Audio DSP Module

APIM

The APIM can be operated with the ignition in RUN, ACC, or OFF.

The APIM receives stereo and mono inputs. Stereo inputs include audio from the USB ports, connected Bluetooth- enabled media device, and outside device during a phone call. The mono input includes signals from the SYNC® microphone.

The APIM sends stereo and mono audio signals to the ACM as fluctuating AC voltage. Stereo outputs include audio from the USB ports, connected Bluetooth-enabled media device, ringback tone, outside device during a phone call, voice or tone prompts initiated from the voice steering wheel switch, and instructions or information spoken by the SYNC® system when initiated from the voice steering wheel switch. Mono outputs include audio from the TTS feature, incoming call ringtone, instructions or information spoken by the SYNC® system when initiated from the FDIM, and navigation route guidance voice or tone prompts (if equipped with navigation).

For vehicles with navigation, the APIM receives SIRIUS Travel Link data from the ACM through the SDL circuits. This data is processed and sent to be displayed on the FDIM.

The TTS feature allows the customer to hear information through the audio system speakers so it does not have to be read from the FDIM and/or device while driving. Examples include incoming text message sender information, text messages, and metadata from audio being played via USB or Bluetooth.

The APIM consists of two internal modules: the CIP and the VIP. The modules are not replaceable individually, but can be programmed independently if required.

The CIP interfaces with all of the customer inputs to the APIM. It contains an analog-to-digital-to-analog converter, as well as the Bluetooth/Wi-Fi chipset.

The VIP provides an interface between the CIP and the vehicle inputs. Its main functions are controlling the APIM power management and translating inbound and outbound CAN signals.

The APIM provides the FDIM with power and ground through the LVDS (Low Voltage Differential Signaling) cable.

The APIM receives GPS data through the GPS coaxial cable. The data is used for the navigation system (if equipped) and SIRIUS Travel Link date/time-dependent features such as sports schedules and scores, movie times, and the 5-day weather forecast. The APIM also uses this data to identify the vehicle’s location in the event of a collision and to display the compass heading on the FDIM.

The APIM requires programming when it is replaced.

Audio DSP Module

The audio DSP module can be operated with the ignition in RUN, ACC, or OFF.

The audio DSP module enhances the input audio signal sound quality from the ACM.

The ACM outputs voltage through the enable circuit to enable the audio DSP module amplifier. When the ACM removes voltage from this circuit, the audio will be muted. When the ACM applies the correct amount of voltage to this circuit, the audio will be unmuted. In the event of an amplifier overload, the audio DSP module reduces audio levels on the left and right audio output channels to prevent clipping and speaker damage.

The audio DSP module receives stereo and mono audio signals from the ACM in the form of fluctuating AC voltage. The audio DSP module processes and amplifies these inputs and depending on the input received, sends stereo or mono analog audio signals to the speakers and subwoofer amplifier as fluctuating AC voltage.

When the engine is running, the audio DSP module receives the engine noise cancellation frequency signal (2.3L) and ESE frequency signal (2.3L and 5.2L) from the ACM in the form of fluctuating AC voltage. The audio DSP module sends the engine noise cancellation frequency signal to the LHF and RHF door woofer speakers, and left and right parcel shelf full-range (without Shaker) or coaxial (with Shaker) speakers (coupe) or RHR and LHR quarter panel full-range (without Shaker) or coaxial (with Shaker) speakers (convertible) as fluctuating AC voltage. The ESE signal is sent to the LHF and RHF door woofer speakers and right and left parcel shelf (with 5.2L) speakers as fluctuating AC voltage.

When the engine is running and the audio system is in use, the audio DSP module output to the LHF and RHF door woofer speakers contains a mixture of the engine noise cancellation and ESE frequency with the audio signals from the ACM. The output to the right and left parcel shelf full-range (without Shaker) or coaxial (with Shaker) speakers (coupe) or RHR and LHR quarter panel full-range (without Shaker) or coaxial (with Shaker)