Prizm L4-108 1.8L DOHC VIN 8 MFI (1998)
Power Steering Pressure Switch: Description and Operation
POwer Steering Pressure (PSP) Switch Signal
Power Steering Pressure (PSP) Switch Signal
The power steering pressure (PSP) switch (1) is located in high pressure line, near the power steering pump (2). The PSP switch signals the powertrain
control module (PCM) when the vehicle is experiencing power steering assist. Turning the steering wheel causes increased power steering fluid pressure
that closes the PSP switch. The PCM uses the PSP switch signal to adjust the idle air control (IAC) valve. In response to the PSP switch input the IAC
valve increases the idle speed before the power steering load can cause an engine idle quality concern.
