2007 INFINITI FX35 power steering

DTC P0550 PSP SENSOR EC-1139
[VK45DE]
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Revision: 2006 July 2007 FX35/FX45
DTC P0550 PSP SENSORPFP:49763
Component DescriptionNBS0049W
Power steering pressure (PSP) sensor is installed to the power
steering high-pressure tube and detects a power steering load. This
sensor is a potentiometer which transforms the power steering load
into output voltage, and emits the voltage signal to the ECM. The
ECM controls the electric throttle control actuator and adjusts the
throttle valve opening angle to increase the engine speed and
adjusts the idle speed for the increased load.
CONSULT-II Reference Value in Data Monitor ModeNBS0049X
Specification data are reference values.
On Board Diagnosis LogicNBS0049Y
The MIL will not light up for this diagnosis.
NOTE:
If DTC P0550 is displayed with DTC P0643, first perform the trouble diagnosis for DTC P0643. Refer to
EC-1151, "
DTC P0643 SENSOR POWER SUPPLY" .
DTC Confirmation ProcedureNBS0049Z
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 and let it idle for at least 5 seconds.
4. If 1st trip DTC is detected, go to EC-1141, "
Diagnostic Proce-
dure" .
WITH GST
Follow the procedure “WITH CONSULT-II” above.
PBIB1484E
MONITOR ITEM CONDITION SPECIFICATION
PW/ST SIGNAL

Engine: After warming up, idle
the engine Steering wheel: Not being turned OFF
Steering wheel: Being turned ON
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0550
0550 Power steering pres-
sure sensor circuit An excessively low or high voltage from the
sensor is sent to ECM.

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

Power steering pressure sensor
SEF058Y

DTC P0550 PSP SENSOR EC-1141
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Revision: 2006 July 2007 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 ProcedureNBS004A1
1. CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten three ground screws on the body. Refer to EC-819, "
Ground Inspection" .
OK or NG
OK >> GO TO 2.
NG >> Repair or replace ground connections.
TER-
MINAL NO. WIRE
COLOR ITEM CONDITION DATA (DC Voltage)
12 R/G Power steering pressure
sensor [Engine is running]

Steering wheel: Being turned
0.5 - 4.5V
[Engine is running]

Steering wheel: Not being turned 0.4 - 0.8V
67 B/W Sensor ground [Engine is running]

Warm-up condition

Idle speed Approximately 0V
68 SB Sensor power supply
(Power steering pressure
sensor) [Ignition switch: ON]
Approximately 5V
PBIB2195E

EC-1142
[VK45DE]
DTC P0550 PSP SENSOR
Revision: 2006 July 2007 FX35/FX45
2. CHECK PSP SENSOR POWER SUPPLY CIRCUIT
1. Disconnect PSP sensor harness connector.
2. Turn ignition switch ON.
3. Check voltage between PSP sensor terminal 1 and ground with CONSULT-II or tester.
OK or NG
OK >> GO TO 4.
NG >> GO TO 3.
3. DETECT MALFUNCTIONING PART
Check the following.

Harness connectors E306, F46

Harness for open or short between power steering pressure sensor and ECM
>> Repair open circuit or short to ground or short to power in harness or connectors.
4. CHECK PSP SENSOR GROUND CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check harness continuity between PSP sensor terminal 3 and ECM terminal 67. Refer to Wiring Diagram.
4. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 6.
NG >> GO TO 5.
5. DETECT MALFUNCTIONING PART
Check the following.

Harness connectors E306, F46

Harness for open or short between power steering pressure sensor and ECM
>> Repair open circuit or short to ground short to power in harness or connectors.
PBIB1484E
Voltage: Approximately 5V
PBIB0188E
Continuity should exist.

DTC P0550 PSP SENSOR EC-1143
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Revision: 2006 July 2007 FX35/FX45
6. CHECK PSP SENSOR INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
1. Check harness continuity between ECM terminal 12 and PSP sensor terminal 2. Refer to Wiring Diagram.
2. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 8.
NG >> GO TO 7.
7. DETECT MALFUNCTIONING PART
Check the following.

Harness connectors E306, F46

Harness for open or short between power steering pressure sensor and ECM
>> Repair open circuit or short to ground or short to power in harness or connectors.
8. CHECK PSP SENSOR
Refer to EC-1143, "
Component Inspection" .
OK or NG
OK >> GO TO 9.
NG >> Replace PSP sensor.
9. CHECK INTERMITTENT INCIDENT
Refer to EC-812, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
>> INSPECTION END
Component InspectionNBS004A2
POWER STEERING PRESSURE SENSOR
1. Reconnect all harness connectors disconnected.
2. Start engine and let it idle.
3. Check voltage between ECM terminal 12 and ground under the following conditions.
Removal and InstallationNBS004A3
POWER STEERING PRESSURE SENSOR
Refer to PS-41, "HYDRAULIC LINE" .
Continuity should exist.
Condition Voltage
Steering wheel: Being turned 0.5 - 4.5V
Steering wheel: Not being turned 0.4 - 0.8V
MBIB0126E

DTC P0643 SENSOR POWER SUPPLY EC-1151
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Revision: 2006 July 2007 FX35/FX45
DTC P0643 SENSOR POWER SUPPLYPFP:18919
On Board Diagnosis LogicNBS004DA
This self-diagnosis has the one trip detection logic.
FAIL-SAFE MODE
When the malfunction is detected, ECM enters fail-safe mode and the MIL lights up.
DTC Confirmation ProcedureNBS004DB
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:
Before performing the following procedure, confirm that battery voltage is more than 10V at idle.
WITH CONSULT-II
1. Turn ignition switch ON.
2. Select “DATA MONITOR” mode with CONSULT-II.
3. Start engine and let it idle for 1 second.
4. If DTC is detected, go to EC-1154, "
Diagnostic Procedure" .
WITH GST
Follow the procedure “WITH CONSULT-II” above.
DTC No. Trouble diagnosis
name DTC detecting condition Possible cause
P0643
0643 Sensor power supply
circuit short ECM detects a voltage of power source for
sensor is excessively low or high.

Harness or connectors
(APP sensor 1 circuit is shorted.)
(EVAP control system pressure sensor is
shorted.)
(Refrigerant pressure sensor circuit is
shorted.)
(PSP sensor circuit is shorted.)

Accelerator pedal position sensor

EVAP control system pressure sensor

Refrigerant pressure sensor

Power steering pressure sensor
Engine operation condition in fail-safe mode
ECM stops the electric throttle control actuator control, throttle valve is maintained at a fixed opening (approx. 5 degrees) b y the return
spring.
SEF058Y

DTC P0643 SENSOR POWER SUPPLY EC-1153
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Revision: 2006 July 2007 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.
TER-
MINAL NO. WIRE
COLOR ITEM CONDITION DATA (DC Voltage)
48 L Sensor power supply
(EVAP control system pres-
sure sensor) [Ignition switch: ON]
Approximately 5V
49 PU Sensor power supply
(Refrigerant pressure sen-
sor) [Ignition switch: ON]
Approximately 5V
68 SB Sensor power supply
(Power steering pressure
sensor) [Ignition switch: ON]
Approximately 5V
82 B/W Sensor ground
(APP sensor 1 / ICC steer-
ing switch / ASCD steering
switch) [Engine is running]

Warm-up condition

Idle speed
Approximately 0V
83 G/OR Sensor ground
(APP sensor 2) [Engine is running]

Warm-up condition

Idle speed
Approximately 0V
90 L/B Sensor power supply
(APP sensor 1) [Ignition switch: ON]
Approximately 5V
91 G Sensor power supply
(APP sensor 2) [Ignition switch: ON]
Approximately 5V
98 Y/R Accelerator pedal position
sensor 2 [Ignition switch: ON]

Engine stopped

Accelerator pedal: Fully released
0.15 - 0.60V
[Ignition switch: ON]

Engine stopped

Accelerator pedal: Fully depressed 1.95 - 2.40V
106 OR Accelerator pedal position
sensor 1 [Ignition switch: ON]

Engine stopped

Accelerator pedal: Fully released
0.5 - 1.0V
[Ignition switch: ON]

Engine stopped

Accelerator pedal: Fully depressed 3.9 - 4.7V

DTC P0643 SENSOR POWER SUPPLY EC-1155
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Revision: 2006 July 2007 FX35/FX45
3. CHECK SENSOR POWER SUPPLY CIRCUITS
Check harness for short to power and short to ground, between the following terminals.
OK or NG
OK >> GO TO 4.
NG >> Repair short to ground or short to power in harness or connectors.
4. CHECK COMPONENTS
Check the following.

EVAP control system pressure sensor (Refer to EC-1101, "Component Inspection" .)

Refrigerant pressure sensor (Refer to AT C - 8 9 , "COMPONENT INSPECTION" .)

Power steering pressure sensor (Refer to EC-1143, "Component Inspection" .)
OK or NG
OK >> GO TO 7.
NG >> Replace malfunctioning component.
5. CHECK APP SENSOR
Refer to EC-1263, "
Component Inspection" .
OK or NG
OK >> GO TO 7.
NG >> GO TO 6.
6. REPLACE ACCELERATOR PEDAL ASSEMBLY
1. Replace accelerator pedal assembly.
2. Perform EC-745, "
Accelerator Pedal Released Position Learning" .
3. Perform EC-745, "
Throttle Valve Closed Position Learning" .
4. Perform EC-745, "
Idle Air Volume Learning" .
>> INSPECTION END
7. CHECK INTERMITTENT INCIDENT
Refer to EC-812, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
>> INSPECTION END
ECM terminal Sensor terminal Reference Wiring Diagram
90 APP sensor terminal 6 EC-1152
48 EVAP control system pressure sensor terminal 3EC-1098
49 Refrigerant pressure sensor terminal 1EC-1346
68 PSP sensor terminal 1 EC-1140

EC-1196
[VK45DE]
DTC P1564 ICC STEERING SWITCH
Revision: 2006 July 2007 FX35/FX45
3. CHECK ICC STEERING SWITCH GROUND CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Disconnect combination switch harness connector M203.
4. Check harness continuity between combination switch terminal 15 and ECM terminal 82. Refer to Wiring Diagram.
5. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 5.
NG >> GO TO 4.
4. DETECT MALFUNCTIONING PART
Check the following.

Combination switch (spiral cable)

Harness for open and short between ECM and combination switch
>> Repair open circuit or short to ground or short to power in harness or connectors.
5. CHECK ICC STEERING SWITCH INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
1. Check harness continuity between ECM terminal 99 and combination switch terminal 14. Refer to Wiring Diagram.
2. 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.

Combination switch (spiral cable)

Harness for open and short between ECM and combination switch
>> Repair open circuit or short to ground or short to power in harness or connectors.
7. CHECK ICC STEERING SWITCH
Refer to EC-1197, "
Component Inspection" .
OK or NG
OK >> GO TO 8.
NG >> Replace ICC steering switch.
8. CHECK INTERMITTENT INCIDENT
Refer to EC-812, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
>> INSPECTION END
Continuity should exist.
Continuity should exist.