Models:
2015 – 2016 S3 and TTS
Condition:
A customer may complain of an engine droning noise or rattle noise when the engine speed is approximately 3,500 to 4,000 rpm (vehicle speed does not affect the noise, and the vehicle can be stationary).
The source of the noise seems to be from somewhere near the windshield or inside the dash panel area. The noise is more noticeable when the Audi drive select is set to dynamic mode. No DTCs are stored.
Technical Background:
In S3 and TTS vehicles, there is an electronic sound amplification system (actuator for impact sound) that changes depending on the selected Audi drive mode. The harness for the sound actuator can make contact with the vehicle body structure and the noise can be amplified by the sound actuator. This noise is only noticeable at higher speeds due to the calibration of the sound actuator system.
A video of the condition is located at https://audi-external.kzoplatform.com:443/swf/player/316 or scan the QR code in Figure 1.
Solution:
The harness for the sound actuator is covered with insulation tape.
Repair Procedure:
1. Verify the concern by checking for the sound with the engine speed between 3,500 and 4,000 rpm. Make sure the engine has reached operating temperature. This can be performed while the vehicle is stationary.
2. Check for the sound with the Audi drive select in comfort mode (see Figure 2).
3. Verify that the sound is more noticeable in dynamic mode.
4. If the sound is more noticeable in dynamic mode, then the source is the harness contacting the body structure and proceed to step 5. If not, further diagnosis might be necessary.
5. Loosen the connector R214 on the sound actuator (see Figure 3).
6. Wrap fleece tape from approximately 2cm away from the connector housing to the exit of the main wiring house (see Figure 4). The new tape can be placed over the existing insulation. The added bulk will dampen vibrations.
7. Check for the sound again to verify that the concern is resolved.