Chart C-1E - Power Steering Pressure Switch

Power Steering Pressure Switch (PSPS) is normally open and circuit No. 901 (Green/Yellow wire) is approximately battery voltage. When power steering pump pressure increases, PSPS closes, causing voltage on circuit No. 901 (Green/Yellow wire) to fall to less than one volt.

ECM monitors voltage and increases idle speed when voltage decreases. If PSPS fails to close or open exists in circuit No. 901 (Green/Yellow wire), engine may stall when power steering pump pressure is high. If PSPS fails to open or short to ground exists in circuit No. 901 (Green/Yellow wire), idle speed may be affected and A/C relay will be de-energized.

1. Check Scan tester instructions on how switch state will be displayed.
2. This step checks for a short to ground in circuit No. 901 (Green/Yellow wire).
3. This step simulates a closed switch.

Fig 1: Chart C-1E Schematic - Power Steering Pressure Switch

Courtesy of ISUZU MOTOR CO.

Fig 2: Chart C-1E Flow Chart - Power Steering Pressure Switch

Courtesy of ISUZU MOTOR CO.