RAM 2500 Truck 4WD L6-6.7L DSL Turbo VIN A (2007)
Power Steering Pressure Switch: Description and Operation
Operation
OPERATION
The switch is used on the 5.7L V-8 engines HD vehicles only.
The power steering pressure switch provides an input to the Powertrain Control Module (PCM). This input is provided during periods of high steering
pump load and low engine rpm; such as during parking maneuvers. The PCM increases the idle speed through the Idle Air Control (IAC) motor. This is
done to prevent the engine from stalling under the increased load.
When steering pump pressure exceeds 3275 kPa ± 690 kPa (475 psi ± 100 psi), the Normally Closed (NC) switch will open and the PCM will increase
the engine idle speed. This will prevent the engine from stalling.
When pump pressure drops to approximately 1379 kPa (200 psi), the switch circuit will re-close and engine idle speed will return to its previous setting.
