The M coupe & Z3 coupe Site

FAQs on Stereo


How do I check or change the Speed Sensitive Volume (SSV) settings?

Enter Maintenance Mode:

  1. With the engine running and radio on, turn off the radio.
  2. Turn the radio back on and then (just before the radio display turns on) hold in on the "m" key for about 5 second or so until it goes into maintenance mode.
  3. Using the "+" or "-" keys, scroll to select GAL function, use the arrow keys <|m|> to set the "GAL" setting from 1 (min) to 6 (max) or use 1-6 preset keys. Default is 3. A lower GAL settings will result in a smaller increases in volume at a particular speed. A higher settings will have a larger change in volume.


How do I check or change the Maintenance Mode settings?

  1. With the engine running and radio on, turn off the radio.

  2. Turn the radio back on and then (just before the radio display turns on) hold in on the "m" key for about 5 second or so until it goes into maintenance mode.
  3. After holding "m" button to enter Maintenance Mode, it changes the LED screen to show the radio's serial number. "SN=xxxxxxxx"
  4. Use the "+" or "-" buttons for scrolling
  5. Press "+" to next function reads "GI 06", using the <|m|> arrows to scroll to, "HI 020101", "SIM 501100", "SIP 505020" and then back to "GI 06". No adjustment via any controls.
  6. Press "+" to "GAL" use the arrow keys <|m|> to set the "GAL" setting from 1 (min) to 6 (max) or use 1-6 preset keys. Default is 3.
  7. Press "+" and the radio station frequency is displayed along with two radio frequency signal strength meters that display the signal strength from 0-15. 15 is max signal strength.
  8. Press "+" shows "DSP 0 V 00". No adjustment via any controls.
  9. Press "+" shows a blank screen. Using the <|m|> arrows or 1-6 keys brings up different test patterns to test the display.
  10. Press "+" displays "AREA USA". Using preset key 1 to scroll through, "AREA CANADA", "AREA OC+RDS", "AREA JAPAN", "NO AREA", AREA EUROPE", and back to "AREA USA".
  11. Press "+" shows "VIEW 1". Using 1-4 keys to display "VIEW 1", "VIEW 2", "VIEW 3", "VIEW 4". Looks like brightness control for the display.
  12. Press "+" shows "AF MAN" which is adjustable with the arrow keys <|m|> to turn "AF OFF" or to "AF MAN".
  13. Press "+" returns back to serial number screen.

To get out of this maintenance mode, turn off the radio.

Note: The above is from a 99 M coupe with BMW Business CD. Display information my be different depending on radio style and manufacture.


How do I remove the head unit?

On both sides of the front plate of the head unit are little doors that swing out. Use a very small screwdriver to open the doors. A special tools that has five sides to it is used to retract a lever on both sides of the unit. Once retracted the head unit will be loose and you can pull it out. If you don't have the special tool (available from BMW), use an allen wrench or a torx bit that just fits the opening. Once removed, there are plugs on the back, antenna, wire plug, and possible additional connectors for CD changer and antenna diversity that need to be removed.


What is the wire pin-out for the indash BMW Business CD?

  1. Left-front +
  2. Right-front +
  3. Left-rear +
  4. Telephone Mute
  5. Positive, switched power
  6. Right-rear +
  7. I-bus
  8. Left-front -
  9. Continuos positive
  10. Speedometer signal for speed-dependent volume control
  11. Right-front -
  12. Left-rear -
  13. Lighting, dimmer
  14. Right-rear -
  15. Ground
  16. Remote Power-on, antenna or power amplifier
  17. not assigned


Where is the amp located in a M coupe or Z3 coupe?

It is located on a shelf above the location for the CD-Changer, in the area behind the passenger seat.


What is the wire pin-out for the HK Amp?

Connector J1, 12-pins
Pin Function Wire Color
1 12V red/white
2 On/Off white
3 Ground brown
4 Ground brown
5 RR LO + blue/purple
6 RR LO - blue/gray
7 LF LO + yellow/red
8 LF LO - yellow/brown
9 RF LO + blue/red
10 RF LO - blue/brown
11 LR LO + yellow/gray
12 LR LO - yellow/blue

Connector J2, 26-pins
Pin Function Wire Color
1 RR - IN blue/gray
2 RR + IN blue/purple
3 LR + IN blue/black
4 LR - IN yellow/brown
5 N/C N/C
6 N/C N/C
7 N/C N/C
8 RF HI + yellow/red, midrange
9 RF HI - brown/orange, midrange
10 LR HI + yellow
11 LR HI - brown
12 RR HI + blue
13 RR HI - brown
14 RF - IN blue/brown
15 RF + IN brown/black
16 LF + IN yellow/red
17 LF - IN yellow/brown
18 N/C N/C
19 N/C N/C
20 N/C N/C
21 LF HI + yellow/green, tweeter
22 LF HI - yellow/brown, tweeter
23 RF HI + blue/brown, tweeter
24 RF HI - blue/green, tweeter
25 LF HI + yellow/blue, midrange
26 LF HI - yellow/gray, midrange

Connector J3, 6-pins
Pin Function Wire Color
1 GAL IN black/white
2 SPATIAL N/C
3 SUB LO N/C
4 GAL OUT N/C
5 SUB OW N/C
6 SUB HI N/C


What are the part numbers for the H/K system?

65-13-8-400-255 subwoofer 2x2ohms 32w
65-12-8-400-292 amp H/K N6946.Kf E36/7C


Why does the factory alarm not activate and chirps three times, after having replaced my factory radio with an aftermarket?

3 chirps means that one of the alarm circuits is open. There is a thick gray plastic pin on the back of the original BMW head unit. This pin engages in a "socket" in the dash when the head unit is installed. There is a sensor in the socket that detects the presence of the pin. If the alarm is armed and the pin (radio) is removed the alarm will sound. The other side to this is that the alarm will not arm if the pin is not engaged. The pin unscrews from the back of the BMW radio. You should be able to figure out how to attach it to your new head unit or this "socket" needs to be tripped by your installer so the alarm system thinks that the radio is installed.



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