Power Steering Pressure Switch: Testing and Inspection

POWER STEERING PRESSURE SWITCH

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




INSPECTION

Using Scan Tool





Checking Fluid Pressure

HARNESS INSPECTION





STEP 1. Check for an open or short-circuit between the power steering pressure switch and the engine control module.
- Power steering pressure switch connector: Disconnected
- Engine control module connector: Disconnected

OK: GO TO STEP 2
NG: Repair the harness. (A1 - 37)





STEP 2. Measure the applied voltage.
- Power steering pressure switch connector: Disconnected
- Engine control module connector: Connected
- Ignition switch: ON

Voltage (V): Battery positive voltage

OK: STOP
NG: Replace the engine control module.