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Nav Radio Upgrade (with Streaming)

  • Model & Year: 98-01 7-Series, U.S.
  • Expertise: Intermediate
  • Date: May 20, 2019
  • Updated: July 11, 2019
  • Time Estimate: varies

Tools Required

  • Basic hand tools
  • NavCoder or other coding software

Facilities Needed

  • None

Parts Required

  • BM53 Radio: see below for details, $120 - $300 (used),
  • Radio Adapter: 61-12-6-913-957, $75 new retail,
  • Antenna Adapter: 61-12-6-913-955, $35 new retail,
  • Optional CD/MP3 Changer Adapter:
    • Standard Audio: 61-12-6-913-954, $28 new retail
    • DSP Audio: 61-12-0-140-718, $40 new retail
  • Optional Input Adapters:
    • Bluetooth Audio Streaming Dongles, various, $12 - $40 (see below)
    • Aux Input, various, $7 - $40 (see below)
    • Sirius Satellite Radio Module & Wiring (see below)

ADVISORY: Like other electronics produced today, the BM53 suffers from quality problems that affect its useful life. Specifically, its onboard amplifiers fail, resulting in loss of sound output to the speakers. This well-known issue is addressed by many online repair services starting around $150. Search keywords "BM53 radio repair". Source a refurbished BM53 or, get yours serviced preemptively before installation.

Getting Started

Upgrading your standard trunk-mounted navigation radio from the Alpine C43 model to the "new generation" Becker BM53 will open a new world of possibilities.

For starters, the BM53 has a dedicated aux-in channel. This allows audio input from any source thru standardized input adapters by simply toggling your nav's MODE button to the new "Aux" channel. Now, music playback from an iPod or other device is possible (keep your device handy, since you'll control your music from the device).

Additionally, factory Sirius satellite radio operates thru the BM53 (with Mk4 navs). The BM53 also works with factory MP3 CD changers (plug-n-play replacement of stock changer) which display Audiotext, technically known as ID3 tags. Audiotext provides song title, artist, and album descriptions on Mk4 navs to assist in the playback and navigation of large - properly tagged - mp3 collections. (Audiotext works only with factory MP3 changers [not iPods, etc], and ID3 graphics [album art] is not supported.)

But perhaps most interestingly, Bluetooth audio streaming is possible using aftermarket adapters available from a variety of sources (see below for more). These adapters plug directly into the BM53 and require a 12 volt power supply, available from the nearby radio wiring.

Audio streaming is very popular and is commonly achieved thru aftermarket devices such as Grom. Although the Grom device is perfectly workable (but somewhat buggy), it displaces the CD changer and, for those who prefer a factory Bluetooth TCU for hands-free phone, will result in unneccessary duplication of telephone functionality. By contrast, the BM53 streaming option isolates streaming to a dedicated channel and is for audio only. Therefore, it does not duplicate TCU operation and leaves the CD channel open for use with a changer, factory Sirius radio, aftermarket XM radio, or even an aux input.

For those with DSP audio, a bonus: the BM53 no longer requires expensive and complex DSP adapters to route digital audio into the DSP amplifier. Instead, analog audio can optionally be routed directly from your aftermarket device (like Grom) into the new radio. This creates in effect a "standard" audio system, eliminating the neccessity of DSP adapters for aftermarket devices.

This change results from configuring the nav computer to recognize a BM53 radio instead of the C43 by using NavCoder or similar software. This is an important step, especially for DSP audio, otherwise your new radio may not function correctly. (Ask me how I know!) Don't worry, making this change with NavCoder involves only a single point-and-click operation.

BM53 Radio

The radio itself is a surprisingly lightweight and unassuming aluminum box. BMW offered several different models thru the years, updating it frequently. Choose the model with features you desire:

Production Model Aux Sirius** ID3***
09/01/01 - 03/01/02 65-12-6-904-213(4*)      
03/01/02 - 10/23/02 65-12-6-919-080(1*)      
09/01/02 - 07/28/03 65-12-6-922-512(3*)    
12/01/02 - 07/17/03 65-10-6-933-089(90*)    
08/01/03 - 11/23/04 65-12-6-927-910(1*)  
09/01/04 - 11/23/04 65-12-6-943-449(50*)  
11/15/04 - 01/27/06 65-12-6-964-398(9*)  
03/01/05 - 10/18/05 65-12-6-972-662(5*)  
09/01/05 - 07/26/06 65-12-6-976-961(2*)
03/01/06 - current 65-12-6-988-275(6*)
   * remanufactured model number    ** requires Sirius module 65120439436 and adapters    *** requires mp3 changer 65129131852

Note early models didn't support aux-in, while only late models support ID3 Audiotext. Used models start around $120 (from eBay, for example). Naturally, newer models with more features fetch higher prices. Sourcing a remanufactured model should avoid the "bad amp" issue mentioned in advisory above.

Many eBay sellers offer these radios complete with snipped electrical connectors. This allows splicing into existing wiring and avoids the need to purchase wiring adaptors (specified above). But beware: a cut-n-splice approach takes place within very limited room inside your trunk, and may result in back aches and crossed wires. Those who prefer an easy, reversible, plug-n-play installation should use wiring adapters.

The BM53 radio is configured to accept two 12-pin inputs on the rear. BMW previously used 10-pin connections on their radios but switched to this new standard in 9/01, which is shared by other makes such as Audi, Mercedes, and Porsche. The left input accepts white plugs and is coded for CD (nav displays "CD") while the right accepts black plugs and is coded for auxilliary (nav displays "Aux").

And now for the magic:

These inputs may be used interchangeably and in combination, with a host of aftermarket or factory devices. For example, the BM53 can accept two aux inputs. Or, it can accept a BT streamer and aux-in. This flexibility is key to the BM53's appeal. See diagram below:

After installation, use NavCoder or other coding software to switch radio settings. See Procedure section below for more.

Bluetooth Audio Streaming

Finally! A factory-like way to stream Bluetooth audio from your phone! Listen to Pandora or Spotify in your E38 7-series, or stream your personal mp3 collection.

Mostly plug-n-play, these streaming "dongles" are sold by a variety of sources such as Amazon and eBay, starting at $12. Really. To purchase, simply perform an Internet search using keywords "bmw 12 pin bluetooth adapter".

These devices require a power/ground connection, readily available from the nearby radio connector. Since the wire length provided by these adapters is short (about 10"), the receiver "puck" will need to be secured to the nearest flat surface. See Procedure section below for details. And although the receiver will be in the trunk, your phone will have no trouble connecting. Note:

  • Black plugs connect to Aux channel. White plugs connect to CD channel. Select appropriate input from nav MODE button.
  • BT streaming devices are not for hands-free telephone use. Streaming is for music playback only. Bluetooth telephone functions require either a factory TCU or aftermarket BT phone device (such as Grom).
  • Control over streaming music comes from your phone, so keep it handy while driving (but please don't become a distracted driver!). Streaming draws considerable battery power, so consider Phone Charging & Signal Boosting.

Isolating audio streaming to a dedicated input channel leaves the other channel open and does not duplicate factory TCU functionality. Like all BMW radios, the BM53 mutes all radio audio when in-call.

Sirius Satellite Radio

Full factory integration of Sirius satellie radio is possible with a Mk4 nav, full screen monitor, BMW Sirius receiver, and a Sirius-capable BM53 radio. The Sirius receiver daisy-chains off the CD changer input with its adapter wiring, allowing full use of both components. For a full description of this installation including required parts see:

Of course, satellite radio requires a subscription fee.

CD/MP3 Changer

To retain use of a stock changer or existing aftermarket Bluetooth adapter (such as Grom), or to install a factory MP3 changer or Sirius module, an adapter cable will be needed. There are options, beginning with whether or not your car has DSP audio:

Cable '718 comes un-pinned (for use with various radios) and therefore requires manual pinning of the connector. This task is straightforward and takes 5 minutes (for pin-outs, see diagram A above). Remember, the existing mini-cable that routes digital audio into the DSP amplifier may be discarded. Instead, analog audio can be routed directly into the new radio creating in effect a standard audio system, eliminating the need for aftermarket "DSP adapters". All devices including CD changers and Grom adapters connect directly to this cable.

If you wish to retain the digital input with your DSP system you may do so. The BM53 auto-detects the interface in use (analog or digital). While using the digital input negates the need for cable '718, it requires DSP adapters for aftermarket devices (as before).

Cable '954 converts older 10-pin connectors to the new 12-pin style. It must be joined to your existing cable using heat-shrink tubing since there is no securing mechanism between the two cables. (Use of electrical tape or other is not advised, since these methods deteriorate over time.) See C43 Radio Connections image in Procedure section below.

Alternatively, non-DSP cars could also use cable '718 and ignore their existing cable. This avoids the joining issue for cable '954. In fact, any BMW can use cable '718 with the BM53.

Supplement: Build a CD Connection Cable for under $20.

And if your 7-series was built before 9/98 and has a Mk1 nav, use cable '718 coupled with a post-9/98 CD changer (or MP3 changer or BT streamer or...).

The MP3 changer is p/n 65-12-9-131-852 and requires cable '718. Note this changer is physically different than changers made for the E38 7-series and won't fit in the same spot. It will require an alternative mounting location (ex: suspended from trunk upper deck). But it's plug-n-play.


1/8" mini jack connections can be found everywhere for the BM53 radio. They are commonly available from online sources such as eBay and Amazon, ranging in price from $7 to $9. There are variations of this input type as well, depending on the device you wish to connect. For example, an RCA-type input adapter is available:

To purchase, simply perform an Internet search using keywords "bmw 12 pin aux-in". If you prefer the factory aux-in, use part number 82-11-0-149-390 (about $40).

The BM53 can accept two aux-inputs, connected simulaneously or in either channel. Note:

  • Black plugs connect to Aux channel. White plugs connect to CD channel. Select appropriate input from nav MODE button.

A suggested mounting location for the mini jack input is in the glovebox or inside the ashtray. Generic extension cables may be required to obtain the length needed to run the input to the front of the car.

A benefit of using an aux input versus streaming BT music is that the aux method avoids A2DP compression losses, since music is routed directly into the radio. This means your music may sound a bit better using an aux-in.


Navigation radios reside behind the audio amplifier in the left-rear trunk. To gain access, it's necessary to unplug and remove all existing electronic gear along with their mounting brackets.

1) Remove nav computer, then remove side trim to expose existing electronics gear.

2) Remove the three different brass-colored brackets which hold electronics such as the CD changer, Telephone Control Unit (TCU), SES voice module, and audio amplifier.

  • The outermost bracket holds the telephone antenna amplifier, TCU (9/00-on), and optional video module. Its three 8mm fastners are shown in image above left (red arrows).
  • The middle bracket holds the CD changer and SES voice module (9/00-on), and is secured with a single fastner at the rear.
  • The innermost bracket holds the amplifier and TCU (thru 9/00). After removing the amp, the bracket's five 8mm fastners become visible, shown in image above right. Release attached wire ties also.

DSP Audio Amplifiers

A digital mini-cable runs directly from the CD changer or aftermarket DSP adapter (such as Grom) into the amp, as shown in image below. If installing CD changer cable '718, unplug and remove the cable along with any DSP adapter, since these items are no longer required with the BM53!

3) Release the two 10mm nuts securing the nav bracket and remove nav bracket. This makes room for radio removal.

4) With all brackets removed, locate the two plastic rivets holding the black fabric that hides the radio. See image below (nav with bracket shown for orientation purposes). Pry out the rivet pin, then the plug. Then carefully pull away black fabric cover.

5) The radio, secured in its own bracket, will now be visible:

The radio bracket is secured with two 8mm fastners, one of which is hidden behind the sunroof water drain tube. Unclip tube for access. See image above.

6) Extract radio with bracket from behind framing. Unplug all radio connections, then separate bracket after releasing its single 8mm fastner. For reference, connections are shown below:

Prepare Adapter Accessories

Gather all adapters and accessories to be used with the new BM53 radio (CD changer cable, BT streamer, aux-in adapter, etc).

7) Plug accessories into their appropriate slot in the radio wiring harness. Remember, white plugs feed the CD channel and black plugs feed the Aux channel. The plugs are keyed for correct installation. See illustration below:

In example above, the CD channel supports an RCA-type aux-in (for mp3 music device) and the Aux channel supports a Bluetooth audio streaming device.

If using aux-inputs (either 1/8" or RCA), be sure to have additional (generic) cable length on hand to extend to the front of the car.

Radio Installation

8) Attach radio bracket to BM53 and secure it with 8mm nut and washer or similar fastner. See image panel A below. (By contrast, the C43 is secured with 8mm screw fastner). Then connect radio wiring harness to BM53 (with attached accessories and adapters) along with antenna adapter.

9) Insert radio back into position in car and secure radio bracket with fastners. Then, mate wiring harness and antenna adapter to car (FM diversity cable goes unused). See image panel B above. (Note RCA-type aux adapter and BT streamer.)

10) Re-install black fabric cover and secure with rivets, then re-install all components and brackets in reverse order. Route wiring to appropriate locations.

Coding Radio

11) Before testing your installation, reconfigure your nav computer to work with the new BM53 radio. As previously described, NavCoder is ideal for this purpose. If you're new to NavCoder, see Using NavCoder for more specifics.

Select Code > Navigation to see the configuration dialog:

In the "Other settings" section, simply select Radio splitscreen enabled (New Gen Radio BM54/BM53). Then click "Code Nav" button. Done!

Optionally - while you're in there - verify the BM53 radio settings from Code > Radio:

See Using Navcoder for a full explanation of options in each of the two dialogs above.

The BM53 displays some new screens and options. For example, in CD mode, instead of displaying CD01-01, it displays TR01 for track numbering while the disc number is displayed in small font on the far right. There is also a "NAV-min" option available from INFO, and ranges from -9 to +9. It supposedly controls nav volume, but I cannot confirm this. It certainly does not affect "Nav Volume" from MENU.

You're all done! Now pair your phone and start streaming that audio!

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