Thought I'd add my preferred method here...
I use the free Torque app on my Android phone along with any inexpensive OBD2 Bluetooth transceiver ($10-$15). The basic Torque app doesn't come with the Toyota specific code built in but you can buy the add-on or you can enter the translation...
If you are in a cold weather area you should look at the fault code explanations here:
Secondary Air Injection System Codes: Toyota & Lexus | Hewitt Tech
C1201 – Engine Control System Malfunction – VSC and TR(A)C Prohibited
P2445 – Pump Stuck OFF Bank 1 * Important cold weather note, see...
I did a similar project on my '90 4Runner a while back. The post is on YotaTech here:
https://www.yotatech.com/f116/front-seat-swap-91-4runner-completed-159939/
Like you, I sourced the factory (Audi) heat controls and installed them under the radio.
Good luck! :thumb3:
Jim G.