Installing a Pumpkin Android Car Stereo Head Unit Radio in my 2010 Audi A3

When I bought my 2010 Audi A3 (8P body style, also known as "2010 face lift") it came with the standard Audi Concert II head unit (Audi part # 8P0 035 186 S) and a dealer-installed Kufatec FISCON 36429 "Basic" Bluetooth adapter. From the outset I wasn't happy with this setup because the Bluetooth never worked properly throughout multiple phone changes (iPhone 3GS, 4, 4S, 5, etc.) and firmware updates. The volume was too loud and there seemed to be no way to lower it. Moreover, playing music over the Bluetooth sounded lousy - as if through an old crystal radio. (This is despite going back to the dealer numerous times, playing with the internal settings of the Kufatec and even using VCDS to try some internal Audi settings). When we recently moved house, our new driveway was extremely narrow, full of blind spots and required reversing in so I thought it would be time to replace the head unit with one that had a display for a reversing camera.

After doing some research on options, I decided to get a Pumpkin head unit to meet the following requirements:

• Have a stock "look and feel" that would not ruin the aesthetics of the dashboard
• Integrate with the steering wheel volume/channel/telephone controls
• Provide improved Bluetooth compared to the Kufatec unit
• Provide a screen for a reversing camera
• Be installable without lots of cutting / soldering / drilling - basically "plug and play"

The TL;DR version of this post is that I am happy with the end result and the Pumpkin head unit meets all my requirements. It was a bit of a journey to get there, so for all the gory detail, read the full post.

1. Buying the initial parts

I bought this Pumpkin item on eBay which came with a free camera and free Australian maps for the GPS. While it came with a free camera, the camera wouldn't look "stock" so I bought this camera instead which was billed as a plug-in replacement for the number plate light. According to some back and forth e-mails with the vendor, the specific camera I needed was the Model 603 which would be an exact replacement for my number plate light. I based my decision partially on an installation video on YouTube that showed how easy it was to install this camera. I also bought some CT22AU01 radio removal keys to help remove the old head unit.

Now on to the installation and some of the issues I had to resolve...

2. Installation - Head Unit

The physical installation of the head unit was a relative breeze. With the radio removal key, you just remove the old head unit, unplug the Quadlock connector and basically plug it into the harness of the Pumpkin unit. 

Now you can turn it on and try it out... but not the radio yet.

2.1 Head Unit - Radio Antenna Fix

The first problem you will encounter is that the radio won't work because the Pumpkin antenna connector is DIN but the Audi uses a "Twin Fakra" connector. You will need to buy one of these adapters to interface the Audi antenna to the Pumpkin. This is pretty easy, but I wish that Pumpkin included one in the box. The Pumpkin has an unterminated wire called "ANT" (see below) which you need to connect to the +12V wire on the Fakra connector. It's puzzling that Pumpkin didn't pre-make the harness with this wire connected since they clearly have provision for it.

Now the radio will work through the front speakers, but there will be no audio at the rear speakers...

2.2 Head Unit - Rear Speaker Fix

My car came from the factory with an amplified set of rear speakers. The wiring needs to send +12V down to the amp that is located in the rear of the vehicle. The stock Pumpkin harness does not wire up this connection. It will need to be wired up yourself. Like the antenna power wire (mentioned above) there is a remote amp power wire that is unterminated on the Pumpkin. This wire is labeled "AMP-CON" per the photo above. Essentially, you need to connect it to Pin 13 of the Quadlock connector per this diagram. Once this is done, you will have audio coming out of the rear speakers. I don't understand why Pumpkin did not wire this into the harness in the first place.

2.3 Head Unit - Battery Consumption Fix

Everything was working fine with the head unit at this point but I noticed that it would not fully power off when I pulled the ignition key out. I put the Pumpkin to "sleep" (but not OFF) by pressing the power button and by the end of the week my car battery was flat. I sent a complaint e-mail to Pumpkin and they immediately responded with a note telling me to cut this red wire. Cutting that red wire makes the Pumpkin power down when the ignition key is switched off. This fixed the battery problem. 

At this point, the Pumpkin was installed and everything I needed was working reasonably well, although there are a few bugs to note:

1. The 3G dongle that I bought from Pumpkin doesn't work very well. It connects to 3G but then after a few minutes of driving disconnects. Googling around, I discovered that the radio is manufactured by HuiFei and there is a forum that discusses issues with it. This is a known problem. Lots of interesting stuff to read about it here. 3G connectivity is not a key requirement for me, I mostly use the radio tethered to the WiFi personal hotspot of my phone.
2. The software can be a bit "crashy" ... The core functions work fine (radio, DVD, reversing camera, etc.) but if you play around with some Android Apps you will find that they sometimes don't work as expected. Also, sometimes various apps crash for no reason. Again, this is a mild annoyance since these apps are not a key requirement but more for fun. 
3. Since applying the "Battery Consumption Fix" (mentioned in point 2.3 above) the Pumpkin powers down every time I remove the key. This means that each new car trip requires the Pumpkin to boot up from scratch (unlike a car radio which is always instant-on). This can be annoying if you are making frequent small trips. I have wired up a switch to undo the "Battery Consumption Fix" (essentially a switch that can reconnect that cut wire) and when I am doing short trips I just leave that connected. It means that the radio only goes to sleep, but doesn't switch off. Hopefully I won't forget to leave this switch off at the end of the day or I'll have another dead battery.
4. The radio doesn't quite fit in as flush as the factory radio does. The bottom bezel sticks out a bit despite my repeated attempts to "force it in" for the last mm or so. It's flush at the top and sides so I'll just live with it.

Now on to the reversing camera which was a bit more of an adventure than I bargained for. This is not Pumpkin's fault since I could have just used the free camera they supplied and not faced these problems.

3. Installation - Reversing Camera

I basically followed the instructions provided in this YouTube video. I made a small change to the installation by drilling a much smaller hole in the back of the light holder. This meant that I had to cut the cable (since the RCA jack wouldn't fit through the smaller hole) and then I reattached it after I fed the cable through. I ran the cable to the front of the car and plugged it into the Pumpkin and it worked straight away by just switching the ignition ON and putting the car in reverse. But I did have some problems.

3.1 Reversing Camera - Engine Running Fix 

The first problem I ran into is that the camera would work fine with the ignition switch in the ON position, but once I started the car it wouldn't work anymore. This reminded me of some old car stereo buzzing problems I used to have years ago which was fixed by a noise isolator. So I bought one of these and wired it in. This worked perfectly and now the camera worked exactly as intended. As a side note, this Response brand of noise isolator has lousy instructions. Their web instructions don't match with the paper instructions that they provided. Follow the wiring diagram above with the green wire going to the +12V of the car and the red wire going to the power input on the camera.

3.2 Reversing Camera - LED Light Polarity Fix

At this point the camera was working great, but the license plate light that it was integrated with did not light up! The LED light, unlike the incandescent light that it was replacing, cannot be put in any-which-way. There is a + and a - side and they need to be hooked up correctly. This picture shows the light working fine when providing +12V to the left contact. But it wouldn't work in the car which provided +12V on the right contact. I could prove this by crossing the wires like in this picture. I contacted the vendor on eBay and after showing them these pictures they went back into their inventory and found a camera module where the LED was wired the other way and sent it to me for free. This was good customer service, but I wonder if Audi wires their cars differently in Australia? Because Audi uses incandescent lights the polarity of this wiring doesn't matter, but it does with LEDs.

3.3 Reversing Camera - Light Bulb Warning / CANBUS Error Fix

Now that the LED was working with the replacement camera module the car would give a Light Bulb Failure Warning (a.k.a. CANBUS Error). Because the LED draws so much less power than the incandescent bulb, the engine computer thinks the bulb is burned out. This meant a very annoying beep every time the lights came on. The next goal was to fix the light bulb warning. After some Googling around, I found this product which basically puts a load on the line to fool the engine computer into thinking that the bulb is there. You can easily do this yourself by wiring a resistor in parallel with the LED, but this solution was nice in that it was plug-and-play with the correct connections at either end. I also replaced the bulb on the other side of the license plate with one of these so that the lighting would be even and to avoid drawing too much load with the resistor packs.

And here is how the final installation looks of the camera with fully working LED lights as well!

Overall I am happy with the result, but it was a bit more involved than I had hoped. It took several months of elapsed time to sort out all these problems so I hope this little blog post can fast-track a solution to these problems for others in the same situation.

Here is the final installation with the camera working and my daughter helping me to test it.