Just thought I'd share with you a little project I embarked on recently. My existing steering wheel was a little worn on the leather grips and my initial intention was to either change to a similar steering wheel, or upgrade to the facelifted 3GS version.
Before. Worn leather and didn't feel sporty enuf lol
Then my curiosity got the better of me. I started looking at the possibility of retrofitting an ISX50 steering and noticed from multiple eBay pictures that it would fit as the back bezel was similar to ours. I was however unsure whether the buttons would work. I also wanted to take advantage of the ISX50 paddle shifters if it would work with the 3GS tiptronic if only it would work.
And so luck has it, I stumbled upon a wrecked ISF and purchased the steering wheel plus a normal IS250 airbag cover & ignitor together for this retrofit.
Upon inspection comparing our 3GS steering wheel vs the ISF I noticed the following:
1. Airbag ignitor is similar size and has similar Dual stage connectors
2. Cruise control stick has similar wiring and adapters that connect to the clockspring
3. Buttons on both steering wheels were similar in terms of functions with exception my car never had the voice command
4. Paddle shifter wiring was integrated into a similar adaptor that plugged into the clockspring
And so came the retrofit. Pretty much did the following to get everything working with the help of an engineer friend. We removed the old steering wheel and replaced it with the ISF wheel. All the adapters from the ISF steering matched up to the originals and plugged in straight up. On 1st test, all buttons were working fine, mode, volume, next track, back track, phone on/off hook, cruise control and even radar distance and horn. Was very pleased that it was so easy! The only thing that didn't work were the paddle shifters. Expected! The 3GS never had paddle shifters from factory.
With the help of a friend, we went further into tracing the wires on the steering wheel that controlled the upshift and downshift, subsequently we opened up the gear shifter section and found wires for the tip tronic upshift and downshift. Tapped the wires from there and the paddle shifts now work! Should've seen the look on our faces
Here are some pics for a start. More pics to follow soon. So happy with this mod. I'm located in Australia btw
EDITED: INCLUDED DIY GUIDE.
Before your begin, the usual disclaimers apply here for any sort of DIY job
I don't have to mention it. I'm just providing the steps i took for my own car and may or may not apply to yours. Hence it's always important to check first.
A. FINDING THE RIGHT STEERING WHEEL
It's important to find a replacement steering wheel that has almost identical functions are your stock steering wheel. Hence the ISF had most of the functions
B. MAKE SURE IT FITS
Make sure it fits by comparing the design of the bezel before you purchase it. I made a mistake of purchasing an ES300 steering wheel once. It didn't fit
C. COMPARE THE AIRBAGS
Make sure the Air bag ignitor connectors are identical. The 3GS came with 2 stage ignitors and you should use similar. I bought an IS250 airbag cover and ignitor to match the ISF Steering wheel which already had a blown airbag
D. BEGIN THE DIY - REMOVE THE STEERING WHEEL
Follow this DIY if you're unsure how to remove the Steering Wheel Link below:
E. COMPARE THE STEERING CABLE ADAPTORS (GS VS ISF)
On the ISF adaptor, the Pink and Orange wires are used for the Paddle Shifters. Compare these with your GS Adaptor. For mine, i had an unused slot and another Yellow Black wire which we ascertained was a wire that was standby/ never used. Good news! We had ample slots to use!
F. CHECKING THE CLOCKSPRING PINS
We took note of the PINS that were for Downshift and Upshift that corresponded with the ISF Adaptors (Pink - Downshift) and (Orange - Upshift)
G. REMOVE THE STEERING COLUMN COVER
Remove 3 screws to reveal the wires underneath that correspond to the Clock Spring PINS
H. TEST AND CONNECT TWO WIRES (UPSHIFT/DOWNSHIFT) TO THE ADAPTOR.
Find the corresponding slot on the adaptor by using a multi-meter and test for continuity from ClockSpring to this adaptor. We found both the UpShift and DownShift PINS. Subsequently run wires from here to the GearShift adaptor to tap the UpShift/DownShift signal there.
I. REMOVE CENTRE GEARSHIFT COVERS
Remove the covers above the GearShifter. Once you've done it locate the White Bundled wire. The UpShift/Downshift cables are inside it.
J. FIND THE UPSHIFT/DOWNSHIFT CABLES
It tries to play hide n seek but you will find it.
K. CONNECT RETROFIT CABLE TO THE UPSHIFT/DOWNSHIFT SIGNALS
It's quite hard to get this adaptor out as it's snapped in place underneath. Give it a good tug.
L. RUN THE WIRES AWAY FROM SIGHT
Run the wires behind the firewalls so that it looks the part. Use cable ties etc
M. PUT EVERYTHING BACK IN REVERSE ORDER
Job done and enjoy. Couldn't have done this without my Engineer friend help!