C-1E ~ Power Steering Pressure Switch (PSP)

Chart C-1E Circuit Diagram:

Diagnostic Chart C-1E Power Steering Switch:

CIRCUIT DESCRIPTION:

The power steering pressure switch PSPS is normally open to ground, and CKT 901 wire will be near the battery voltage. Turning the steering wheel increases power steering oil pressure and its load on an idling engine. The pressure switch will close before the load can cause an idle problem. Closing the switch causes CKT 901 to read less than 1 volt. The ECM will increase the idle air rate and disengage the A/C relay. A pressure switch that will not close, or an open CKT 901, may cause the engine to stop, when power steering loads are high. A switch that will not open or a CKT 901 shorted to ground, may affect idle quality and will cause the A/C relay to be de-energized.

TEST DESCRIPTION: Numbers below refer to the circled numbers on the diagnostic chart.

1. Different makes of Scan tools may display the state of this switch in different ways.

2. Checks to determine if CKT 901 is shorted to ground.

3. This should simulate a closed switch.