The Power Steering Pressure (PSP) switch (Figure 38) monitors the hydraulic pressure within the power steering system. The PSP switch is a normally closed switch that opens as the hydraulic pressure increases. The PCM uses the input signal from the PSP switch to compensate for additional loads on the engine by adjusting the idle rpm and preventing engine stall during parking maneuvers. Also, the PSP switch signals the PCM to adjust transmission Electronic Pressure Control (EPC) pressure during the increased engine load, for example during parking maneuvers.