The space static pressure sensor diagnostic occurs when the voltage output from the transducer is outside the range for normal pressures. Normal pressures range from -.67 IWC to .67 IWC. During normal operation if the voltage dips below 0.04 VDC or rises above 0.75 VDC the diagnostic will be generated.
Note: The sensor is capable of responding to pressures from -.75IWC to 9 IWC, but the controls can only read values in the range of -.67 IWC to .67 IWC as valid for space pressure.
This diagnostic can also be generated if the calibration solenoid is not functioning properly. For one second every minute, the calibration solenoid is energized to zero out the transducer. It connects the high port and the low port to outside air static reference. The controls expect to see .0.254DCV @ 0.00 IWC during this time. Any difference from this value is used as an error amount and used to adjust the sensor reading for the next minute. If the calibration solenoid is not functioning, the controls will not receive the correct error signal and will interpret the sensor reading as zero pressure. In these cases, if power is cycled to the unit, the sensor will read correctly for one minute and then read decline to 0.00 IWC before giving the diagnostic.
Items to check include:
- wiring
- sensor
- calibration solenoid
- control module (6KF16)
- pneumatic tubing connections