Genuine Lexus ES350 Power Steering Pressure Switch

Lexus ES350 Power Steering Pressure Switch Parts Questions & Experts Answers

• Switch, Power Steering Oil Pressure
  89438-33010
  Q: How to check and replace the power steering pressure switch on Lexus ES350?

  A:

  The power steering pressure (PSP) switch is located at the high pressure line outlet fitting of the Power Steering Pump. When steering system pressure reaches a high-pressure set point, the PSP switch closes and sends a signal to the PCM that the PCM uses to maintain engine idle speed during parking maneuvers. Check the operation of the PSP switch if the engine stalls during parking or if the engine idles continuously at high rpm. Loosen the right front wheel lug nuts, raise the vehicle and support it securely on jackstands. Remove the right front wheel and the right front fender apron seal. Disconnect the PSP switch connector and connect an ohmmeter to the terminal and the switch body. Start the engine and let it idle. Turn the steering wheel to point the front wheels straight ahead and read the ohmmeter. It should indicate no continuity (infinite resistance). Turn the steering wheel to each side and watch the ohmmeter. The PSP switch should close as the wheel nears the steering stop on each side, and the meter should indicate continuity (zero ohms). If the switch fails either test, replace it. To replace, raise the vehicle and support it securely on jackstands. Disconnect the cable from the negative battery terminal. Disconnect the electrical connector from the switch and unscrew the switch from the fitting on the steering pump. Remove the old O-ring on the switch and install a new O-ring. Install and connect the new switch and lower the vehicle to the ground. Bleed air from the power steering system. Add fluid as required.