Possible causes

– Faulty Power Steering Pressure Sensor
– Power Steering Pressure Sensor harness is open or shorted
– Power Steering Pressure Sensor circuit poor electrical connection

When is the code detected?

An excessively low or high voltage from the sensor is sent to ECM.

Symptoms

– Engine Light ON (or Service Engine Soon Warning Light)
– Power steering inoperative

P0550 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 Engine Control Module (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.

P0550 Information for specific makes

P0550 INFINITI
P0550 MAZDA
P0550 NISSAN
P0550 TOYOTA
P0550 LEXUS