Module, Active Noise Cancellation (ANC): Operation
- The Active Noise Control (ANC) module performs the creation of signals appropriate to cancel engine order related vehicle noises from the engine. It creates these signals in proportion to the Engine RPM plus any other needed input.
- The ANC module obtains the engine RPM from the vehicle Powertrain Control Module (PCM).
- The signals that the ANC module creates includes at least four simultaneous signals equivalent to sine wave frequencies in designated ratios tracking the engine RPM, to cancel engine order related noises, plus other optional signals that can enhance the cancellation effect.
- To maintain the effectiveness of the noise cancellation over the full range of vehicle operating conditions and seating locations, the ANC module has four outputs and process signals from four microphone assemblies located in the headliner.
- The ANC module supports mixing the four ANC signals into any output channel at a point after all of the signal processing required
- The ANC module operates on vehicle battery power and has its state of operation controlled by CAN-B bus messages.
- In addition to performing active noise cancellation, the ANC module supplies power to the loudspeakers.
The ANC module variants are a number of channels, load impedance capabilities, and gains specified in the following table:
| ANC MODULE VARIANTS | |||
|---|---|---|---|
| ANC MODULE VARIANT | Number of Channels | Load Impedance | Gain & Audio Processing |
| ANC Module- Base | 4 | 4 | 0 dB & None |
| ANC Module- Premium | 4 | 2 | 0 dB & None |
| Integrated | 8 or 12 | 2 | - |
The hard wired circuits between components related to the ANC module may be diagnosed using conventional diagnostic tools and procedures. Refer to the appropriate wiring information. The wiring information includes wiring diagrams, details of wire harness routing and retention, connector pin out information and location views for the various wire harness connectors, splices and grounds.
However, conventional diagnostic methods will not prove conclusive in the diagnosis of the ANC module or the electronic control and communication features of the ANC module. The most reliable, efficient and accurate means to diagnose the ANC module or the electronic control and communication features related to ANC module operation requires the use of a diagnostic scan tool.