Test Description

WARNING: This page is about a different variant/trim than selected.

NOTE: Test numbers refer to numbers on diagnostic chart.

Checks voltage signal from A/C pressure sensor to PCM. Normal voltage is 0.1-1.8 volts.
Checks to see if high signal is from a shorted sensor or a short to voltage in circuit. Normally, disconnecting sensor would make a normal circuit go to nearly zero volts.
Checks to see if low voltage signal is from sensor or circuit. Jumpering sensor signal circuit to 5-volt reference checks circuit, connections and PCM.
Checks to see if low voltage signal was due to an open in sensor circuit or 5-volt reference circuit. Previous step eliminated pressure sensor as a possible cause.

Fig 1: Code 66 Schematic (Corvette) A/C Pressure Sensor

Fig 2: Code 66 Diagnostic Flow Chart (Corvette) A/C Pressure Sensor