2007 INFINITI M35 power steering

EC-470
[VQ35DE]
DTC P0506 ISC SYSTEM
Revision: 2007 April2007 M35/M45
DTC P0506 ISC SYSTEMPFP:23781
DescriptionNBS0051T
NOTE:
If DTC P0506 is displayed with other DTC, first perform the trouble diagnosis for the other DTC.
The ECM controls the engine idle speed to a specified level through the fine adjustment of the air, which is let
into the intake manifold, by operating the electric throttle control actuator. The operating of the throttle valve is
varied to allow for optimum control of the engine idling speed. The crankshaft position sensor (POS) detects
the actual engine speed and sends a signal to the ECM.
The ECM controls the electric throttle control actuator so that the engine speed coincides with the target value
memorized in the ECM. The target engine speed is the lowest speed at which the engine can operate steadily.
The optimum value stored in the ECM is determined by taking into consideration various engine conditions,
such as during warming up, deceleration, and engine load (air conditioner, power steering and cooling fan
operation, etc.).
On Board Diagnosis LogicNBS0051U
DTC Confirmation ProcedureNBS0051V
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.

If the target idle speed is out of the specified value, perform EC-86, "Idle Air Volume Learning" ,
before conducting DTC Confirmation Procedure. For the target idle speed, refer to the EC-716,
"SERVICE DATA AND SPECIFICATIONS (SDS)" .
TESTING CONDITION:

Before performing the following procedure, confirm that battery voltage is more than 11V at idle.

Always perform the test at a temperature above −10°C (14°F).
WITH CONSULT-II
1. Open engine hood.
2. Start engine and warm it up to normal operating temperature.
3. Turn ignition switch OFF and wait at least 10 seconds.
4. Turn ignition switch ON again and select “DATA MONITOR”
mode with CONSULT-II.
5. Start engine and run it for at least 1 minute at idle speed.
6. If 1st trip DTC is detected, go to EC-471, "
Diagnostic Procedure"
.
WITH GST
Follow the procedure “WITH CONSULT-II” above.
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0506
0506Idle speed control sys-
tem RPM lower than
expectedThe idle speed is less than the target idle
speed by 100 rpm or more.

Electric throttle control actuator

Intake air leak
SEF174Y

EC-472
[VQ35DE]
DTC P0507 ISC SYSTEM
Revision: 2007 April2007 M35/M45
DTC P0507 ISC SYSTEMPFP:23781
DescriptionNBS0051X
NOTE:
If DTC P0507 is displayed with other DTC, first perform the trouble diagnosis for the other DTC.
The ECM controls the engine idle speed to a specified level through the fine adjustment of the air, which is let
into the intake manifold, by operating the electric throttle control actuator. The operating of the throttle valve is
varied to allow for optimum control of the engine idling speed. The crankshaft position sensor (POS) detects
the actual engine speed and sends a signal to the ECM.
The ECM controls the electric throttle control actuator so that the engine speed coincides with the target value
memorized in the ECM. The target engine speed is the lowest speed at which the engine can operate steadily.
The optimum value stored in the ECM is determined by taking into consideration various engine conditions,
such as during warming up, deceleration, and engine load (air conditioner, power steering and cooling fan
operation, etc.).
On Board Diagnosis LogicNBS0051Y
DTC Confirmation ProcedureNBS0051Z
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.

If the target idle speed is out of the specified value, perform EC-86, "Idle Air Volume Learning" ,
before conducting DTC Confirmation Procedure. For the target idle speed, refer to the EC-716,
"SERVICE DATA AND SPECIFICATIONS (SDS)" .
TESTING CONDITION:

Before performing the following procedure, confirm that battery voltage is more than 11V at idle.

Always perform the test at a temperature above −10°C (14°F).
WITH CONSULT-II
1. Open engine hood.
2. Start engine and warm it up to normal operating temperature.
3. Turn ignition switch OFF and wait at least 10 seconds.
4. Turn ignition switch ON again and select “DATA MONITOR”
mode with CONSULT-II.
5. Start engine and run it for at least 1 minute at idle speed.
6. If 1st trip DTC is detected, go to EC-473, "
Diagnostic Procedure"
.
WITH GST
Follow the procedure “WITH CONSULT-II” above.
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0507
0507Idle speed control sys-
tem RPM higher than
expectedThe idle speed is more than the target idle
speed by 200 rpm or more.

Electric throttle control actuator

Intake air leak

PCV system
SEF174Y

EC-474
[VQ35DE]
DTC P0550 PSP SENSOR
Revision: 2007 April2007 M35/M45
DTC P0550 PSP SENSORPFP:49763
Component DescriptionNBS00521
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 ModeNBS00522
Specification data are reference values.
On Board Diagnosis LogicNBS00523
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-486, "
DTC P0643 SENSOR POWER SUPPLY" .
DTC Confirmation ProcedureNBS00524
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-476, "
Diagnostic Procedure"
.
WITH GST
Follow the procedure “WITH CONSULT-II” above.
PBIB1579E
MONITOR ITEM CONDITION SPECIFICATION
PW/ST SIGNAL

Engine: After warming up, idle
the engineSteering wheel: Not being turned OFF
Steering wheel: Being turned ON
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0550
0550Power steering pres-
sure sensor circuitAn 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

EC-476
[VQ35DE]
DTC P0550 PSP SENSOR
Revision: 2007 April2007 M35/M45
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 ProcedureNBS00526
1. CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten two ground screws on the body.
Refer to EC-160, "
Ground Inspection" .
OK or NG
OK >> GO TO 2.
NG >> Repair or replace ground connections.
TER-
MINAL
NO.WIRE
COLORITEM CONDITION DATA (DC Voltage)
12 R/GPower steering pressure
sensor[Engine is running]

Steering wheel: Being turned0.5 - 4.5V
[Engine is running]

Steering wheel: Not being turned0.4 - 0.8V
67 B/W Sensor ground[Engine is running]

Warm-up condition

Idle speedApproximately 0V
68 L/YSensor power supply
(Power steering pressure
sensor)[Ignition switch: ON]Approximately 5V
1. Body ground M70 2. Body ground M16
PBIB2782E

DTC P0550 PSP SENSOR
EC-477
[VQ35DE]
C
D
E
F
G
H
I
J
K
L
MA
EC
Revision: 2007 April2007 M35/M45
2. CHECK PSP SENSOR POWER SUPPLY CIRCUIT
1. Disconnect power steering pressure (PSP) sensor harness con-
nector.
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 3.
NG >> Repair open circuit or short to ground or short to power
in harness or connectors.
3. 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 4.
NG >> Repair open circuit or short to ground short to power in harness or connectors.
4. 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 5.
NG >> Repair open circuit or short to ground or short to power in harness or connectors.
5. CHECK PSP SENSOR
Refer to EC-478, "
Component Inspection" .
OK or NG
OK >> GO TO 6.
NG >> Replace PSP sensor.
PBIB1579E
Voltage: Approximately 5V
PBIB0188E
Continuity should exist.
Continuity should exist.

EC-478
[VQ35DE]
DTC P0550 PSP SENSOR
Revision: 2007 April2007 M35/M45
6. CHECK INTERMITTENT INCIDENT
Refer to EC-153, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
>>INSPECTION END
Component InspectionNBS00527
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 InstallationNBS00528
POWER STEERING PRESSURE SENSOR
Refer to PS-39, "HYDRAULIC LINE" .
Condition Voltage
Steering wheel: Being turned. 0.5 - 4.5V
Steering wheel: Not being turned. 0.4 - 0.8V
MBIB0126E

EC-486
[VQ35DE]
DTC P0643 SENSOR POWER SUPPLY
Revision: 2007 April2007 M35/M45
DTC P0643 SENSOR POWER SUPPLYPFP:18919
On Board Diagnosis LogicNBS0052I
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 ProcedureNBS0052J
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-489, "
Diagnostic Procedure" .
WITH GST
Follow the procedure “WITH CONSULT-II” above.
DTC No.Trouble diagnosis
nameDTC detecting condition Possible cause
P0643
0643Sensor power supply
circuit shortECM 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.)
(Battery current sensor circuit is shorted.)

Accelerator pedal position sensor

EVAP control system pressure sensor

Refrigerant pressure sensor

Power steering pressure sensor

Battery current 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) by the return
spring.
SEF058Y

EC-488
[VQ35DE]
DTC P0643 SENSOR POWER SUPPLY
Revision: 2007 April2007 M35/M45
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
COLORITEM CONDITION DATA (DC Voltage)
48 BRSensor power supply
(EVAP control system pres-
sure sensor)[Ignition switch: ON]Approximately 5V
49 B/YSensor power supply
(Refrigerant pressure sen-
sor, Battery current sensor)[Ignition switch: ON]Approximately 5V
68 L/YSensor power supply
(Power steering pressure
sensor)[Ignition switch: ON]Approximately 5V
82 WSensor ground
(APP sensor 1)[Engine is running]

Warm-up condition

Idle speedApproximately 0V
83 PSensor ground
(APP sensor 2)[Engine is running]

Warm-up condition

Idle speedApproximately 0V
90 LSensor power supply
(APP sensor 1)[Ignition switch: ON]Approximately 5V
91 BRSensor power supply
(APP sensor 2)[Ignition switch: ON]Approximately 5V
98 RAccelerator pedal position
sensor 2[Ignition switch: ON]

Engine stopped

Accelerator pedal: Fully released0.20 - 0.55V
[Ignition switch: ON]

Engine stopped

Accelerator pedal: Fully depressed1.85 - 2.40V
106 LGAccelerator pedal position
sensor 1[Ignition switch: ON]

Engine stopped

Accelerator pedal: Fully released0.4 - 1.1V
[Ignition switch: ON]

Engine stopped

Accelerator pedal: Fully depressed3.7 - 4.8V