Table C-1C Power Steering Pressure (PSP) Switch Check

Power Steering Pressure (PSP) Switch Check:

Power Steering Pressure (PSP) Switch Check:

Circuit Description

The Power Steering Pressure (PSP) switch is normally open to ground, and the Powertrain Control Module (PCM) terminal will be near battery voltage.

Turning the steering wheel increases power steering oil pressure and its load on an idling engine. The PSP switch will close before the load can cause a poor idling condition.

Closing the switch causes the PCM voltage signal to read less than one volt. The PCM will increase the idle speed and prevent engine load stall.

Diagnostic Aids

An intermittent malfunction, may be caused by a poor connection, rubbed through wire insulation, or a wire broken inside the insulation. Check for the following items:

^ Inspect harness connectors for backed out terminals, improper mating, broken locks, improperly formed or damaged terminals and poor terminal-to-wire connections before component replacement.

^ A PSP switch that will not close, or loss of ground at the PSP switch may cause the engine to stall when power steering loads are high.

^ A PSP switch that will not open or a signal line shorted to ground may affect Idle quality.

Test Description

Number(s) below refer to the step number(s) on the Diagnostic Table.

1. The Powertrain OBD System Check prompts the technician to complete some basic checks and store the freeze frame data on the scan tool if applicable. This creates an electronic copy of the data taken when the fault occurred. The information is then stored in the scan tool for later reference.

3. Checks for PCM signal voltage and for an open or a short to ground in signal circuit or for a faulty PCM.

4. Checks for a poor ground connection at the power steering pump and for a faulty PSP switch.