENSOR
Revision: 2004 November 2004 FX35/FX45
Diagnostic ProcedureABS00CCP
1. CHECK DTC WITH TCM
Check DTC with TCM. Refer to AT- 3 8 , "
ON BOARD DIAGNOSTIC (OBD) SYSTEM" .
OK or NG
OK >> GO TO 2.
NG >> Perform trouble shooting relevant to DTC indicated.
2. CHECK DTC WITH “ABS ACTUATOR AND ELECTRIC UNIT (CONTROL UNIT)”
Refer to BRC-12, "
TROUBLE DIAGNOSIS" .
OK or NG
OK >> GO TO 3.
NG >> Repair or replace.
3. CHECK DTC WITH “UNIFIED METER AND A/C AMP.”
Check combination meter function.
Refer to DI-28, "
UNIFIED METER AND A/C AMP" .
>>INSPECTION END

DTC P1574 ASCD VEHICLE SPEED SENSOR
EC-1209
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Revision: 2004 November 2004 FX35/FX45
DTC P1574 ASCD VEHICLE SPEED SENSORPFP:31036
Component DescriptionABS00CCQ
The ECM receives two vehicle speed sensor signals via CAN communication line. One is sent from “unified
meter and A/C amp.”, and the other is from TCM (Transmission control module). The ECM uses these signals
for ASCD control. Refer to EC-1334, "
AUTOMATIC SPEED CONTROL DEVICE (ASCD)" for ASCD func-
tions.
On Board Diagnosis LogicABS00CCR
This self-diagnosis has the one trip detection logic.
The MIL will not light up for this diagnosis.
NOTE:

If DTC P1574 is displayed with DTC U1000, U1001, first perform the trouble diagnosis for DTC
U1000, U1001. Refer to EC-792, "
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-1046, "
DTC P0500 VSS"

If DTC P1574 is displayed with DTC P0605, first perform the trouble diagnosis for DTC P0605.
Refer to EC-1057, "
DTC P0605 ECM"
DTC Confirmation ProcedureABS00CCS
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.
WITH CONSULT-II
1. Start engine (VDC switch OFF).
2. Select “DATA MONITOR” mode with CONSULT-II.
3. Drive the vehicle at more than 40 km/h (25 MPH).
4. If DTC is detected, go to EC-1210, "
Diagnostic Procedure" .
WITH GST
Follow the procedure “WITH CONSULT-II” above.
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.)

Unified meter and A/C amp.

ABS actuator and electric unit (control unit)

Wheel sensor

TCM

ECM
SEF058Y