Sentra GXE L4-1.8L (QG18DE) (2000)
Part 2 Of 2
PERFORMANCE TEST DIAGNOSES
PERFORMANCE CHART
The Nissan A/C system uses a thermal expansion valve to provide a restriction which causes a pressure change and also controls refrigerant flow through
the evaporator.
The best way to diagnose a condition in the refrigerant system is to note the system pressures (shown by the manifold gauges) and the clutch cycle rate
and times.
Then, compare the findings to the charts.
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The system pressures are low (compressor suction) and high (compressor discharge).
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A clutch cycle is the time the clutch is engaged plus the time it is disengaged (time on plus time off).
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Clutch cycle times are the lengths of time (in seconds) that the clutch is ON and OFF.