Escape 4WD L4-2.5L Hybrid (2009)
High Pressure Safety Valve HVAC: Description and Operation
Air Conditioning
Dual-Function Pressure Switch (Hybrid Only)
The dual-function pressure switch is located on the receiver/drier and includes 2 separate sets of contacts that are opened at 2 different pressures.
The first set of contacts in the dual-function pressure switch is used to interrupt A/C compressor operation in the event of excessively high discharge
pressure in the high-pressure side of the refrigerant system. The PCM monitors the first set of contacts in the dual-function pressure switch in-series with
the low-charge protection switch. When the contacts are open, the PCM will disengage the A/C compressor clutch.
The second set of contacts in the dual-function pressure switch is used by the PCM to engage the high-speed cooling fan. When the A/C pressure rises
above a preset level, the second set of contacts will close and the high-speed cooling fan will be engaged.
The dual-function pressure switch is installed on a Schrader-type valve core fitting on the receiver/drier. It is not necessary to recover the refrigerant to
remove the dual-function pressure switch.
