Power Steering Pressure Switch (Liberty & Wrangler)
On Liberty, Power Steering Pressure (PSP) switch is located in high-pressure line near rear of power steering pump. On Wrangler 2.5L, PSP switch is located in high-pressure line. See Fig 1 . On all models, the power steering pressure switch provides an input to the Powertrain Control Module (PCM). This input is provided during periods of high steering pump load and low engine RPM; such as during parking maneuvers. The PCM increases the idle speed through the Idle Air Control (IAC) motor. This is done to prevent the engine from stalling under the increased load. When steering pump pressure exceeds 375-575 psi (2586-3965 kPa), the Normally Closed (NC) switch will open and the PCM will increase the engine idle speed. This will prevent the engine from stalling. When pump pressure drops to approximately 200 psi (1379 kPa ), the switch circuit will re-close and engine idle speed will return to its previous setting.