Exhaust Flap Damper Control

EXHAUST FLAP DAMPER CONTROL (MS41.1 328 & 323i/is Models)


To meet European noise level compliance, the silencer of the the above noted vehicles incorporate a flap that is designed to reduce exhaust noise at idle, low RPM and while coasting. Components of the system include:

- Exhaust flap with vacuum actuator
- Vacuum reservoir
- Switching solenoid
- Check valve

OPERATION







The MS41 .1 Control Module will power the switching solenoid and apply vacuum to the exhaust flap actuator for the following conditions:

- Engine idle - up to 2500 RPM
- Engine decel

This will close the flap allowing additional damping of the exhaust to take place.

The solenoid will switch OFF when accelerating above 2500 RPM. The vacuum is vented from the flap actuator and the flap opens. This allows the M52 engine to make maximum use of the backpressure effect for improved torque response