20-pin + 8-pin to 28-pin Toyota Head Unit Transplant Harness with AM/FM Adapter (Replaces Toyota PT546-00120-CH)

Item Number: AHH-2028

Put a newer Toyota or Scion factory radio in an older Toyota. Toyota head units from about 2013 on use one 28-pin plug for the steering wheel buttons, AUX input, hands-free microphone, vehicle speed and reverse signals. Older Toyota and Scion vehicles carry those signals on a 20-pin plug instead, with the factory hands-free microphone on a separate 8-pin plug. When you swap in the newer radio, the power and speaker plugs connect, but the steering wheel controls, microphone and AUX port stop working. This adapter fixes that: the car's 20-pin and 8-pin plugs connect to one end, and the 28-pin plug on the other end goes into the back of the new radio.

Replacement for the discontinued Toyota PT546-00120-CH. Toyota's own 28-pin to 20-pin + 8-pin conversion harness (part number PT546-00120-CH, also written PT546-00120CH) is no longer available from dealers. We build a plug-and-play replacement with factory-style connectors on both ends, so nothing in the car gets cut, spliced or soldered.

What it keeps working:
-Steering wheel audio buttons (volume, seek/track, mode)
-Factory hands-free microphone for Bluetooth calls (8-pin plug)
-AUX input in the console
-Vehicle speed signal
-Reverse signal for a backup camera (labeled wire lead, see below)

AM/FM antenna adapter included. The newer radios have a different antenna jack than the plug in the older vehicles, so the kit includes the antenna adapter.

USB cable: optional, +$20. The newer radios take USB through a connector on the back of the unit, and the USB port in an older car usually can't be connected to it. Choose the USB cable option to get a cable with a standard USB port on one end and the plug for the back of the new radio on the other.

Toyota part numbers from swaps we have built this adapter for:
-Toyota PT546-00120-CH 28-pin to 20-pin + 8-pin conversion harness (this adapter replaces it)
-2012 Tacoma: original radio 86120-04260 (face ID A518B3) upgraded to the 2014 Tacoma touchscreen radio 86140-04090 (face ID 57054)
-2010 4Runner (radio ID 11853) upgraded to a 2016 4Runner radio (ID 510142)
-Scion head units: Pioneer T1819 (2012 Scion iQ), T10015 (2004 4Runner), PT546-00140 (Scion xB)
-2009 Toyota Avensis T27 (UK): 86120-05150 to 86140-05010
-2011 Toyota Verso (Europe): 86120-0F090 to 86140-0F010
The 8-pin microphone plug is the same connector used by the Toyota PT546-74120-MC hands-free microphone kit.

Before you order:
-Both radios must be non-JBL. JBL systems use an external amplifier and are wired differently. Email us about JBL swaps.
-This adapter is for installing a Toyota or Scion factory radio. For aftermarket radios (Pioneer, Sony, Kenwood, ATOTO), see our direct wire harnesses instead.
-On most of these vehicles, the 10-pin and 6-pin power and speaker plugs connect straight to the newer radio. If yours don't, email us before ordering.
-Factory navigation, SiriusXM and GPS antenna connections are not part of this kit. Ask us if you need them.
-The older 20-pin vehicles don't carry a reverse signal at the radio, so the adapter has a labeled reverse signal wire. Connect it to the reverse light circuit if you are adding a backup camera. Otherwise, tape it off.
-Phone menus and some settings on the newer radios are limited while the vehicle is moving. That is normal Toyota behavior, driven by the vehicle speed signal.

Built to order. Each adapter is built for your vehicle and radio and usually ships in about a week. At checkout, please tell us your vehicle year/model, the part number of the radio you are installing (on the label on the radio's case, usually 86140-xxxxx), and whether the car has the factory hands-free microphone. Questions? Email us.

What's included:

-One 20-pin to 28-pin conversion harness, the replacement for Toyota PT546-00120-CH, with labeled reverse signal and ground leads. It includes the 8-pin hands-free microphone plug when your car has the factory microphone.
-One AM/FM antenna adapter
-USB cable, only if you choose the USB option (+$20)

Not included: the head unit, dash trim, microphone, backup camera, or GPS/SiriusXM antennas.

Installation:

1. Confirm both radios are non-JBL and note the new radio's part number.
2. Remove the old radio and unplug all of its connectors.
3. Plug the vehicle's 10-pin and 6-pin power/speaker connectors into the new radio.
4. Plug the car's 20-pin connector (and the 8-pin microphone connector, if your car has one) into the adapter, and plug the adapter's 28-pin connector into the back of the new radio.
5. Plug the car's antenna cable into the AM/FM adapter, and plug the adapter into the radio's antenna jack.
6. Bolt the labeled ground wire's ring terminal to a bare-metal ground behind the dash. If you are adding a backup camera, connect the labeled reverse signal wire to the reverse light circuit. Otherwise, tape it off.
7. If you ordered the USB cable, plug it into the USB jack on the back of the radio and route the port to where you want it.
8. Test the steering wheel buttons, a Bluetooth call, AUX and the radio before you put the dash back together.

Need help with your install? Email us at inquiry@autoharnesshouse.com.

Purchase:

Price: $100.00

Vehicle Fitment:

(If a known model is not listed, let us know)

Fits Toyota and Scion vehicles with the older 20-pin radio plug (usually with a separate 8-pin hands-free microphone plug) when you install a newer, non-JBL Toyota or Scion factory radio with the 28-pin plug. Swaps we have built this adapter for:

2005-2012 Toyota Tacoma (with a 2013-2015 Tacoma radio)
2001-2013 Toyota 4Runner (with a 2014-2019 4Runner radio or a Scion radio)
2006-2011 Toyota RAV4 (with a 2012+ RAV4 radio)
2008-2011 Scion xB
Scion xD (20-pin models)
2012 Scion iQ (20-pin models, with the Scion/Pioneer T1819)
2009+ Toyota Avensis T27 (UK/Europe)
2011 Toyota Verso (Europe)

Check your plug on a 2013 4Runner or a 2012-2013 Tacoma. Toyota built some of these trucks with the older 20-pin plug and some with the newer 28-pin plug. If yours already has the 28-pin plug, the newer radio plugs in directly and you do not need this adapter.

Not sure which plug your car has? Send us a photo of the connectors behind your radio and the part numbers of both radios, and we will confirm.