Jeep Wrangler/YJ 1987-1995 Repair Guide

Pressure Sensing Switch


A pressure sensing switch is included in the power steering system to increase the idle speed during periods of high pump load and low engine rpm. Input signals from the pressure switch to the ECU are routed through the A/C request and A/C select input circuits. When pump pressure exceeds 250-300 psi (1724-2068 kPa), the switch contacts close and transmit an input signal to the ECU. The ECU raises engine idle speed immediately after receiving the pressure switch input signal.