T27 head unit replacement, connectors

[Sp000ny]

I've upgraded from a T25 to a T27 (2011), I already had a Pioneer Android Auto head unit in the T25 with a steering wheel control adapter which I'm putting in the T27, it seems to share the same 3 big white connectors so I'm assuming it will work. I have a couple of unknown connectors in the T27 to identify and some adapters to source.

Question 1, what is the model number of the OE head unit please?

Question 2, what does plug A do?

Question 3, plug B appear to be the FM radio aerial, where can I get an adapter to convert this to a regular old fashioned long thin plug?  Does plug B only provide FM aerial, or something else too?

Question 3, plug C appears to be the reversing camera, where can I get an adapter to convert this to a standard RCA type plug? I'm hoping to retain the original reversing camera.

Thanks

[Sp000ny]

OK I will answer my own questions for future reference, as I've now successfully installed my Pioneer Android Auto double DIN head unit and I have retained use of the steering wheel controls AND the original reversing camera.  This has been quite a learning journey. Maybe this will help someone else in the future.

Connector A in my picture above, I believe to be the GPS aerial input to the toyota navigation head unit, therefore not required for an aftermarket android head unit.

Connector B is the FM aerial, this can be converted to an old fashioned aerial which only seems to use one of the 2 pins, so maybe it also provides DAB signal but this is just a guess. I've chosen not to install an aftermarket DAB aerial just yet, as I've only had poor experiences with them in the past.

Connector C is 12v in the red wire when in reverse gear, the yellow wire shows around 4.6v when in acc or ign, and possibly related to the power supplied to the reversing camera.

This is where it gets complicated, there is a 20 pin connector visible in my second picture above, mine has 13 pins connected and I've deduced what most of them do (a combination of inputs and outputs); reversing camera, steering wheel controls, microphone, I suspect my 7 empty pins would be used for things I don't have such as USB and aux input.  I already have a wiring harness from my previous T25 that retains the use of the steering wheel controls, this connects to the 20 pin connector but only uses 3 of them.  

Then I have sourced a separate harness/adapter from eBay that retains the use of the reversing camera, however this also needs to be plugged into the same 20 pin connector and uses 4 different pins, so I can either have the steering wheel controls OR the OE reversing camera! To make matters worse, the 4 pins in camera harness do not correspond with the correct pins in my 20 pin connector, so I'm not 100% sure at this stage what wires I need to connect them to.

The solution to this is to purchase some empty 20 pin connectors from Aliexpress, male and female, complete with lots of pins, buy a crimping tool from Amazon, and create my own harness that plugs into the 20 pin connector, but outputs to 2 male plugs, one for steering wheel controls, and one for the camera.  The SWC one was easy as I had a working harness to copy the wiring, but for the camera I had to scour the internet for information to identify which wires do what. 

The camera harness I got from eBay takes a 12v input and converts to 6v, which then connects to the 20 pin harness so this confirms the camera runs on 6v, also the camera doesn't actually require any signal that the car is in reverse, its always on when the car is on, only the head unit requires the reverse gear signal to switch to camera mode.

I've attached my pin layout to show what each does. Pins 1 (red) and 11 (white) are the video signal from the camera, these go to the RCA plug.  Pin 3 (black) is the 6v power to the camera, 12 (orange) is the camera ground.  Pins 6 7 and 8 are for the steering wheel controls.  Pins 13, 14 and 20 I am not sure about, but I did not need.

I hope this helps someone one day, one thing I will say is that I believe different spec cars and different age cars appear to have different pin layouts in the 20 pin connector and I wouldn't even go as far as to assume the wire colours are the same, so a volt meter is required to measure voltages and find grounds etc.

[flash22]

you are correct

A. GPS (HRS GT-5)

B. FM aerial

C. 5 pin rev, hand brake and VSS (speed)

reverse cam and audio controls are on the 20-pin

 

Edit. the factory radio is a dealer fit option (part number starts with PZ) - It's a TNS510

[mekanieker]

The original Toyota camera works on 5 volts, I installed an Android radio myself and still use the original camera with a separate power supply of 5 volts DC.

[Konrad C]

Well done at solving your head unit installation. There have been posts on this subject in the past - 

I am doing other things so not always on this site. Toyota are fairly consistent when it comes to head unit connections, because a unit fitted to T22 or T25 uses the same basic connecters. It's just the accessories that can be an issue. I have have the basic CD/radio in my T27 and use a Bluetooth/USB adapter via the CD changer port. Originally, the adapters were for the T25, but work perfectly with the newer model. That is why you can move your head unit from your previous car to the later model. Anyway, enjoy your installation and I am sure someone will use your shared experience. 

[mekanieker]

On 2/3/2024 at 12:38 PM, Sp000ny said:

OK I will answer my own questions for future reference, as I've now successfully installed my Pioneer Android Auto double DIN head unit and I have retained use of the steering wheel controls AND the original reversing camera.  This has been quite a learning journey. Maybe this will help someone else in the future.

Connector A in my picture above, I believe to be the GPS aerial input to the toyota navigation head unit, therefore not required for an aftermarket android head unit.

Connector B is the FM aerial, this can be converted to an old fashioned aerial which only seems to use one of the 2 pins, so maybe it also provides DAB signal but this is just a guess. I've chosen not to install an aftermarket DAB aerial just yet, as I've only had poor experiences with them in the past.

Connector C is 12v in the red wire when in reverse gear, the yellow wire shows around 4.6v when in acc or ign, and possibly related to the power supplied to the reversing camera.

This is where it gets complicated, there is a 20 pin connector visible in my second picture above, mine has 13 pins connected and I've deduced what most of them do (a combination of inputs and outputs); reversing camera, steering wheel controls, microphone, I suspect my 7 empty pins would be used for things I don't have such as USB and aux input.  I already have a wiring harness from my previous T25 that retains the use of the steering wheel controls, this connects to the 20 pin connector but only uses 3 of them.  

Then I have sourced a separate harness/adapter from ebay that retains the use of the reversing camera, however this also needs to be plugged into the same 20 pin connector and uses 4 different pins, so I can either have the steering wheel controls OR the OE reversing camera! To make matters worse, the 4 pins in camera harness do not correspond with the correct pins in my 20 pin connector, so I'm not 100% sure at this stage what wires I need to connect them to.

The solution to this is to purchase some empty 20 pin connectors from Aliexpress, male and female, complete with lots of pins, buy a crimping tool from Amazon, and create my own harness that plugs into the 20 pin connector, but outputs to 2 male plugs, one for steering wheel controls, and one for the camera.  The SWC one was easy as I had a working harness to copy the wiring, but for the camera I had to scour the internet for information to identify which wires do what. 

The camera harness I got from ebay takes a 12v input and converts to 6v, which then connects to the 20 pin harness so this confirms the camera runs on 6v, also the camera doesn't actually require any signal that the car is in reverse, its always on when the car is on, only the head unit requires the reverse gear signal to switch to camera mode.

I've attached my pin layout to show what each does. Pins 1 (red) and 11 (white) are the video signal from the camera, these go to the RCA plug.  Pin 3 (black) is the 6v power to the camera, 12 (orange) is the camera ground.  Pins 6 7 and 8 are for the steering wheel controls.  Pins 13, 14 and 20 I am not sure about, but I did not need.

I hope this helps someone one day, one thing I will say is that I believe different spec cars and different age cars appear to have different pin layouts in the 20 pin connector and I wouldn't even go as far as to assume the wire colours are the same, so a volt meter is required to measure voltages and find grounds etc.

recently installed camera Toyota 2015 on an Android radio black +5.2 volts, white -, red + video signal, orange - mass video signal

[YoungChi]

I am looking for the 20 Pin Reverse Camera Retention Adapter For Toyata Avensis T27 2011.

how did you solve the steering wheels issue with the 20pin adapter?

[2009joe]

On 2/3/2024 at 11:38 AM, Sp000ny said:

OK I will answer my own questions for future reference, as I've now successfully installed my Pioneer Android Auto double DIN head unit and I have retained use of the steering wheel controls AND the original reversing camera.  This has been quite a learning journey. Maybe this will help someone else in the future.

Connector A in my picture above, I believe to be the GPS aerial input to the toyota navigation head unit, therefore not required for an aftermarket android head unit.

Connector B is the FM aerial, this can be converted to an old fashioned aerial which only seems to use one of the 2 pins, so maybe it also provides DAB signal but this is just a guess. I've chosen not to install an aftermarket DAB aerial just yet, as I've only had poor experiences with them in the past.

Connector C is 12v in the red wire when in reverse gear, the yellow wire shows around 4.6v when in acc or ign, and possibly related to the power supplied to the reversing camera.

This is where it gets complicated, there is a 20 pin connector visible in my second picture above, mine has 13 pins connected and I've deduced what most of them do (a combination of inputs and outputs); reversing camera, steering wheel controls, microphone, I suspect my 7 empty pins would be used for things I don't have such as USB and aux input.  I already have a wiring harness from my previous T25 that retains the use of the steering wheel controls, this connects to the 20 pin connector but only uses 3 of them.  

Then I have sourced a separate harness/adapter from ebay that retains the use of the reversing camera, however this also needs to be plugged into the same 20 pin connector and uses 4 different pins, so I can either have the steering wheel controls OR the OE reversing camera! To make matters worse, the 4 pins in camera harness do not correspond with the correct pins in my 20 pin connector, so I'm not 100% sure at this stage what wires I need to connect them to.

The solution to this is to purchase some empty 20 pin connectors from Aliexpress, male and female, complete with lots of pins, buy a crimping tool from Amazon, and create my own harness that plugs into the 20 pin connector, but outputs to 2 male plugs, one for steering wheel controls, and one for the camera.  The SWC one was easy as I had a working harness to copy the wiring, but for the camera I had to scour the internet for information to identify which wires do what. 

The camera harness I got from ebay takes a 12v input and converts to 6v, which then connects to the 20 pin harness so this confirms the camera runs on 6v, also the camera doesn't actually require any signal that the car is in reverse, its always on when the car is on, only the head unit requires the reverse gear signal to switch to camera mode.

I've attached my pin layout to show what each does. Pins 1 (red) and 11 (white) are the video signal from the camera, these go to the RCA plug.  Pin 3 (black) is the 6v power to the camera, 12 (orange) is the camera ground.  Pins 6 7 and 8 are for the steering wheel controls.  Pins 13, 14 and 20 I am not sure about, but I did not need.

I hope this helps someone one day, one thing I will say is that I believe different spec cars and different age cars appear to have different pin layouts in the 20 pin connector and I wouldn't even go as far as to assume the wire colours are the same, so a volt meter is required to measure voltages and find grounds etc.

what pioneer outo system did you put in and in my 2014 avensis with the touch 2 system i love my dab+ on it  the signal is great and tbh i mostly listen to the dab+  when you say you have a  bad experience with dab in the past was it through the pioneer auto system or your older stock toyota headunit