Basically CD70 manufactured before year 2007 do not have aux in function. To activate CD70 Aux function in these head units, you will need to:
1. Update your CD70 to latest firmware, i.e. 10/10/2007.
2. Find A Tech2 or Vauxcom or similar product to activate your aux-in in the software. A new "Aux" menu will be appeared just as shown in the picture after a successful activation. (See picture)
This will be achieve by alter Code Index from 003 to 013.
3. Open your CD70 and solder some components (which are provided by this auction) to the mainboard, this will require an AVERAGE soldering skill.
Reference part number:
RS PN: (rswww.com)
192-516 0603 SMT Ceramic Cap,X7R,200V,100pF
391-296 0805 X7R ceramic capacitor, 16V 0.47uF
547-8638 MV SMT Al electrolytic cap,16V,47uF
679-0633 CRCW0603 Resistor T/R 0.10W,1%,68K
678-9667 CRCW0603 Resistor T/R 0.10W,1%,10K
568-3592-5-ND SOIC8 TDA8579
4.7k 0603 resistor is not included.
Tips: 0.47uF caps are in 0805 footprint, 47uF caps are in case E (or whatever equvalient) footprint, any other parts are in 0603 footprint.
The component location and reference schematic are in attachment.
Schematic is here:
4. Connect 3 wires to the back socket of unit, and possibly you could buy a 3.5mm stereo socket. Use PIN 24, PIN 25 as left and right, and Use PIN 18 as ground of audio input. (DO NOT GROUND THIS PIN TO VEHICLE GROUND, ALTHOUGH IT'S NOT HARM FOR DOING SO.)
Again, you take all risks for these modification... and AVERAGE DIY and soldering skill is needed. I finish all this with just a soldering iron.