Infiniti FX35 / FX45. Manual - part 560

DTC P0550 PSP SENSOR

EC-1001

< SERVICE INFORMATION >

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3.

Check voltage between PSP sensor terminal 1 and ground with
CONSULT-III 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.

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-1002, "Component Inspection"

.

Voltage: Approximately 5V

PBIB0188E

Continuity should exist.

Continuity should exist.

EC-1002

< SERVICE INFORMATION >

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DTC P0550 PSP SENSOR

OK or NG

OK

>> GO TO 9.

NG

>> Replace PSP sensor.

9.

CHECK INTERMITTENT INCIDENT

Refer to 

EC-717

.

>> INSPECTION END

Component Inspection

INFOID:0000000001326857

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 Installation

INFOID:0000000001326858

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

DTC P0603 ECM POWER SUPPLY

EC-1003

< SERVICE INFORMATION >

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DTC P0603 ECM POWER SUPPLY

Component Description

INFOID:0000000001326859

Battery voltage is supplied to the ECM even when the ignition switch
is turned OFF for the ECM memory function of the DTC memory, the
air-fuel ratio feedback compensation value memory, the idle air vol-
ume learning value memory, etc.

On Board Diagnosis Logic

INFOID:0000000001326860

DTC Confirmation Procedure

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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.

1.

Turn ignition switch ON and wait at least 1 second.

2.

Start engine and let it idle for 1 second.

3.

Turn ignition switch OFF, wait at least 10 seconds, and then turn ON.

4.

Repeat steps 2 and 3 for four times.

5.

Check 1st trip DTC.

6.

If 1st trip DTC is detected, go to 

EC-1005, "Diagnosis Procedure"

.

PBIB1164E

DTC No.

Trouble diagnosis name

DTC detecting condition

Possible cause

P0603
0603

ECM power supply cir-
cuit

ECM back-up RAM system does not function 
properly.

• Harness or connectors

[ECM power supply (back-up) circuit is 
open or shorted.]

• ECM

EC-1004

< SERVICE INFORMATION >

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DTC P0603 ECM POWER SUPPLY

Wiring Diagram

INFOID:0000000001326862

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.

TBWM1341E