2008 INFINITI FX35 power steering

DTC P0550 PSP SENSOREC-413
< SERVICE INFORMATION > [VQ35DE]
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DTC P0550 PSP SENSOR
Component DescriptionINFOID:0000000001326254
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-III Reference Val ue in Data Monitor ModeINFOID:0000000001326255
Specification data are reference values.
On Board Diagnosis LogicINFOID:0000000001326256
The MIL will not light up for this self-diagnosis.
NOTE:
If DTC P0550 is displayed with DTC P0643, first perform the trouble diagnosis for DTC P0643.
Refer to EC-424
.
DTC Confirmation ProcedureINFOID:0000000001326257
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.
1. Start engine and let it idle for at least 5 seconds.
2. Check 1st trip DTC.
3. If 1st trip DTC is detected, go to EC-415, "
Diagnosis Procedure".
PBIB1579E
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 pressure
sensor circuit An excessively low or high voltage from the
sensor is sent to ECM.  Harness or connectors
(Power steering pressure sensor circuit is
open or shorted)
 Power steering pressure sensor
3AA93ABC3ACD3AC03ACA3AC03AC63AC53A913A773A893A873A873A8E3A773A983AC73AC93AC03AC3
3A893A873A873A8F3A773A9D3AAF3A8A3A8C3A863A9D3AAF3A8B3A8C

DTC P0550 PSP SENSOREC-415
< SERVICE INFORMATION > [VQ35DE]
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Diagnosis ProcedureINFOID:0000000001326259
1.CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten ground screw on the body. Refer to EC-144, "
Ground Inspection".
OK or NG
OK >> GO TO 2.
NG >> Repair or replace ground connections.
2.CHECK POWER STEERING PRESSURE (P SP) SENSOR POWER SUPPLY CIRCUIT
1. Disconnect power steering pressure (PSP) sensor harness con- nector.
2. Turn ignition switch ON.
TER-
MI-
NAL
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 BR Sensor power supply
(Power steering pressure
sensor) [Ignition switch: ON]
Approximately 5V
PBIB2625E
PBIB1579E
3AA93ABC3ACD3AC03ACA3AC03AC63AC53A913A773A893A873A873A8E3A773A983AC73AC93AC03AC3
3A893A873A873A8F3A773A9D3AAF3A8A3A8C3A863A9D3AAF3A8B3A8C

EC-416
< SERVICE INFORMATION >[VQ35DE]
DTC P0550 PSP SENSOR
3. Check voltage between PSP sensor terminal 1 and ground with
CONSULT-III or tester.
OK or NG
OK >> GO TO 3.
NG >> Repair open circuit or short to ground or short to power in harness or connectors.
3.CHECK POWER STEERING PRESSURE SENSO R 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 4.
NG >> Repair open circuit or short to ground or short to power in harness or connectors.
4.CHECK POWER STEERING PRESSURE SENSOR INPU T 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 5.
NG >> Repair open circuit or short to ground or short to power in harness or connectors.
5.CHECK POWER STEERING PRESSURE SENSOR
Refer to EC-416, "
Component Inspection".
OK or NG
OK >> GO TO 6.
NG >> Replace power steering pressure sensor.
6.CHECK INTERMITTENT INCIDENT
Refer to EC-139
.
>> INSPECTION END
Component InspectionINFOID:0000000001326260
POWER STEERING PRESSURE SENSOR
1. Reconnect all harness connectors disconnected.
2. Start engine and let it idle. Voltage: Approximately 5V
PBIB0188E
Continuity should exist.
Continuity should exist.
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3A893A873A873A8F3A773A9D3AAF3A8A3A8C3A863A9D3AAF3A8B3A8C

DTC P0550 PSP SENSOREC-417
< SERVICE INFORMATION > [VQ35DE]
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3. Check voltage between ECM terminal 12 and ground under the
following conditions.
Removal and InstallationINFOID:0000000001326261
POWER STEERING PRESSURE SENSOR
Refer to PS-37.
Condition Voltage
Steering wheel: Being turned 0.5 - 4.5V
Steering wheel: Not being turned 0.4 - 0.8V
MBIB0126E
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3A893A873A873A8F3A773A9D3AAF3A8A3A8C3A863A9D3AAF3A8B3A8C

EC-424
< SERVICE INFORMATION >[VQ35DE]
DTC P0643 SENSOR POWER SUPPLY
DTC P0643 SENSOR POWER SUPPLY
On Board Diagn
osis LogicINFOID:0000000001326271
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 ProcedureINFOID:0000000001326272
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.
TESTING CONDITION:
Before performing the following procedure, confirm that battery voltage is more than 8V at idle.
1. Start engine and let it idle for 1 second.
2. Check DTC.
3. If DTC is detected, go to EC-426, "
Diagnosis Procedure".
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.)
(PSP sensor circuit is shorted.)
(Refrigerant pressure sensor circuit is short-
ed.)
(EVAP control system pressure sensor circuit
is shorted.)
 Accelerator pedal position sensor (APP sensor 1)
 EVAP control system pressure sensor
 Power steering pressure sensor
 Refrigerant 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.
3AA93ABC3ACD3AC03ACA3AC03AC63AC53A913A773A893A873A873A8E3A773A983AC73AC93AC03AC3
3A893A873A873A8F3A773A9D3AAF3A8A3A8C3A863A9D3AAF3A8B3A8C

EC-426
< SERVICE INFORMATION >[VQ35DE]
DTC P0643 SENSOR POWER SUPPLY
Diagnosis Procedure
INFOID:0000000001326274
1.CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten ground screw on the body. Refer to EC-144, "
Ground Inspection".
OK or NG
OK >> GO TO 2.
NG >> Repair or replace ground connections.
2.CHECK ACCELERATOR PEDAL POSITION SENSOR 1 POWER SUPPLY CIRCUIT-I
TER-
MI-
NAL
NO. WIRE
COLOR ITEM CONDITION DATA (DC Voltage)
48 LG 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 BR Sensor power supply
(Power steering pressure
sensor) [Ignition switch: ON]
Approximately 5V
82 B/W Sensor ground
(APP sensor 1, ASCD steer-
ing switch, ICC 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
PBIB2625E
3AA93ABC3ACD3AC03ACA3AC03AC63AC53A913A773A893A873A873A8E3A773A983AC73AC93AC03AC3
3A893A873A873A8F3A773A9D3AAF3A8A3A8C3A863A9D3AAF3A8B3A8C

DTC P0643 SENSOR POWER SUPPLYEC-427
< SERVICE INFORMATION > [VQ35DE]
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1. Disconnect accelerator pedal position (APP) sensor harness
connector.
2. Turn ignition switch ON.
3. Check voltage between APP sensor terminal 6 and ground with
CONSULT-III or tester.
OK or NG
OK >> GO TO 5.
NG >> GO TO 3.
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 6.
NG >> Repair short to ground or short to power in harness or connectors.
4.CHECK COMPONENTS
Check the following.
 Refrigerant pressure sensor (Refer to ATC-69, "
Magnet Clutch Circuit".)
 Power steering pressure sensor (Refer to EC-416, "
Component Inspection".)
 EVAP control system pressure sensor (Refer to EC-373, "
Component Inspection".)
OK or NG
OK >> GO TO 7.
NG >> Replace malfunctioning component.
5.CHECK ACCELERATOR PEDAL POSITION SENSOR
Refer to EC-511, "
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-85, "
Accelerator Pedal Released Position Learning".
3. Perform EC-85, "
Throttle Valve Closed Position Learning".
4. Perform EC-85, "
Idle Air Volume Learning".
PBIB1580E
Voltage: Approximately 5V
PBIB0914E
ECM terminal Sensor terminal Reference Wiring Diagram
90 APP sensor terminal 6 EC-508
49 Refrigerant pressure sensor terminal 1EC-582
68 PSP sensor terminal 1EC-414
48 EVAP control system pressure sensor terminal 3EC-377
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3A893A873A873A8F3A773A9D3AAF3A8A3A8C3A863A9D3AAF3A8B3A8C

DTC P1564 ICC STEERING SWITCHEC-457
< SERVICE INFORMATION > [VQ35DE]
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1. Turn ignition switch ON.
2. Check voltage between ECM terminal 99 and ground with press- ing each button.
OK or NG
OK >> GO TO 8.
NG >> GO TO 3.
3.CHECK ICC STEERING SWITCH GRO UND CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch OFF.
2. Disconnect combination switch harness connector.
3. Disconnect ECM harness connector.
4. Check harness continuity between combinati on 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 SI GNAL 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.
DISTANCE switch DIST SW Pressed ON
Released OFF
Switch Monitor item Condition Indication
Switch Condition Voltage [V]
MAIN switch Pressed Approx. 0
Released Approx. 4.3
CANCEL switch Pressed Approx. 1.3
Released Approx. 4.3
RESUME/ACCELER-
ATE switch Pressed Approx. 3.7
Released Approx. 4.3
SET/COAST switch Pressed Approx. 3.0
Released Approx. 4.3
DISTANCE switch Pressed Approx. 2.2
Released Approx. 4.3
PBIB0311E
Continuity should exist.
Continuity should exist.
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