CTSHO005.2 Honda Steering Wheel Stalk Control Adaptor

This is another adapter example that you may need to connect aftermarket audio to wheel buttons and some more signals (dash light, reverse, parking brake, etc).

Link to http://www.ebay.com/itm/370765327954 - 39 GBP + 12 GBP (delivery).

This is a patch lead, PDF is here.

In default configuration it works as follows: it outputs resistance change depends on button pressed.
These are readings on KEY1 wire

Idle (nothing pressed)	11.5 MOhm 189 kOhm (after 1st time pressed)
Volume Down	22.00 kOhm
Volume Up	16.43 kOhm
Seek Backward	11.82 kOhm
Seek Forward	8.58 kOhm
Middle (circle button)	2.07 kOhm

I believe, you can change to voltage too just follow the instructions.

This is an adapter doc, PDF is here.

Wiring for Civic connectors.

Note that ACC signal is taken from 2nd connector both with CAN bus.

Let's open this sucker.

Main ICs are:
NXP TJA1040 - High speed CAN transceiver
Renesas Eelectronics R5F2123 - R8C Series 16 bit 3 kB RAM 64 kB Flash Microcontroller SMT
Fairchild FDS4953 - Dual 30V P-Channel PowerTrench MOSFET

Little man says hi!

Standby consumption.
When you first plug it, it will drain about 25-30mA for a few seconds and than falls into 3mA even when you send 12V to ACC.

The only addition I've made is adding original Honda's AUX 3 wires (on right) to it.

42,100 km | 2Y 9M