Pinpoint Test Ac: Barometric Pressure Sensor: Description
Barometric Pressure (BARO) sensor is a variable capacitance sensor that when supplied with a 5-volt reference signal from Powertrain Control Module (PCM) produces a linear analog voltage signal that indicates pressure. DTC 0107 indicates BARO sensor circuit low input. DTC 0108 indicates BARO sensor circuit high input.
- Timing Control
BARO signal is used to determine altitude to adjust timing and fuel quantity to optimize engine operation and control smoke throughout all altitude conditions. - Glow Plug Control
BARO signal is one of the variables used to calculate glow plug ON time. At higher altitudes glow plug ON time is increased to insure faster clean up of start-up smoke.
Perform this test when directed here by QUICK TEST. A BARO sensor that is detected out of range (high or low) by PCM will cause PCM to ignore BARO sensor signal and use Manifold Absolute Pressure (MAP) sensor signal generated at low idle as an indication of barometric pressure.