The Barometric Pressure Sensor (BPS) is located between the air cleaner assembly and the throttle body. It detects the atmospheric pressure at the vehicle's current location. The barometric pressure sensor signal is used to calculates the density of the air. The Barometric Pressure Sensor plays an important role when driving in the mountains and in different altitiudes.
In the case of sensor failure, in many cases, the ECM will calculate a value to substitute for the failed sensor signal. The ECM can also use this calculated value to check the performance of working sensors by comparing the sensor's actual value to the calculated value. If the actual BPS is higher or lower than calculated value(threshold) for more than 31.25seconds the ECM determines that a fault exists and a DTC is stored. Because the calculated value is based on other sensor outputs, an inaccurate sensor signal will change the calculated value. If no problem is found with the Baro sensor, check the other sensors.
Item
Detecting Condition
Possible cause
DTC Strategy
The BPS Rationality Diagnostic compares the difference between BPS output and calculated value to a calibration value
Clogged air cleaner
BPS
Enable Conditions
Engine runing
10V< Battery Voltage < 16V
Threshold value
Acutal BPS Value is higher or lower than calculated value
Diagnosis Time
Continuous (within 31.25sec.)
MIL On Condition
2 Drive Cycles
Pressure(kPa)
Voltage(V)
10.0
0.50
55.0
2.21
100.0
3.93
115.0
4.50
Fig 1) Normal data & waveform of BPS at approx. 1 atm condition.