Humming noise from the power steering system

Procedure(s)

1. Check when the noise occurs:
2. If the noise is heard 2−3 minutes after starting the engine in cold weather, this is normal.
3. If the noise is heard when the wheel is turned with the vehicle stopped, this is normal due to the fluid pulsation.
4. Check for the high-pressure hose touching the subframe or body.
5. Check for automatic transmission converter noise.
6. Check for air bubbles in the power steering fluid, leak on inlet side of pump.
7. Check for particle contamination of fluid and restricted filter in the reservoir.

Also check for:

- Pump pressure