Sensor Accuracy
With ignition on and engine off, pressure signal is equal to atmospheric pressure with signal high. This information is used by control module as an indication of altitude. Comparison of this reading with a known good vehicle with same sensor is a way to check accuracy of suspect sensor. Reading should be the same within 0.4 volt.
- Disconnect sensor from bracket and twist sensor by hand to check for intermittents. Output changes greater than 0.1 volt indicate a bad sensor or connection.