TC2 to TC1 steering wheel retrofit swap install with wiring audio controls

TC2 carbon fiber steering wheel with Black Cat Custom gauge face

Introduction

This article describes what you need to retrofit a TC2 steering wheel onto your TC1. 

Parts used

  • TC1 clock spring (already in your car)
  • TC2 steering wheel
  • TC2 airbag

2005 Scion TC does not have audio controls on the steering wheel

If you own a 2005 Scion TC, your car did not come with Audio controls. You will not be able to wire up the audio controls on the TC2 steering wheel.  In theory if you want to add it, you would need a (2006-2010) TC1 clock spring, and the harness that would normally go to the stereo from there. I don’t have any more info on this.

My 2006-2010 TC steering wheel has audio controls and an aftermarket head unit

If you have a 2006-2010 TC AND an aftermarket head unit, you’ll need to make sure that works, first. In otherwords, some aftermarket radios do not automatically work with stock steering wheel controls. You need some type of adapter or interface. For example, I have a Pioneer AVH-210EX head unit. I used this Metra Axxess control interface to get my stock TC1 steering wheel to control the head unit.

My 2006-2010 TC steering wheel has a audio controls and a stock head unit

You’re good to go, continue reading.

Does the spline fit or is there an adapter needed

The TC2 and TC1 splines are exactly alike, you can just pop and swap the TC2 wheel onto your TC1. Make sure to align your wheels straight before putting on the TC2 wheel.

Does the cruise control still work?

The harness from the TC2 to the TC1 clock spring is a direct fit. The cruise control stalk works as designed.

Does the airbag need any modification?

No, the airbag wires are also a direct connection (harness and everything). Red goes to red. Black goes to black. Oh yeah, make sure your battery is unplugged first, duh.

Does the horn need any modification?

No, the horn ground is a direct plug in. If you need to, pinch the ears on the spade so that they are tight when you plug the horn wire in the back of the TC2 airbag.

How do I wire the audio controls?

OK, here’s the info you’ve been waiting for. You have two ends here

  • TC2 steering wheel audio button control – 3 wires
  • TC1 clock spring (receiving end) – 4 wires
Scion tc2 to tc1 steering wheel retrofit wiring audio controls
LEFT – TC2 three wires.   RIGHT – TC1 four wires.

 

TC2 to TC1 steering wheel retrofit how to wire the audio controls
TC2 to TC1 steering wheel retrofit how to wire the audio controls
TC1 clock spring harness has 4 wires because one of those wires controls illumination. The TC2 audio control buttons DO NOT have illumination. So we will not use this 4th wire.
Clip the harness sockets and leave yourself as much slack as you can. You will only be splicing/soldering 3 wires together. Do yourself a favor and solder these connections so you don’t have to go back in there again. Scroll down for links to my soldering tools.
 

Here’s the wiring:

  • TC2 green to TC1 grey
  • TC2 brown to TC1 brown
  • TC2 black to TC1 white with silver
  • The TC1 white with red stripe is NOT used. Tape and tuck it away where it won’t snag

Random extra info

If you are looking for the steering wheel caps (on the back side) here are the OEM part numbers:
  • right Steering Wheel Cap – Toyota (45186-21010-C0)
  • left Steering Wheel Cap – Toyota (45187-21010-C0)
need switch covers for the back of the TC2 steering wheel cover
need switch covers for the back of the TC2 steering wheel cover

 

Scion TC2 rear steering wheel covers 45186-21010-C0 and 45187-21010-C0
Scion TC2 rear steering wheel covers 45186-21010-C0 and 45187-21010-C0

TC2 rear covers for the steering wheel
TC2 rear covers for the steering wheel

Links to soldering tools and accessories


 

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