Setup of Sony Ericsson HCA-60 in a SAAB 9-5 AS2  Last update 5-Nov-2006

This has been tested with the Pioneer FX-M2016ZSA X1B/EW version of the 9-5 AS2 Stereo,
but is believed to apply to all Pioneer AS2/AS3 stereos mounted in 9-5 Model Year 1998-2005.

This guide assumes that the car is equipped with the integrated handsfree microphone included in
the "Tel 1" option, set to high level (active) output and that the Adapter cable 400 108 130
(MY1998-2000) or 400 129 086 (MY2001-2002) is fitted. The Adapter cable should be
connected black to black (Ground), red to red (Battery), yellow to yellow (Radio Mute) and
maybe blue to blue (Ignition Sense): the blue cable is only needed if the alarm on Ignition Sense
alarm function is to be used. For microphone connections, see below.

There are a few problems here:

1) The microphone level is too low for the HCA-60.

2) The HCA-60 sometimes passes trough glitches from the telephone which makes the AS2
    switch in and out of telephone mode in an unpredictable and annoying way.

3) The AS2 doesn't have Stereo telephone input.

Solution for microphone level being too low for the HCA-60.

This can be solved by adding a simple buffer between the 9-5 microphone and the HCA-60. This
buffer is also useful for improving the level of the HCA-60 original microphone. This buffer circuit
relies on the fact that the output impedance of the microphone is several times higher than the input
impedance of the HCA-60, and with this buffer the microphone load becomes much less. The
microphone input on the HCA-60 supplies about 5V active voltage (with a short circuit current
of 10mA) to the 9-5 microphone, and as this circuit consumes about 0.5mA it doesn't have any
major impacts on these levels. This will boost the microphone level about 10dB, which seems
to be just what is needed:

Connect the 9-5 microphone lead (brown/grey) to microphone input, and the microphone return
(green) to mic ground. In some cars, that have had been wired for some handsfree versions, the
microphone input may show up at the wrong pin, pin 9, in the car connector. If the microphone
doesn't work, check that the microphone in the roof has pins 1 (High Level Input) and 3 (Ground)
connected to the cable, and then that the microphone cable is connected to pin 10 in the car
connector mating Adapter cable 400 108 130.

Connect the microphone out to HCA-60 pin 1 and microphone ground to HCA-60 pin 2.

HCA-60 Microphone connector (Micro Mate-n-loc/Micro-Fit 3.0, tin plated):

       +---+                    +---+
       | 1 |  High level input  | 1 |
       +---+|                  |+---+
       | 2 ||      Ground      || 2 |
       +---+|                  |+---+
       | 3 |                    | 3 |
       +---+                    +---+

Socket bottom view    Microphone connector view on HCA-60

Suitable wire connectors are either AMP Micro MATE-N-LOK, product number 0-1445022-3
with crimp sockets 0-0794610-1, or Molex Micro-Fit 3.0, product number 43645-0300 with
crimp sockets 43030-0007.

Solution for switching in and out of telephone mode

This can be solved by adding a simple damper over the Radio Mute input. This circuit will not slow
down entering Radio Mute mode (due to the resistor) but will delay exiting with about 2 seconds:

The Radio Mute input has an Off mode voltage of about 4 V, and consumes about 1mA of current
when grounded by the HCA-60 in the On mode.

Connecting the HCA-60 stereo output to the AS2

This is an alternate solution to using the HCE-26 Stereo Mute box, which means that the AS2
volume and tone controls, as well as all speakers, are used when the telephone input is used. As a
note, the HCE-26 uses gold plated connectors, but as the HCA-60 has tin plated pins, standard
tin plated connectors should be used to avoid corrosion.

The signal is feed to the resistors R403 and R404 instead of the Tel In signal which are feed using
an isolation transformer, as shown below. A connector in between is highly recommended, and the
description assumes that a MiniDIN6 is used. These connectors, which are gold plated, are used
on PS/2 keyboards and mice, and are readily available.

A panel mount connector with metal casing can be soldered to the removable upper rear plate
of the AS2. To simplify wiring, a cable piece from a cheap or broken PS/2 mouse can be
used. As the transformer should have a damping of at least 20dB, if Biltema 31-454 is used
(, both internal 22 ohm resistors
should to be replaced with 10 ohm resistors.

AS-2 connections:

Transformer cable wiring (new components added as shown):

Full 9-5 AS2 to HCA-60 wiring list:

Solder point AS2 MiniDIN6 Cap Transform Res HCA-60
Left in: R403 pin 1   OutL : InL+   Pin 5
    InL- Pin 6
Common: R403+R404 pin 4 o
+ | +
22u | 50V
    InR- Pin 8
Right in: R404 pin 5 OutR : InR+ Pin 7
Ground (from screw) pin 3
HCA-60 Mute       o
Pin 2
Resistor for
presence detect
HCA-60 +12V Pin 3

MiniDIN 6-way connector:

Pin 1 Left channel,  Brown wire (Data) on MS original PS/2 mouse
Pin 2 No connection
Pin 3 Ground,        Red wire (Ground) on MS original PS/2 mouse
Pin 4 Common,        Orange wire (Vcc) on MS original PS/2 mouse
Pin 5 Right channel, Yellow wire (Clk) on MS original PS/2 mouse
Pin 6 No connection

HCA-60 Stereo Mute Box connector (Micro Mate-n-loc/Micro-Fit 3.0, tin plated):

           +---+---+           +---+---+
    Ground | 1 | 5 |   Left +  | 5 | 1 | Ground
           +---+---+           +---+---+
Radio Mute | 2 | 6 ||  Left - || 6 | 2 | Radio Mute
           +---+---+|         |+---+---+
      +12V | 3 | 7 || Right + || 7 | 3 | +12V
           +---+---+           +---+---+
           |XXX| 8 |  Right -  | 8 |XXX|
           +---+---+           +---+---+

  Socket bottom view    Stereo Mute Box connector view on HCA-60

Suitable wire connectors are either AMP Micro MATE-N-LOK, product number 0-0794617-8
with crimp sockets 0-0794610-1, or Molex Micro-Fit 3.0, product number 43025-0800 with
crimp sockets 43030-0007.

For a good description of how to disassemble the AS2 unit, see the SAAB 95 MP3 player site.

Picture of wiring inside AS2:

Placement of MiniDIN 6 onnector on rear panel:

Transformer cable:

Copyright 2006 Dan Norstedt. This work is licensed under a
Creative Commons Commons Attribution-ShareAlike 2.5 Sweden License.