Power Steering Pressure Switch
NOTE:
Only component testing procedure is covered. For Power Steering Pressure (PSP) switch system and circuit testing procedure, see appropriate SELF-DIAGNOSTICS article.
NOTE:
For PSP sensor removal and installation, see appropriate POWER STEERING PRESSURE SENSOR under ENGINE SENSORS & SWITCHES in REMOVAL, OVERHAUL & INSTALLATION article.
Power Steering Pressure (PSP) switch closes in response to an increase in power steering fluid pressure (load condition). With switch closed, a monitored voltage circuit supplied by ECM is pulled low to vehicle ground through switch. ECM then sends a signal to ISC actuator to adjust idle speed to compensate for increased engine load.
- Turn ignition off, disconnect power steering pressure switch 1-pin harness connector located on power steering pump. Using a DVOM, check for continuity between switch and chassis ground. See Fig 1. Start engine, continuity should not exist with wheels in straight-ahead position and engine idling. Continuity should exist when steering wheel is turned.
- Turn engine off. Turn ignition switch to ON position. Measure voltage between switch connector and ground. If battery voltage is present, circuit is okay. If battery voltage is not present, repair circuit between switch and ECM.