Waveform for exhaust flap actuator 17 BMW 330i

Autobahn44 · Post by **Autobahn44** » Mon Aug 30, 2021 4:44 pm

Anyone know what the waveform should look like to activate the exhaust flap?

Rfmotors1 · Post by **Rfmotors1** » Mon Aug 30, 2021 8:42 pm

Hi, I do not have BMW but I have one from Bentley, this is 4 wires variable flap motor. Power supply, ground, feedback wire reporting actual position of the flap by PWM, command wire reading signal from ECU what position is required. The flap motor is trying to achieve the same flap angle as reading from the command wire. There is basic setting necessary after replacement or removal and install back to learn the mechanical stop ends.
First the picture of the good known (new flap motor), engine running and playing with accelerator so the flap is changing position.

Next is the caprured file where is the flap actuated by diagnostic tester, max and min position.

Actuating the flap On Off by ODIS, Good Known flap motor.psdata: (4.87 MiB) Downloaded 466 times

Then the faulty flap motor, this was logging DTC once in few days only.

And finally the captured file of the faulty flap motor. Some explanation is in the notes and channel labels.

Faulty flap motor.psdata: (2.83 MiB) Downloaded 478 times

Hope it helps.
Regards,
Roman

vasek · Post by **vasek** » Tue Aug 31, 2021 10:26 am

Hi.
The flap is controlled by a PWM signal.
The control is stepless.
PWM=5% closed, PWM=95% open.
So if you want to have an M-Bimmer for F30 (

), you should apply PWM=95% control to the pin1 violet wire.
Forever and ever.))

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