Audio, Visual & Navigation System (Base Audio Without Navigation): Overview

Component Description

Part name	Description
AV control unit	It is the master unit of the MULTI AV system, and it is connected to each control unit by communication. It operates each system according to communication signals from the AV control unit. The AV control unit includes the audio, USB connection and vehicle status functions. It is connected to each control unit via CAN communication to obtain necessary information for the vehicle information function. It is receives a steering angle signal from the steering angle sensor via CAN communication and controls an expected course line during rear view monitor operation. It inputs the illumination signals that are required for the display dimming control. It inputs the signals for driving status recognition (vehicle speed, reverse and parking brake). TEL voice signal and voice guidance signal are input from TEL adapter unit. Camera image signal is received and transmitted to display unit.
Display unit	Display image is controlled by the serial communication from AV control unit. It receives the power (signal VCC and inverter VCC) from the AV control unit and operates. RGB image signal is input from AV control unit (RGB image, RGB area and RGB synchronizing). Composite image signals are input from AV control unit. Synchronizing signal (HP, VP) is output to AV control unit.
Active noise control unit	Generates an antiphase sound weakening interior engine booming noise, mixes the antiphase sound with a sound signal transmitted from the AV control unit, and transmits the mixed sound signal to each speaker. Input microphone signal from front/rear microphone (for active noise control system).
Front door speaker	Outputs sound signal from active noise control unit. Outputs high, mid and low range sounds.
Front door squawker	Outputs sound signal from active noise control unit. Outputs high and mid range sounds.
Rear door speaker	Outputs sound signal from active noise control unit. Outputs high, mid and low range sounds.
Front microphone (for active noise control system)	Detects interior engine booming noise and transmits a sound signal picked up by the front microphone to the active noise control unit.
Rear microphone (for active noise control system)	Detects interior engine booming noise and transmits a sound signal picked up by the rear microphone to the active noise control unit.
Multifunction switch	Operation panel is equipped with the centralized switch where audio and air conditioner, etc. operations are integrated. Connected with preset switch via cable, and operation signal is transmitted to AV control unit via AV communication. The disk ejection operating signal is performed by hardwire.
Preset switch	Operation panel is equipped with the centralized switch where audio operations are integrated. Connected with multifunction switch via cable, and operation signal is transmitted to AV control unit via AV communication.
Rear view camera	Camera power supply is input from AV control unit. The image of vehicle rear view is transmitted to display unit via AV control unit.
Steering angle sensor	It is connected to the AV control unit and transmits the steering angle sensor signal via CAN communication.
Steering switch	Operations for audio, hands-free phone and voice recognition etc. are possible. Steering switch signal (operation signal) is output to AV control unit.
Microphone (for TEL)	Used for hands-free phone and voice recognition operation. Microphone signal is transmitted to TEL adapter unit. Power (Microphone VCC) is supplied from TEL adapter unit.
Antenna amp.	Radio signal received by window antenna is amplified and transmitted to AV control unit. Power (antenna amp. ON signal) is supplied from AV control unit.
Satellite radio tuner	Inputs the satellite radio signal from satellite radio antenna and outputs the sound signal to the AV control unit. It is controlled with the AV control unit and serial communication (communication signal and request signal).
Satellite radio antenna	Satellite radio signal is received and transmitted to satellite radio tuner.
TEL adapter unit	Inputs the TEL voice signal from TEL antenna and outputs it to the AV control unit. It is connected with the AV control unit via AV communication and controlled with the AV control unit.
TEL antenna	Receives the TEL voice signal and outputs it to the TEL adapter unit.
USB connector	Sound signal of USB input is transmitted to AV control unit.

Scheme 1

Scheme 1: MULTI AV SYSTEM: System Diagram

Note. The name MULTIFUNCTION SWITCH indicates the integration of PRESET SWITCH and MULTIFUNCTION SWITCH virtually.

MULTI AV SYSTEM: System Description

Multi AV system means that the following systems are integrated.

FUNCTION NAME
Audio function
Hands-free phone function
Rear view monitor function
Vehicle information function

Description

The AV control unit diagnosis function starts up with multifunction switch operation and the AV control unit performs a diagnosis for each unit in the system during the on board diagnosis.
Perform a CONSULT diagnosis if the on board diagnosis does not start, e.g., the screen does not display anything, the multifunction switch does not function, etc.

The trouble diagnosis function has a self-diagnosis mode for conducting trouble diagnosis automatically and a confirmation/adjustment mode for operating manually.
Self-diagnosis mode performs the AV control unit diagnosis and the connection diagnosis between each of the units that make up the system, and it indicates the results to the display unit.
The confirmation/adjustment mode allows the technician to check, modify or adjust the vehicle signals and set values, as well as to monitor the system error records and system communication status. The checking, modifying or adjusting generally require human intervention and judgment (the system cannot make judgment automatically).

Mode		Description
Self Diagnosis		AV control unit diagnosis. Diagnoses the connections across system components, between AV control unit and each unit.
Confirmation/Adjustment	Display Diagnosis	The following check functions are available: color tone check by color spectrum bar display and white display, light and shade check by gradation bar display.
	Vehicle Signals	Diagnosis of signals can be performed for vehicle speed, parking brake, lights, ignition and reverse.
	Speaker Test	The connection of a speaker can be confirmed by test tone.
	Climate Control	Start auto air conditioner system self-diagnosis.
	Error History	The system malfunction and the frequency when occurring in the past are displayed. When the malfunctioning item is selected, the time and place that the selected malfunction last occurred are displayed.
	Camera Cont.	Guiding line position that overlaps rear view camera image can be adjusted. Configuration stored in the AV control unit can be checked.
	Vehicle CAN Diagnosis	The transmitting/receiving of CAN communication can be monitored.
	AV COMM Diagnosis	The communication condition of each unit of Multi AV system can be monitored.
	Delete Unit Connection Log	Erase the connection history of unit and error history.
	Initialize Settings	Initializes the AV control unit memory.

ON BOARD DIAGNOSIS ITEM DESCRIPTION

Scheme 2

Scheme 2: METHOD OF STARTING

Scheme 3

Start the engine.
Turn the audio system OFF.
While pressing the "SETTING" button, turn the volume control dial clockwise or counterclockwise for 40 clicks or more. (When the self-diagnosis mode is started, a short beep will be heard.) Shifting from current screen to previous screen is performed by pressing "BACK" button.
The trouble diagnosis initial screen is displayed, and then the items of "Self Diagnosis" and "Confirmation/Adjustment" can be selected.

Scheme 4

Scheme 4: SELF-DIAGNOSIS MODE

Scheme 5

Start the self-diagnosis function and select "Self Diagnosis". Self-diagnosis subdivision screen is displayed, and the self-diagnosis mode starts. The bar graph visible on the center of the self-diagnosis subdivision screen indicates progress of the trouble diagnosis.
Diagnosis results are displayed after the self-diagnosis is completed. The unit names and the connection lines are color-coded according to the diagnostic results. Diagnosis results Unit Connection line Normal Green Green Connection malfunction Gray Yellow Unit malfunction (1) Red Green (1) Control unit (AV control unit) is displayed in red. Replace AV control unit if "Self-Diagnosis did not run because of a control unit malfunction" is indicated. The symptom is AV control unit internal error. Refer to " «REMOVAL AND INSTALLATION»(ref-573615-S41908307542013082200000) ". If multiple errors occur at the same time for a single unit, the screen switch colors are determined according to the following order of priority: red > gray. The comments of the self-diagnosis results can be viewed with a component in the diagnosis result screen.

ECU IDENTIFICATION

The part number of AV control unit is displayed.

Since vehicle specifications are not included in the AV control unit after replacement, it is required to write vehicle specifications with CONSULT.
The AV control unit configuration includes functions as follows.

Function		Description
Read/Write Configuration	Before Replace ECU	Allows the reading of vehicle specification written in AV control unit to store the specification in CONSULT.
Read/Write Configuration	After Replace ECU	Allows the writing of the vehicle information stored in CONSULT into the AV control unit.
Manual Configuration		Allows the writing of the vehicle specification into the AV control unit by hand.

CAN (Controller Area Network) is a serial communication line for real-time application. It is an on-vehicle multiplex communication line with high data communication speed and excellent error detection ability. Many electronic control units are equipped onto a vehicle, and each control unit shares information and links with other control units during operation (not independently). In CAN communication, control units are connected with 2 communication lines (CAN-H, CAN-L) allowing a high rate of information transmission with less wiring. Each control unit transmits/receives data but selectively reads required data only.

CAN Communication Signal Chart. Refer to " CAN COMMUNICATION SYSTEM: CAN COMMUNICATION SIGNAL CHART ".

U1300 is indicated when malfunction occurs in communication signal of multi AV system. Indicated simultaneously, without fail, with the malfunction of control units connected to AV control unit with communication line. Determine the possible malfunction cause from the table below.

Transmit the image displayed with AV control unit with RGB signal to the display unit.

Transmit the RGB synchronizing signal to the display unit so as to synchronize the RGB image displayed with AV control unit.

Transmits the display area of RGB image displayed by AV control unit with RGB area (YS) signal to display unit.

AV control unit outputs camera power supply to rear view camera and inputs rear view camera image signal from rear view camera when the reverse signal is input.
The AV control unit that inputs the camera image signal transmits the camera image signal to the display unit.

AV control unit that inputs the camera image signal transmits the composite image signal to the display unit.

In composite image (camera image), transmit the vertical synchronizing (VP) signal and horizontal synchronizing (HP) signal from display unit to AV control unit so as to synchronize the RGB images displayed with AV control unit such as the image quality adjusting menu, etc.

The eject signal is output to AV control unit when the eject switch of multifunction switch is pressed.

Supply power from TEL adapter unit to microphone. The microphone transmits the sound/voice to the microphone.

TEL adapter unit identifies the vehicle model according to the control signal and performs the control.

Transmits the steering switch signal to AV control unit.

OPERATION

Symptoms	Check items	Possible malfunction location/Action to take
Multifunction switch and preset switch operation does not work.	All switches cannot be operated. "MULTI AV" is displayed on system selection screen when the CONSULT is started.	Multifunction switch power supply and ground circuit. AV communication circuit between AV control unit and multifunction switch. Perform "Self diagnosis Result" of "MULTI AV" with CONSULT. Refer to " CONSULT FUNCTION ".
	All switches cannot be operated. "MULTI AV" is not displayed on system selection screen when the CONSULT is initialized.	AV control unit power supply and ground circuit malfunction. Refer to " AV CONTROL UNIT: DIAGNOSIS PROCEDURE ".
	Only specified switch cannot be operated.	Multifunction switch or preset switch malfunction. Perform multifunction switch and preset switch self-diagnosis function. Refer to " ON BOARD DIAGNOSIS FUNCTION ".
Fuel economy display, vehicle setting operation is abnormal.	There is malfunction in the CONSULT self-diagnosis result. Refer to " CONSULT FUNCTION ".	Perform detected DTC diagnosis. Refer to " DTC INDEX ".
	There is no malfunction in the self-diagnosis results. Refer to " CONSULT FUNCTION ".	Ignition signal circuit malfunction. (AV control unit)

BASIC OPERATIONS

Symptom	Possible cause	Possible solution
No image is displayed.	The brightness is at the lowest setting.	Adjust the brightness of the display.
	The systems in the video mode.	Press "DISC-AUX" to change the mode.
	The display is turned off.	Press " / OFF" to turn on the display.
The screen is too dim. The movement is slow.	The temperature in the interior of the vehicle is low.	Wait until the interior of the vehicle has warmed up.
Some pixels in the display are darker or brighter than others.	This condition is an inherent characteristic of liquid crystal displays.	This is not a malfunction.
Some menu items cannot be selected.	Some menu items become unavailable while the vehicle is driven.	Park the vehicle in a safe location, and then operate the multi AV system.

Audio, Visual & Navigation System (Base Audio Without Navigation): Overview Infiniti M37 IV