Entertainment Systems - Overview BMW M3 E46

Model: E46

Production: From Start of Production

E46 Audio Systems

Two different sound systems will be available for the E46 at the start of production. The standard radio will feature the in-dash cassette player and the optional radio will have a single in-dash CD player. This is the first time that an in-dash CD player is available from BMW.

Both radios will be prewired for the optional 6-disc CD changer that mounts in the trunk.

The sound systems for the E46 continue with the integration feature introduced with the E38. The sound system is interfaced with the K-Bus to allow for amplifier and MFL communication.

Theft proofing of the radio via a code is no longer required as the radio will not function without the K-Bus connection and a valid K-Bus signal from the instrument cluster.

Also, the optional Harman Kardon sound system is available as an option from the start of production as well.

From March of 2001, the "New Generation" radios are available on the E46 which have new features and functions.

Scheme 1

A new feature of the sound system is the Radio Data System (RDS) display. RDS is a transmit and receive system operated in the FM band. It is a data service offered by radio stations, in which the information is transmitted inaudibly with the audio programs.

The name of the stations are displayed in the radio when the RDS system is active.

Carry over features of the sound system include

1. Autostore
2. Speed dependent volume (GAL)
3. Telephone muting
4. Radio test functions

Speakers

All models come standard with a 10-speaker sound system.

The speaker configuration is as follows

1. 160 mm Bass Speakers in front doors
2. 160 mm Bass Speakers in Rear Parcel Shelf
3. Tweeters in front door mirror triangle
4. Midrange speakers in all 4 doors (coupes in rear side trim panels)

Harman Kardon Sound System

The optional Harman Kardon audio system has been extensively refined for use in the 3 series. The speakers for the retain the same dimensions from the standard audio system, but are upgraded to higher standards.

The HK system add two 6x9 subwoofers which are positioned in the trunk in a subwoofer enclosure.

Depending upon application (i.e. coupe, sedan, convertible or sport wagon), the subwoofer configuration differs slightly in location.

Audio power is also increased by 40% and also features vehicle speed dependent equalization. This maintains audio sound quality consistent with changing interior noise levels.

Multi-Function Steering Wheel

The multi-function steering wheel of the E46 corresponds to the MFL introduced on the E38 and carried over to the E39. The wheel contains two key pads on the left and right side of the air bag that allow activation and control of various driver convince systems.

As with previous MFLs, the left side key pad contains controls for the sound system and telephone. The right side key pad contains the controls for the cruise control.

The K-Bus is used for data communication between the sound system/telephone controls.

The cruise control has its own data link to the engine control module (DME) for cruise control operation.

Scheme 2

Antenna Systems

The E46 radio systems are equipped with an antenna diversity system to provide the sound system with the best possible radio signal. This is achieved by the use of multiple antennae which are interconnected by the diversity module. Each antenna (depending upon application) has its own amplifier to improve signal strength.

The diversity module will select and lock on to the strongest signal and send information to the radio receiver.

Antenna Diversity

In the antenna diversity system, one antenna is connected for the AM band and three separate antennas for the FM range. The three FM signals received are switched in the diversity amplifier through to the radio cyclically via the RF line. The radio sends a feedback signal relating to the quality of the received antenna signal (the intermediate frequency signal) to the antenna diversity system. The antenna diversity system decides which of the three antennas has the best reception quality at present and switches this antenna through to the radio until the next measuring cycle is carried out. The antenna (FM1) arranged vertically in the rear window is used in the case of interference in the intermediate frequency signal.

Antenna System (Sedan/Coupe)

The AM, FM 1, FM 2 and FM 3 antennae are integrated into the rear window glass along with the rear window defroster grid. The antenna amplifier/diversity module is located under the left rear C-pillar trim and is connected to the radio receiver by a coaxial antenna cable.

Scheme 3

Antenna System (Convertible)

Due to the rear window configuration in a convertible, the antenna diversity system differs considerably from the Sedan/Coupe.

The antenna diversity system in the E46iC consists of

1. Rod Antenna
2. Diversity switching module/antenna amplifier mounted below the antenna mast
3. Diversity antenna integrated into convertible top storage cover
4. Amplifier for diversity antenna mounted on convertible top storage cover

The antenna for the telephone is wound around the main antenna mast.

Scheme 4

Scheme 5

Antenna System (Sport Wagon)

The basic configuration for the Sport Wagon antenna system is the same as for Sedan and Coupe. However, the component location is different due to the rear and side window layout.

The antenna system consists of the following

1. FM 1 Antenna is on the right side of the rear tailgate glass
2. FM 2 Antenna is located in the center of the rear tailgate glass
3. FM 3 Antenna is located in the left side rear window
4. AM Antenna is located in the rear spoiler
5. FZV Antenna is combined with the FM 2 Antenna

The amplifier for the FM 1 and FM 2 antennae is located beneath the rear spoiler. The signal from the amplifier is sent to the diversity module located in the left side storage compartment. The FM 3 antenna has a separate amplifier which is integrated into the diversity module.

Scheme 6

Diversity Switching

The FM1/FM2 amplifier can only send one FM signal at a time. The diversity module controls the switching of the signals by applying a voltage signal to the RF cable. When the voltage signal is low, the amplifier sends the FM 1 signal.

When the voltage level is high, it sends the FM 2 signal. The FM 1 and FM 2 inputs are continuously checked for the clearest signal. The diversity module then checks the signal from FM1/FM2 with the signal from FM 3. The clearest of these signals will always be sent to the radio for FM reception.

Scheme 7

FZV Antenna

The RF receiver module (315 MHz) is integrated into the antenna amplifier. The receiver has a separate KL 30 power supply for its operation. Signal from the FZV key are processed by the module and sent to the GM for locking/unlocking functions over a dedicated line.

New Generation Radios

Starting September 2000, a family of new generation radios will begin to be phased into production. The NG "New Generation" radios will have increased functions

1. Radio can be operated without KL R.
2. Radios are world frequency.
3. Car memory programming.
4. Audio mixing on vehicles equipped with navigation.

The radios external appearance has not changed. NG radios can be identified by their "53" designation.

NEW GENERATION RADIO APPLICATION CHART

Radio Operation With KLR Off

Operation is possible with the key off on the C53 and CD 53 radios. If the radio is turned on with KL R off, it will play at the last stored volume and settings for 16 minutes until the General Module sends the sleep command. No changes may be made to the radio unless KL R is switched back on. The radio can be turned on and off as many times desired.

Diversity Antenna

Antenna diversity has been adapted to the new generation of radios. When the radio is in operation, the diversity control unit is activated by the "RAD ON" signal.

World Frequency Radio

Radios on vehicles sold in the U.S. are world radios. Specific country settings can be made using the service mode. The settings are stored in an EEPROM.

Car Memory

If programmed, when locking the vehicle using the remote transmitter the following settings are stored according to key number used

1. Last station
2. Volume setting
3. Last audio mode (Tape, FM, CD etc.)

Unlocking the vehicle with the same transmitter will restore the settings. There is a maximum setting for volume which may be lower than the setting when the radio was last operated.

Clock

Time can also be displayed when KL R is off by pressing the clock button on the Radio/MID.

Backlighting

The LCM/LSZ produces two signals for the control of radio backlighting.

1. Hardwired KL 58g
2. Lights on/off over the K/I Bus.

The radio contains a photo-cell for adjustment of backlighting to ambient conditions.

Reset and Voltage Monitoring

A radio reset is triggered by under voltage or the internal processor monitor. The reset function restarts the radio, similar to turning it off and back on again. Operating voltage is measured at the KL 30 input. The radio is switched off if the system voltage exceeds 17 V to protect the radio, it will switch on when the voltage falls below 16 V.

GAL (Speed Dependent Volume)

The speed signal from the IKE/KOMBI is available to the radio over the K/I Bus. GAL is not a feature on vehicles equipped with DSP.

Bus Communication

The radio communicates with other modules via the K bus or I Bus dependent on the model. The information shared over the bus line includes

1. IKE/KOMBI - Terminal status (KL 15, KL R)
2. LCM/LSZ - Lights on
3. IKE/KOMBI link to TXD - Diagnosis
4. MID or BMBT - button or rotary knob status.
5. GM - Key used to lock or unlock vehicle
6. MFL - audio controls status

NG radios do not use anti-theft codes. Operation of the radio is only possible when connected to a bus line and the detection of at least one other component.

Service Mode For NG Radios

A service mode is available as on previous radios as a diagnosis tool and for changing radio settings. Entering the service mode varies by the device used to control the radio.

To enter the service mode

C53/CD53 with and without MID

1. Turn on the radio.
2. Within 8 seconds, press and hold the "m" button for 8 seconds.
3. Scroll through functions using the "+" and "-" keys or the station < > search buttons.
4. Turn off the radio to end the service mode.

C53 MIR

1. Turn on the radio.
2. Within 8 seconds, press and hold the "SEL" button for at least 8 seconds.
3. Scroll through functions using the station < > search buttons.
4. Turn off the radio to end the service mode.

BM53 with board monitor

1. Turn on the radio.
2. Press and hold the "RDS" button for at least 8 seconds.
3. Scroll through the functions using the station < > search buttons.
4. Turn off the radio to end the service mode.

BM53 with Widescreen board monitor

1. Turn on the radio.
2. Within 8 seconds, press the "INFO" button.
3. From the info screen select RDS
4. Press and hold the BM control knob for at least 8 seconds.
5. Scroll through functions using the station < > search buttons.
6. Turn off the radio to end the service mode

Service Mode Functions

1. Serial Number: Display of the radio serial number.
2. Software version: Display of the radio software version. Displayed as (calendar week, year, version)
3. GAL: Speed-sensitive volume control. Can be adjusted from level 1 -6 using the 6 preset audio buttons. Vehicles equipped with DSP do not use this feature.
4. Field strength and Quality (F/Q): The station currently displayed can be assessed for field strength and quality. An "F" (i.e. F15) number is used to indicate the strength of the signal being received by the radio. This is a good test of the antenna system, station signal, and the radio itself. A "Q" (i.e. Q-00) number is used to determine the quality of the radio station including both the audio and RDS signal if applicable.
5. DSP: This function provides information about whether the vehicle is fitted with DSP. The value is displayed as a one (fitted) or zero (not fitted) and is communicated by the DSP amplifier via the I/K bus.
6. TP Volume: Provides adjustment for traffic report minimum volume. Not for US.
7. AF: Alternative Frequency tracking setting. Not used in the US.
8. Area: Used to select the appropriate market setting (USA, Canada, Europe, Japan and Oceania). Adjust using the pre-set buttons.
9. Index: Display of the revision index.

Radio Test Functions (Non NG Radios)

Radio test functions are activated by pressing the "M" button within 8 seconds (and holding it pressed for 8 seconds) while switching the radio on. The test functions include

1. Radio serial number
2. Display of the software versions
3. Speed dependent volume control adjustment (1 -6)
4. Tuner 1 - Station signal strength

The FM frequency set, the signal strength and the quality of the signal received.

With RDS stations, the Program Identification, Program Service Name and RDS quality are also displayed.

The AM frequency set and signal strength are displayed.

1. Antenna signal strength (F number) - indicates the quality of the signal received by the antenna. The scale ranges from 0 to 15, with the optimum value being 15.

If the value falls below 10, radio stations can not be listened to in stereo.

1. Seek - Setting the seek sensitivity - allows the choice between two levels of seek sensitivity.

Diversity Antenna Diagnosis

The diversity function of the aerial amplifier can be checked by driving in a circle. For this purpose, the vehicle must slowly trace the circle.

Procedure

Set station in the FM range.

Disconnect intermediate frequency cable (IF cable, smaller coaxial connector) from the aerial amplifier/diversity amplifier

Slowly drive in a circle until reception quality of the station selected deteriorates and then stop the vehicle (if there is no deterioration in reception with the station selected, repeat the same procedure with a different, more suitable station)

Once a suitable station has been found and the point is reached where reception of the station is poor, the intermediate frequency cable (IF cable) must be reconnected and, as a result, reception should improve significantly.

Reconnecting the intermediate frequency cable allows the diversity function in the aerial amplifier to select the aerial structure with the best reception. When the intermediate frequency cable is disconnected, only one aerial structure is used and no search is implemented for the best possible aerial structure.