DTC P1540 - Air By-Pass System, Open Or Short Circuit: Condition
WARNING: This page is about a different car, the 1997 Mazda Millenia. However, it is still accessible from the selected car via links, so may be relevant.
DTC is set when difference between actual charge pressure and target charge pressure is greater than 13.3 kPa. Possible causes are:
- Air By-pass Valve (ABV) vent and/or vacuum malfunction.
- Input system signal malfunction.
- ABV actuator malfunction.
- Vacuum system leakage or clog.