jbmercapple
28-03-2020, 06:17 PM
Last summer I realised that the active exhaust wasn’t working on my 2013 Bitdi. A scan with VCDS gave the fault ‘Actuator 1 open circuit’. I checked the wiring and carried out a bit of research and it didn’t seem to be a common fault but as the actuator is built into the rear silencer, I didn’t fancy forking out £600 for a new one so decided to live with it.
Fast forward to now where we are in lockdown and I’ve got a lot more time on my hands, I thought I’d look into it again. I found a company in Germany that offered a repair service for £300, but as this required me to cut off my silencer and send it to them I decided it was too much hassle. However, a useful photo on their website showed a silencer cut open to reveal the inner workings. Very interesting…. The actuator is just a loudspeaker with the sound being piped to the tail pipe.
I decided to connect an old spare speaker from a multimedia setup to the control unit and see what happened. The easiest way was to splice into the loom with scotchlock connectors near the plug to the controller. Terminals 5 and 6 are Actuator 1. I connected it up inside the boot, cleared the fault code with VCDS and started up. Success! Active exhaust working again.
Now I had to decide where to put the speaker which is in an enclosure approx. 6 x 4 x 4 inch. Actuator 1 is on the passenger (left) side, so looking inside the storage panel I found a perfect space below the rear light. But even better, there is a 4 inch square air pressure vent in the back panel. This has gravity rubber flaps that I wedged open with a piece of foam and then my speaker fitted perfectly in the space, pointing the sound out through the vent which is behind the bumper about 6 inches above the tail pipe. I ran the cabling across the boot behind the rear trim.
I started the engine and the noise externally is just as it should be, but a bonus is that the sound internally is much better than before. As the speaker is basically in the boot, you get a much better (louder) exhaust sound. Switch to Comfort mode and it turns off for more relaxed cruising.
I’ve only managed a short test drive to the supermarket due to the current travel restrictions but I’m really happy with the result so thought I’d share it with others as instead of spend upwards of £300 it cost me nothing.
Fast forward to now where we are in lockdown and I’ve got a lot more time on my hands, I thought I’d look into it again. I found a company in Germany that offered a repair service for £300, but as this required me to cut off my silencer and send it to them I decided it was too much hassle. However, a useful photo on their website showed a silencer cut open to reveal the inner workings. Very interesting…. The actuator is just a loudspeaker with the sound being piped to the tail pipe.
I decided to connect an old spare speaker from a multimedia setup to the control unit and see what happened. The easiest way was to splice into the loom with scotchlock connectors near the plug to the controller. Terminals 5 and 6 are Actuator 1. I connected it up inside the boot, cleared the fault code with VCDS and started up. Success! Active exhaust working again.
Now I had to decide where to put the speaker which is in an enclosure approx. 6 x 4 x 4 inch. Actuator 1 is on the passenger (left) side, so looking inside the storage panel I found a perfect space below the rear light. But even better, there is a 4 inch square air pressure vent in the back panel. This has gravity rubber flaps that I wedged open with a piece of foam and then my speaker fitted perfectly in the space, pointing the sound out through the vent which is behind the bumper about 6 inches above the tail pipe. I ran the cabling across the boot behind the rear trim.
I started the engine and the noise externally is just as it should be, but a bonus is that the sound internally is much better than before. As the speaker is basically in the boot, you get a much better (louder) exhaust sound. Switch to Comfort mode and it turns off for more relaxed cruising.
I’ve only managed a short test drive to the supermarket due to the current travel restrictions but I’m really happy with the result so thought I’d share it with others as instead of spend upwards of £300 it cost me nothing.