Nissan Altima 2007-2012 Service Manual: P0550 PSP Sensor

Description

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

DTC DETECTION LOGIC

NOTE: If DTC P0550 is displayed with DTC P0643, first perform the trouble diagnosis for DTC P0643. Refer to EC-867, "DTC Logic".

DTC CONFIRMATION PROCEDURE

1.PRECONDITIONING

If DTC Confirmation Procedure has been previously conducted, always turn ignition switch OFF and wait at least 10 seconds before conducting the next test.

>> 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-859, "Diagnosis Procedure".

NO >> INSPECTION END

Diagnosis Procedure

1.CHECK GROUND CONNECTION

1. Turn ignition switch OFF.

2. Check ground connection E9. Refer to Ground Inspection in GI-45, "Circuit Inspection".

Is the inspection result normal? YES >> GO TO 2.

NO >> Repair or replace ground connection.

2.CHECK PSP SENSOR POWER SUPPLY CIRCUIT

1. Disconnect power steering pressure (PSP) sensor harness connector.

2. Turn ignition switch ON.

3. Check the voltage between PSP sensor harness connector and ground.

Is the inspection result normal? YES >> GO TO 3.

NO >> 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 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 or 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 or short to ground or short to power in harness or connectors.

5.CHECK PSP SENSOR

Refer to EC-860, "Component Inspection".

Is the inspection result normal? YES >> GO TO 6.

NO >> Replace PSP sensor.

6.CHECK INTERMITTENT INCIDENT

Refer to GI-42, "Intermittent Incident".

>> INSPECTION END

Component Inspection

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 and ground under the following conditions.

Is the inspection result normal? YES >> INSPECTION END

NO >> Replace power steering pressure sensor.

    P0507 ISC System
    Description 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 ac ...

    P0603 ECM Power supply
    Description 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, ...

    Other materials:

    P0132, P0152 A/F sensor 1
    Description The air fuel ratio (A/F) sensor 1 is a planar one-cell limit current sensor. The sensor element of the A/F sensor 1 is composed an electrode layer, which transports ions. It has a heater in the element. The sensor is capable of precise measurement = 1, but also in the lean and ...

    P0335 CKP Sensor (POS)
    Description The crankshaft position sensor (POS) is located on the oil pan facing the gear teeth (cogs) of the signal plate. It detects the fluctuation of the engine revolution. The sensor consists of a permanent magnet and Hall IC. When the engine is running, the high and low parts of the ...

    Mixture ratio self-learning value clear
    Description This describes how to erase the mixture ratio self-learning value. For the actual procedure, follow the instructions in “Diagnosis Procedure”. Special Repair Requirement 1.START 1. Start engine and warm it up to normal operating temperature. 2. Select “SELF-LEARNING CO ...