jello2594

Hey there.. I've got all the parts for the handsfree car kit for my Sony Ericsson P910i cellphone. The HCC-20 system cable, the HCH-37 holder, the HCA-20 handsfree kit, and the HCE-16 Advanced Mute (on the way).. Will the advanced mute work on my Euro Comand (from MBenzNL) through my Bose system? I know that the plugs on the HCE-16 will fit on the back of the radio, but does anyone know if it will route the speaker from the phone calls through my car stereo and mute the audio? Any help would be so greatly appreciated.

Thanks

jello2594

OK, I pulled out my COMAND, and since I have the Bose amplifier, there are no wires in the "B" connector that the HCA-19's speaker-in and speaker-out goes to. I can probably put this module right by the Bose amplifier in the trunk, but that amp, I think, has just one big wire connector. I'll need to seperate out the speaker wires. Anybody got a wiring diagram for the Bose amplifier? I need the speaker outs for left front, right front, left rear, and right rear speakers. Thanks so much.

jello2594

Anyone got a wiring diagram for my Bose amp? I also found the "mute" wire for the COMAND also pauses the CDs while youre on the phone.. thats a nice little feature.

hadam

Did you finish installing HCA 20?

I am installing HCA 20 in my 1997 E420 W210. I got the mute figure out and got all other wiring except where to tap into speakers.

I don't want to use Sony Ericsson HCA 20 bulky speaker, I rather use car speakers to hear phone calls.

Do you know how to do it ?

jello2594

The HCA-19 is still sitting in my trunk.. I'm using the HCA-20's speaker, which actually isn't that bad... I haven't gotten any wiring diagram for the Bose amp in the trunk. If anyone out there can point me to the right place, I'd be grateful myself.

Thanks!

As a side-note, the mute wire off of the HCA-20 didnt mute my factory radio most times. It doesnt put out -12volts, it puts out -8volts. The small multi-pin connector that the HCA-19 hooks up has the proper mute wire on it.. Its one of the middle wires (either 3 or 4.. dont remember which), and hooking that up mutes the radio and pauses the CDs every time

hadam

I got the wiring diagram for speakers, but it is for W210 1997/98.

In 97-98 MB used 2 seperate speakers in the front for old analog phone system.

I will use these 2 speaker and feed the HCA 20 kit speaker output to these 2 speakers.

I can not trace the stock MIC in the car, so I will go ahead and install Sony MIC and run wire along the window and then steering wheel into the behind the head audio unit.

Tonight I tested the HCA 20 with HCA 20 speaker and MIC and drove the car on freeway and street and sound quality was great. No ground or buzzing sound.

I will do this weekend final installation in the car.

hadam

I finished installing Sony Ericsson HandsFree phone kit in my 1997 E-420. It work like a charm.

Finally put old analog phone and phone head unit to grave.

Now I got more room in armrest and under the radio cuby is available for storage.

It took 2 hours to remove all old junk and install new phone kit.

One thing is good about 97 W210, it has 2 seperate front speakers that was assign only for cell phone, so I connected my phone kit speaker out to in dash speaker and it sound good. The phone mute on MB Radio work great, it pause cassett, radio and CD when I am making phone calls and reciveing.

jello2594, Phone mute from Sony Ericsson HCA-20 [Yellow Wire] I tap into Radio head unit pin 3 [Yellow Wire] and it work fine. I did not see any problem.

Special thanks to MBMiller and Zam2000. You guys are great, thanks for all your help.

$49 for Sony Ericsson HCA-20 Phone kit and help from MBMiller and Zam2000. HandsFree driving very safe and Priceless!!

CalifSLK

There are 2 ways to do MUTE on your setup:

1. Directly Connect MUTE line.
This yellow line output from the HCB is active low (GND) or zero volts. Basically it is just short to GND. The minus voltage you saw on the HCB Mute output is likely due to the car GND and HCB GND were not connected. Just connect the HCB Mute output to the HU MUTE input on Connector A pin 3. This should MUTE the HU. This would work on all D2B and earlier HU with the ISO Connector A, B and C in the back. If the MUTE line is already used, such as a car phone setup, use method 2 below.

2. BOSE system only
The BOSE amplifiers are attached to the speakers and get a separate 12V line thru a relay. Find this Amp relay and add a 2nd NC (normally closed) relay to the GND side of the Amp Relay coil. Connect the GND side of the 2nd relay to the HCB Mute line, 12V side to car unswitched 12V. Take note not to disturb the 12V high current path going to the BOSE Amps. When you cut the Amp relay coil GND wire (black or brown), crimp mating connector pair so you can reconnect it later.

There are other ways to deal with this MUTE line issue even when the car has phone and TeleAid such as adding a logic gate to tap into the already connected MUTE line. Most commercially available solution handles it this way. All MOST system use a MUTE bus and just simply add the HCB MUTE output to the MUTE bus will work.

This 4 wire harness is used in many Handsfree devices such as the Nokia CK-1W and the S/E HCB-30. So changing to a different handsfree later become very easy.

Daniel

Disclaimer: All information is for reference only, writer takes no responsibility for its use.

jello2594

Um, untrue. Zero volts is an open circuit. DC voltage is either + or - if it has any electric potential. The yellow wire on the HCA-20 is -7 volts, which is enough to mute some Mercedes head units, but not others. For example, for my Euro COMAND, it did not work, but the -12v pin on the Advance Mute kit did work.

Removing the power to the Bose amp via a relay wouldn't pause the CD, either. Tapping into the wire behind the head-unit is by far the best way.

Thanks anyway, Daniel.

CalifSLK

Looks like you have done quite a bit of investigation already. I don't know why you got a negative voltage as nothing in the car uses negative voltage. Beside open circuit, GND is also at zero volts.

MUTE output from the car kits is designed to work as a logic low (binary 0) or the GND path for a 12V system such as the GND path for a relay. This is safe because 12V would damage the logic high of the various modern logic types. The older systems using TTL/HCT at 5V and the newer systems such as MOST using the LVTTL at 3.3V logic high. My MOST NTG1 system uses TTL/HCT at 5V. I just measured it in my R171 and the MOST master N93/1 (Audio GateWay) maintains the bus at a logic high of 4.3V normally. When my HCB-30 (Sony Ericsson Bluetooth Car Kit) receives a call, it pulls the bus low to zero volts (actually 0.04V) then the N93/1 turns off the speakers.

Cars with D2B and older systems, use an end to end signaling for MUTE without a bus. But the signal level are the same. It just make the addition of a 2nd MUTE request device more complicated. This is where the MIKBox and other solution become necessary. Logically speaking, a 2 input AND gate (type 78HCT08) will do the job. This logic function is: "when any inputs goes low, the output goes low".

For the MOST system, the MOST master provides a pull-up function to maintain the bus at logic high (~4.3V), when any device pulls the bus to logic low, the N93/1 turns off the audio output. It is that simple.

Modern car design frequently switch GND due to the higher cost of the semiconductor switches used to switch 12V vs switch GND. So many high current paths use GND switching instead of 12V switching. In this case I think the GND current switching capability of the Car kit MUTE line is limited.

Only some semiconductor technologies uses negative voltages such as GaAs. Their use in the car if any, are limited to within the individual boxes.

Disclaimer: All information is for reference only, writer will not take any responsibility for its use.