The BAP sensor is supplied with a 5 V reference voltage at Pin 2 from ECM Pin X4–4 . The BAP sensor is grounded at Pin 1 from ECM Pin X4–24. The BAP sensor returns a variable voltage signal from Pin 3 to ECM at Pin X3–24.
Fault Detection / Management
When the ECM detects the BAP voltage signal out of range high or low, the ECM will ignore the BAP signal and use the Manifold Absolute Pressure (MAP) signal generated at low idle as an indication of barometric pressure. When a MAP fault is detected, the BAP signal will default to barometric pressure at sea level, 101 kPa (29.8 in Hg).
BAP Diagnostic Trouble Codes (DTCs)
DTCs are read using the EST or by counting the flashes from the amber and red ENGINE lamp.
DTC 151
BAP signal out-of-range high
• DTC 151 is set when the BAP signal is greater than 4.95 V for more than 0.5 second.
• DTC 151 can be set when the signal circuit is shorted to VREF or B+ or a failed BAP sensor.
• When DTC 151 is active the amber ENGINE lamp is illuminated.
DTC 152
BAP signal out-of-range low
• DTC 152 is set when the BAP signal is less than 1.0 V for more than 0.5 second.
• DTC 152 can be set when the signal circuit is shorted to ground or open, VREF is shorted to ground, or a failed BAP sensor.
• When DTC 152 is active the amber ENGINE lamp is illuminated.
Tools
• EST with MasterDiagnostics® software
• EZ-Tech® interface cable
• Digital Multimeter (DMM)
• Breakout Box
