Boost Pressure Monitoring

The engine control module (ECM) monitors boost pressure continuously using information supplied by the mass air flow (MAF) sensor describing the intake air mass. If boost pressure exceeds the permissible level, the engine control module (ECM) will close the turbocharger (TC) control valve so that boost pressure is limited to its initial value. If the pressure continues to rise despite this adjustment, the engine control module (ECM) will interrupt the fuel supply by keeping the injectors closed. When pressure has dropped to a permitted level fuel injection is enabled again.

If the computations indicate that the boost pressure is too low, pressure will be limited to its initial value as the fault may be due to a blocked air intake for example.

If a fault occurs in a component that affects the calculation of boost pressure the engine control module (ECM) will only permit initial boost pressure.