Power Steering Pressure Switch: Testing and Inspection

OPERATION
- The power steering pressure switch converts presence/absence of power steering load into low/nigh voltage and inputs it to the engine control module, which then controls the idle air control motor based on this signal.
- The battery voltage in the engine control module is applied through a resistor to the power steering pressure switch. Steering operation causes the power steering oil pressure to increase, turning the switch on. As a result, continuity is produced between the battery voltage applied and ground. This causes the power steering pressure terminal voltage to go from high to low.





INSPECTION
Using Scan Tool





Checking Oil Pressure

HARNESS INSPECTION





Measure the power supply voltage.
- Connector: Disconnected
- Ignition switch: ON
Voltage (V): Battery positive voltage
OK: STOP
NG: Repair the harness. (A1 -54)





1. Disconnect the pressure hose from the oil pump, and then connect the special tools.
2. Bleed the air, and then turn the steering wheel several times while the vehicle is not moving so that the temperature of the fluid rises to approximately 50 - 60° C (122 - 140° F).
3. The engine should be idling.
4. Disconnect the connection of the connector for the oil pressure switch, and place an ohmmeter in position.
5. Gradually close the shut-off valve of the pressure gauge and increase the hydraulic pressure then check whether or not the hydraulic pressure that activates the switch is the standard value.

Standard value: 1.5 - 2.0 MPa (213 - 284 psi)

6. Gradually open the shut-off valve and reduce the hydraulic pressure; then check whether or not the hydraulic pressure that deactivates the switch is the standard value.

Standard value: 0.7 - 1.2 MPa (100 - 171 psi)

7. Remove the special tools, and then tighten the pressure hose to the specified torque.

Tightening torque: 24 Nm (17 ft. lbs.)

8. Bleed the system.