P1599

Tests 1 - 3:

Tests 4 - 7:

SYMPTOM
P1599 - A/C PRESSURE SENSOR VOLTS TOO LOW

WHEN MONITORED
With the ignition ON, the engine running, and the A/C relay energized.

SET CONDITION
The A/C pressure sensor signal voltage at the PCM goes below 0.5 volts, or is below 0.7 volts for 22 seconds when the A/C relay is energized.

POSSIBLE CAUSES
- Intermittent wiring & connectors conditions
- A/C pressure sensor 5 volt supply circuit open
- A/C pressure sensor signal circuit shorted to ground
- A/C pressure sensor signal circuit shorted to sensor ground circuit
- A/C pressure sensor ( voltage > 1.0 volt)
- Powertrain control module