control INFINITI FX35 2004 Service Manual

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

EC-1210
[VK45DE]
DTC P1574 ASCD VEHICLE SPEED SENSOR
Revision: 2004 November 2004 FX35/FX45
Diagnostic ProcedureABS00CCT
1. CHECK DTC WITH TCM
Check DTC with TCM. Refer to AT- 3 8
.
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.”
Refer to DI-28, "
UNIFIED METER AND A/C AMP" .
>>INSPECTION END

EC-1216
[VK45DE]
DTC P1720 VEHICLE SPEED SENSOR (A/T OUTPUT)
Revision: 2004 November 2004 FX35/FX45
DTC P1720 VEHICLE SPEED SENSOR (A/T OUTPUT)PFP:31036
DescriptionABS00CD1
NOTE:
If DTC P1720 is displayed with DTC U1000 or U1001, first perform the trouble diagnosis for DTC U1000,
U1001. Refer to EC-792, "
DTC U1000, U1001 CAN COMMUNICATION LINE" .
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). ECM uses these two signals for
engine control.
CONSULT-II Reference Value in Data Monitor ModeABS00CD2
Specification data are reference values.
On Board Diagnosis LogicABS00CD3
The MIL will not light up for this diagnosis.
DTC Confirmation ProcedureABS00CD4
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.
WITH CONSULT-II
1. Turn ignition switch ON.
2. Select “DATA MONITOR” mode with CONSULT-II.
3. Start engine.
4. Drive vehicle at a speed of 20 km/h (12 MPH) or more for at least 5 seconds without brake pedal depress-
ing.
5. If 1st trip DTC is detected, go to EC-1217, "
Diagnostic Procedure" .
WITH GST
Follow the procedure “WITH CONSULT-II” above.
MONITOR ITEM CONDITION SPECIFICATION
VEH SPEED SE

Turn drive wheels and compare the CONSULT-II value with speedometer
indicationAlmost the same speed as the
speedometer indication
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P1720
1720Vehicle speed sensor
(A/T output)ECM detects a difference between two
vehicle speed sensor signals is out of the
specified range.

Harness or connectors
(The CAN communication line is open or
shorted)

Harness or connectors
(Revolution sensor circuit is open or shorted)

Harness or connectors
(Wheel sensor circuit is open or shorted.)

TCM

ABS actuator and electric unit (control unit)

Unified meter and A/C amp.

DTC P1720 VEHICLE SPEED SENSOR (A/T OUTPUT)
EC-1217
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Revision: 2004 November 2004 FX35/FX45
Diagnostic ProcedureABS00CD5
1. CHECK DTC WITH TCM
Check DTC with TCM. Refer to AT- 4 2 , "
TROUBLE DIAGNOSIS" .
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)”
Check DTC with “ABS actuator and electric unit (control unit)”. Refer to BRC-12, "
TROUBLE DIAGNOSIS" .
OK or NG
OK >> GO TO 3.
NG >> Perform trouble shooting relevant to DTC indicated.
3. CHECK “UNIFIED METER AND A/C AMP.”
Check combination meter function. Refer to DI-28, "
UNIFIED METER AND A/C AMP" .
>>INSPECTION END

EC-1218
[VK45DE]
DTC P1780 SHIFT CHANGE SIGNAL
Revision: 2004 November 2004 FX35/FX45
DTC P1780 SHIFT CHANGE SIGNALPFP:31036
DescriptionABS00CD6
NOTE:
If DTC P1780 is displayed with DTC U1000 or U1001, first perform the trouble diagnosis for DTC U1000,
U1001. Refer to EC-792, "
DTC U1000, U1001 CAN COMMUNICATION LINE" .
ECM receives current gear position signal, next gear position signal, shift change signal, shift pattern signal
through CAN communication line from TCM (Transmission control module). ECM uses these four signals for
engine control.
On Board Diagnosis LogicABS00CD7
The MIL will not light up for this diagnosis.
DTC Confirmation ProcedureABS00CD8
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.
WITH CONSULT-II
1. Perform DTC confirmation procedure for DTC P1754, refer to AT- 1 5 4 , "DTC Confirmation Procedure" .
2. If 1st trip DTC is detected, go to EC-1218, "
Diagnostic Procedure" .
WITH GST
Follow the procedure “WITH CONSULT-II” above.
Diagnostic ProcedureABS00CD9
1. CHECK DTC WITH TCM
Check DTC with TCM. Refer to AT- 4 2 , "
TROUBLE DIAGNOSIS" .
OK or NG
OK >> GO TO 2.
NG >> Perform trouble shooting relevant to DTC indicated.
2. CHECK TCM FUNCTION
Refer to AT- 4 2 , "
TROUBLE DIAGNOSIS" .
OK or NG
OK >> GO TO 3.
NG >> Replace TCM. Refer to AT- 7 , "
PRECAUTIONS" .
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P1780
1780Shift change signalA)The next gear position signal and the current gear
position signal are not in the normal pattern com-
pared with the shift pattern signal,

Harness or connectors
(CAN communication line circuit
is open or shorted)

TCM

A/T assembly B)The next gear position signal and the current gear
position signal are different even through the shift
change signal is OFF.

EC-1220
[VK45DE]
DTC P1805 BRAKE SWITCH
Revision: 2004 November 2004 FX35/FX45
DTC P1805 BRAKE SWITCHPFP:25320
DescriptionABS00CDA
Brake switch signal is applied to the ECM through the stop lamp switch when the brake pedal is depressed.
This signal is used mainly to decrease the engine speed when the vehicle is driving.
CONSULT-II Reference Value in Data Monitor ModeABS00CDB
Specification data are reference values.
On Board Diagnosis LogicABS00CDC
The MIL will not light up for this diagnosis.
FAIL-SAFE MODE
When the malfunction is detected, the ECM enters fail-safe mode.
DTC Confirmation ProcedureABS00CDD
WITH CONSULT-II
1. Turn ignition switch ON.
2. Fully depress the brake pedal for at least 5 seconds.
3. Erase the DTC with CONSULT-II.
4. Select “DATA MONITOR” mode with CONSULT-II.
5. If 1st trip DTC is detected, go to EC-1222, "
Diagnostic Proce-
dure" .
WITH GST
Follow the procedure “WITH CONSULT-II” above.
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
SEF058Y

DTC P2122, P2123 APP SENSOR
EC-1225
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Revision: 2004 November 2004 FX35/FX45
DTC P2122, P2123 APP SENSORPFP:18002
Component DescriptionABS00CDH
The accelerator pedal position sensor is installed on the upper end
of the accelerator pedal assembly. The sensor detects the accelera-
tor position and sends a signal to the ECM.
Accelerator pedal position sensor has two sensors. These sensors
are a kind of potentiometers which transform the accelerator pedal
position into output voltage, and emit the voltage signal to the ECM.
In addition, these sensors detect the opening and closing speed of
the accelerator pedal and feed the voltage signals to the ECM. The
ECM judges the current opening angle of the accelerator pedal from
these signals and controls the throttle control motor based on these
signals.
Idle position of the accelerator pedal is determined by the ECM
receiving the signal from the accelerator pedal position sensor. The ECM uses this signal for the engine oper-
ation such as fuel cut.
CONSULT-II Reference Value in Data Monitor ModeABS00CDI
Specification data are reference values.
*: Accelerator pedal position sensor 2 signal is converted by ECM internally. Thus, it differs from ECM terminal voltage.
On Board Diagnosis LogicABS00CDJ
These self-diagnoses have the one trip detection logic.
NOTE:
If DTC P2122 or P2123 is displayed with DTC P1229, first perform the trouble diagnosis for DTC P1229.
Refer to EC-1156
.
FAIL-SAFE MODE
When the malfunction is detected, ECM enters fail-safe mode and the MIL lights up.
PBIB1741E
MONITOR ITEM CONDITION SPECIFICATION
ACCEL SEN1

Ignition switch: ON
(Engine stopped)Accelerator pedal: Fully released 0.5 - 1.0V
Accelerator pedal: Fully depressed 4.0 - 4.7V
ACCEL SEN2*

Ignition switch: ON
(Engine stopped)Accelerator pedal: Fully released 0.3 - 1.2V
Accelerator pedal: Fully depressed 3.9 - 4.8V
CLSD THL POS

Ignition switch: ON
(Engine stopped)Accelerator pedal: Fully released ON
Accelerator pedal: Slightly depressed OFF
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P2122
2122Accelerator pedal posi-
tion sensor 1 circuit low
inputAn excessively low voltage from the APP sen-
sor 1 is sent to ECM.

Harness or connectors
(APP sensor 1 circuit is open or
shorted.)

Accelerator pedal position sensor
(Accelerator pedal position sensor 1) P2123
2123Accelerator pedal posi-
tion sensor 1 circuit high
inputAn excessively high voltage from the APP sen-
sor 1 is sent to ECM.
Engine operating condition in fail-safe mode
The ECM controls the electric throttle control actuator in regulating the throttle opening in order for the idle position to be within +10
degrees.
The ECM regulates the opening speed of the throttle valve to be slower than the normal condition.
So, the acceleration will be poor.

DTC P2122, P2123 APP SENSOR
EC-1231
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Revision: 2004 November 2004 FX35/FX45
4. If NG, replace accelerator pedal assembly and go to next step.
5. Perform EC-698, "
Accelerator Pedal Released Position Learning" .
6. Perform EC-698, "
Throttle Valve Closed Position Learning" .
7. Perform EC-698, "
Idle Air Volume Learning" .
Removal and InstallationABS00CDO
ACCELERATOR PEDAL
Refer to ACC-3, "ACCELERATOR CONTROL SYSTEM" .

EC-1232
[VK45DE]
DTC P2127, P2128 APP SENSOR
Revision: 2004 November 2004 FX35/FX45
DTC P2127, P2128 APP SENSORPFP:18002
Component DescriptionABS00CDP
The accelerator pedal position sensor is installed on the upper end
of the accelerator pedal assembly. The sensor detects the accelera-
tor position and sends a signal to the ECM.
Accelerator pedal position sensor has two sensors. These sensors
are a kind of potentiometers which transform the accelerator pedal
position into output voltage, and emit the voltage signal to the ECM.
In addition, these sensors detect the opening and closing speed of
the accelerator pedal and feed the voltage signals to the ECM. The
ECM judges the current opening angle of the accelerator pedal from
these signals and controls the throttle control motor based on these
signals.
Idle position of the accelerator pedal is determined by the ECM
receiving the signal from the accelerator pedal position sensor. The ECM uses this signal for the engine oper-
ation such as fuel cut.
CONSULT-II Reference Value in Data Monitor ModeABS00CDQ
Specification data are reference values.
*: Accelerator pedal position sensor 2 signal is converted by ECM internally. Thus, it differs from ECM terminal voltage.
On Board Diagnosis LogicABS00CDR
These self-diagnoses have the one trip detection logic.
FAIL-SAFE MODE
When the malfunction is detected, ECM enters fail-safe mode and the MIL lights up.
PBIB1741E
MONITOR ITEM CONDITION SPECIFICATION
ACCEL SEN1

Ignition switch: ON
(Engine stopped)Accelerator pedal: Fully released 0.5 - 1.0V
Accelerator pedal: Fully depressed 4.0 - 4.7V
ACCEL SEN2*

Ignition switch: ON
(Engine stopped)Accelerator pedal: Fully released 0.3 - 1.2V
Accelerator pedal: Fully depressed 3.9 - 4.8V
CLSD THL POS

Ignition switch: ON
(Engine stopped)Accelerator pedal: Fully released ON
Accelerator pedal: Slightly depressed OFF
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P2127
2127Accelerator pedal posi-
tion sensor 2 circuit low
inputAn excessively low voltage from the APP sen-
sor 2 is sent to ECM.

Harness or connectors
(APP sensor 2 circuit is open or
shorted.)
(TP sensor circuit is shorted.)

Accelerator pedal position sensor
(Accelerator pedal position sensor 2)

Electric throttle control actuator
(TP sensor 1 and 2) P2128
2128Accelerator pedal posi-
tion sensor 2 circuit high
inputAn excessively high voltage from the APP sen-
sor 2 is sent to ECM.
Engine operating condition in fail-safe mode
The ECM controls the electric throttle control actuator in regulating the throttle opening in order for the idle position to be within +10
degrees.
The ECM regulates the opening speed of the throttle valve to be slower than the normal condition.
So, the acceleration will be poor.

EC-1236
[VK45DE]
DTC P2127, P2128 APP SENSOR
Revision: 2004 November 2004 FX35/FX45
2. CHECK APP SENSOR 2 POWER SUPPLY CIRCUIT-I
1. Disconnect accelerator pedal position (APP) sensor harness
connector.
2. Turn ignition switch ON.
3. Check voltage between APP sensor terminal 4 and ground with
CONSULT-II or tester.
OK or NG
OK >> GO TO 8.
NG >> GO TO 3.
3. CHECK APP SENSOR 2 POWER SUPPLY CIRCUIT-II
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check harness continuity between APP sensor terminal 4 and ECM terminal 91.
Refer to Wiring Diagram.
OK or NG
OK >> GO TO 5.
NG >> GO TO 4.
4. DETECT MALFUNCTIONING PART
Check the following.

Harness connectors E211, M41

Harness for open or short between ECM and accelerator pedal position sensor
>> Repair or replace open circuit.
5. CHECK APP SENSOR 2 POWER SUPPLY CIRCUIT-III
Check harness for short to power and short to ground, between the following terminals.
OK or NG
OK >> GO TO 6.
NG >> Repair short to ground or short to power in harness or connectors.
PBIB1548E
Voltage: Approximately 5V
PBIB0915E
Continuity should exist.
ECM terminal Sensor terminal Reference Wiring Diagram
91 APP sensor terminal 4EC-1234
47 Electric throttle control actuator terminal 1EC-850