Manuals through 2025 now available!

Our trusted friends have launched a new website named LEMON, which has newer manuals. It also contains all the CHARM manuals.

LEMON is the spiritual successor to CHARM, I recommend you try it!

Link: lemon-manuals.la or lemon-manuals.org.ua

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Power Steering Pressure Switch: Description and Operation

Pressure Switch
When hydraulic pressure reaches 3430 kPa (500 psi), the pressure switch closes causing the Engine Control Module (ECM) to actuate the idle air control valve, which increases the engine rpm to prevent the overload-induced engine speed slow down. The switch opens when hydraulic pressure drops to 2940 kPa (430 psi).