Power Steering Pressure Switch

The Power Steering Pressure (PSP) switch signals the PCM when power steering pressure exceeds a specified limit. PCM will adjust idle speed to compensate for added load on engine. The increase in RPM is used as an input to PCM to adjust EPC pressure to transaxle. If PSP switch fails on, EPC will be high, firm engagements and shifts, and harsh coastdown shifts may occur. If PSP switch fails off, EPC pressure will be lower during increased loading of the power steering system.