Project BRZ, Head Unit Install

Having arrived home with the new car the day before, I took no time at all to start ripping the car to bits.

The first thing to fix was going to be the head unit. I had previously purchased another of the cheap Android units from AliExpress, the same I had used in the Alto, in preparation to fit it in my next car, so once I bought the relevant wiring and fascia adaptors, I was ready to get stuck in.

I started by removing the surrounding trim, which came free by hand

Where I immediately came across my first problem. Being the stock head unit, it still had the stupid security screws fitted. As if anyone wants to steal a stock head unit that badly.

Nothing a garage full of tools can’t fix though. A small bolt extractor was the perfect solution

Upon removing the unit, I was greeted by the obligatory JDM nest of wiring behind the head unit

It took a lot of work to unpick all the wiring and dump what wasn’t needed

All the black wires with the square plugs are for various antennas around the car, which would require a lot more disassembly than I can be bothered with, so they were bundled up, taped up and zip tied out of the way. This left with me with the two main connectors, the FM antenna harness (with adaptor) and a 5 pin connector which has the reverse camera trigger on it.

As a side note, the wiring adaptor required is for a Toyota, showing the car’s shared roots. In NZ it’s an Aerpro APP0141

I also needed some little filler plates for either side, since the standard head unit is wider than a normal Din unit. These were Aerpro ATB2

Along with all the wiring for the head unit, there was also wiring for the ETC unit in the glove box, which all had to come out. This turned out to run all along the dash, to under the steering wheel

Where I also found this weird bundle of wires with heaps of unused bullet terminals

As it turns out, this is actually a genuine accessory. Part number H0077AL000 – Option Harness, which ties into the car harness and gives a bunch of “outs” to use for various things

It appears the DRLs tie into it, as does the ETC unit and reversing camera trigger. Very handy!

Anyway, back to the head unit. This is where it all started to turn a bit pear shaped.

The Android unit is very shallow, so the brackets need mounting holes quite far forward (an issue I had in the Alto), but putting the two side by side looked like I should be good

The filler plates needed some modifying to clear the mounting brackets. I had to cut a lot more out of these later on

A quick test fit in the surround. It’s VERY tight, I suspect the Android unit might be a fraction taller than the Din standard.

I cut the ISO plugs off the adaptor harness, and wired it to the head unit wiring, ready for a test boot

Excellent, everything seemed to be working. So now it should just be as easy and screwing it in and pushing the surround on over it, right? No.

This part of the job took the longest. In the end I had to file the mounting holes on each bracket into slots, so I could lower the head unit down as it mounted too high and clashed with the dash, and finally it took me a while to realise the filler pieces needed to be moved backwards a hole, and can’t mount flush with the unit otherwise they actually try to share space with the surround, which is no good. This took a horrible amount of test fitting, back and forth, to get it to fit right.

In the end though, it finally did

And the two reasons I wanted this unit, worked

The audio quality, like in the Alto, isn’t great, but the original head unit didn’t sound amazing either (clear, but lacking bass), so I’m not sure if that’s just normal for these. At the end of the day, I just want background music for commuting. Most of the time when driving this, I’ll want to be enjoying myself and concentrating. The main function is Waze and being able to use Torque Pro.

Speaking of Torque, one function that was missing from the Alto is present on the BRZ; engine oil temp. This isn’t the final layout, but good for testing.

This has to be added with a custom PID in Torque, based on instructions in this thread here and using these settings

OBD2 Mode and PID: 2101
Minimum Value: -40
Maximum Value: 215 (this is just the maximum that this location can support, which does not mean the sensor can read that high)
Scale factor: x1
Unit type: C
Equation: AC-40 (no space between A and C; “AC” is the location within the response)
OBD Header: 7E0 (Auto also works, but seems to take longer)

Seems to work well and responds as expected. I still really rate these little cheap head units. They’re far from perfect, and if you’re into good audio I wouldn’t bother, but for the functions they offer, it’s hard to beat.

One last little bit of work, while I was under the dash, was to fit my Pivot throttle controller. By some miracle, this car uses the Toyota harness, which I happened to have already since I last used this on the Yaris.

I disconnected the throttle pedal harness

and added the Pivot harness in line

I tapped into the option harness for switched power, connected the ground to a bolt, and job done.

The main reason to add this wasn’t to improve throttle response, but to actually dull it down. This one does both Sport and Eco modes, and as I found out, turning it to Eco2 was enough to dull the pedal response and make the car more drivable. This was just masking an issue I would find the solution to later on.