====== Toyota Yaris 2006 Car Radio ======

  - Pull the two side bands, starting from the bottom edge.
  - Remove the four screws.
  - Unlock the three interlocking snap in at the top: push the tabs with your finger while you pull the frame.
  - Pull the radio block, releasing the four mounting pin-push (pink color).
  - Release the three connectors and the antenna plug.

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===== Steering wheel commands =====

There are five buttons at the steering wheel: **volume +**, **volume -**, **channel up**, **channel down** and **mode**. At the radio side there are only **three wires** connected to the **20 pin connector**.

Here it is the schematic:

{{.:yaris:yaris-steering-commands-schematic.png?direct&480|Toyota Yairs steering wheel commands: schematic}}
{{.:yaris:yaris-steering-commands-wires-pinout.png?direct&200|Toyota Yairs steering wheel commands: radio connector pinout}}

With a multimeter we read the resistance values at the radio receiver connector while pressing each button:


^ Resistance at SWG - SW1  ^^
| No buttons pressed  |  100 kΩ |
| Seek +              |     0 Ω |
| Seek -              |   329 Ω |
| Vol +               |  1000 Ω |
| Vol -               |  3110 Ω |

^ Resistance at SWG - SW2  ^^
| No buttons pressed |  100 kΩ |
| Mode               |     0 Ω |

so we calculated the resistor values:

^  Steering Wheel Commands Resistors  ^^
| R1  |  100 kΩ |
| R2  |  100 kΩ |
| R3  |   330 Ω |
| R4  |   680 Ω |
| R5  |  2200 Ω |