Infiniti FX35, FX50 (S51). Manual - part 702

 

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Infiniti FX35, FX50 (S51). Manual - part 702

 

 

P0507 ISC SYSTEM

EC-349

< DTC/CIRCUIT DIAGNOSIS >

[VQ35HR]

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P0507 ISC SYSTEM

Description

INFOID:0000000005236934

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 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.). 

DTC Logic

INFOID:0000000005236935

DTC DETECTION LOGIC

NOTE:
If DTC P0507 is displayed with other DTC, first perform the trouble diagnosis for the other DTC.

DTC CONFIRMATION PROCEDURE

1.

PRECONDITIONING

If DTC Confirmation Procedure has been previously conducted, always perform the following procedure
before conducting the next test.
1.

Turn ignition switch OFF and wait at least 10 seconds.

2.

Turn ignition switch ON.

3.

Turn ignition switch OFF and wait at least 10 seconds.

If the target idle speed is out of the specified value, perform 

EC-25, "IDLE AIR VOLUME LEARNING :

Special Repair Requirement"

, before conducting DTC Confirmation Procedure.

TESTING CONDITION:
• Before performing the following procedure, confirm that battery voltage is more than 11 V at idle.
• Always perform the test at a temperature above 

10

°

C(14

°

F).

>> GO TO 2.

2.

PERFORM DTC CONFIRMATION PROCEDURE

1.

Start engine and warm it up to normal operating temperature.

2.

Turn ignition switch OFF and wait at least 10 seconds.

3.

Turn ignition switch ON.

4.

Turn ignition switch OFF and wait at least 10 seconds.

5.

Start engine and run it for at least 1 minute at idle speed.

6.

Check 1st trip DTC.

Is 1st trip DTC detected?

YES

>> Go to 

EC-349, "Diagnosis Procedure"

.

NO

>> INSPECTION END

Diagnosis Procedure

INFOID:0000000005236936

1.

CHECK PCV HOSE CONNECTION

Confirm that PCV hose is connected correctly.

Is the inspection result normal?

YES

>> GO TO 2.

DTC No.

Trouble diagnosis name

DTC detecting condition

Possible cause

P0507

Idle speed control sys-
tem RPM higher than 
expected

The idle speed is more than the target idle 
speed by 200 rpm or more.

• Electric throttle control actuator
• Intake air leak
• PCV system

EC-350

< DTC/CIRCUIT DIAGNOSIS >

[VQ35HR]

P0507 ISC SYSTEM

NO

>> Repair or replace malfunctioning part.

2.

CHECK INTAKE AIR LEAK

1.

Start engine and let it idle.

2.

Listen for an intake air leak after the mass air flow sensor.

Is intake air leak detected?

YES

>> Discover air leak location and repair.

NO

>> GO TO 3.

3.

REPLACE ECM

1.

Stop engine.

2.

Replace ECM.

3.

Go to 

EC-23, "ADDITIONAL SERVICE WHEN REPLACING CONTROL UNIT : Special Repair Require-

ment"

.

>> INSPECTION END

P0550 PSP SENSOR

EC-351

< DTC/CIRCUIT DIAGNOSIS >

[VQ35HR]

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P0550 PSP SENSOR

Description

INFOID:0000000005236937

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.

DTC Logic

INFOID:0000000005236938

DTC DETECTION LOGIC

NOTE:
If DTC P0550 is displayed with DTC P0643, first perform the trouble diagnosis for DTC P0643. Refer to

EC-359, "DTC Logic"

.

DTC CONFIRMATION PROCEDURE

1.

PRECONDITIONING

If DTC Confirmation Procedure has been previously conducted, always perform the following procedure
before conducting the next test.
1.

Turn ignition switch OFF and wait at least 10 seconds.

2.

Turn ignition switch ON.

3.

Turn ignition switch OFF and wait at least 10 seconds.

>> GO TO 2.

2.

PERFORM DTC CONFIRMATION PROCEDURE

1.

Start engine and let it idle for at least 5 seconds.

2.

Check 1st trip DTC.

Is 1st trip DTC detected?

YES

>> Go to 

EC-351, "Diagnosis Procedure"

.

NO

>> INSPECTION END

Diagnosis Procedure

INFOID:0000000005236939

1.

CHECK GROUND CONNECTION

1.

Turn ignition switch OFF.

2.

Check ground connection M95. Refer to Ground Inspection in 

GI-39, "Circuit Inspection"

.

Is the inspection result normal?

YES

>> GO TO 2.

NO

>> Repair or replace ground connection.

2.

CHECK POWER STEERING PRESSURE (PSP) SENSOR POWER SUPPLY CIRCUIT

1.

Disconnect PSP sensor harness connector.

2.

Turn ignition switch ON.

3.

Check the voltage between PSP sensor harness connector and ground.

DTC No.

Trouble diagnosis name

DTC detecting condition

Possible cause

P0550

Power steering pressure 
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

PSP sensor

Ground

Voltage (V)

Connector

Terminal

F35

3

Ground

Approx. 5

EC-352

< DTC/CIRCUIT DIAGNOSIS >

[VQ35HR]

P0550 PSP SENSOR

Is the inspection result normal?

YES

>> GO TO 3.

NO

>> Repair open circuit, 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 the continuity between PSP sensor harness connector and ECM harness connector.

4.

Also check harness for short to ground and short to power.

Is the inspection result normal?

YES

>> GO TO 4.

NO

>> Repair open circuit, short to ground short to power in harness or connectors.

4.

CHECK PSP SENSOR INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT

1.

Check the continuity between PSP sensor harness connector and ECM harness connector.

2.

Also check harness for short to ground and short to power.

Is the inspection result normal?

YES

>> GO TO 5.

NO

>> Repair open circuit, short to ground or short to power in harness or connectors.

5.

CHECK PSP SENSOR

Refer to 

EC-352, "Component Inspection"

.

Is the inspection result normal?

YES

>> GO TO 6.

NO

>> Replace PSP sensor.

6.

CHECK INTERMITTENT INCIDENT

Refer to 

GI-36, "Intermittent Incident"

.

>> INSPECTION END

Component Inspection

INFOID:0000000005236940

1.

CHECK POWER STEERING PRESSURE SENSOR

1.

Turn ignition switch OFF.

2.

Reconnect all harness connectors disconnected.

3.

Start engine and let it idle.

4.

Check the voltage between ECM harness connector terminals under the following conditions.

Is the inspection result normal?

PSP sensor

ECM

Continuity

Connector

Terminal

Connector

Terminal

F35

1

F102

96

Existed

PSP sensor

ECM

Continuity

Connector

Terminal

Connector

Terminal

F35

2

F102

87

Existed

ECM

Condition

Voltage (V)

Connector

+

Terminal

Terminal

F102

87

96

Steering wheel

Being turned

0.5 - 4.5

Not being turned

0.4 - 0.8

 

 

 

 

 

 

 

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