Nissan R32 GTR - Powertune Digital Dash Install Guide

[Dyzzii]

Hi all

I have just completed a PowerTune standalone digital dash install into my R32 GTR, and found there wasn't much guidance online around some of the nuances involved into doing this into the R32 GTR. I apologize in advance for not taking many photos of the project, but I will do the best I can to recollect and detail what is involved. 

Many hiccups came from how the R32 GTR gets its speedo signal to the different computers in the car, as me removing the OEM speedo causes that signal to be lost and messes with the HICAS and Power Steering systems in the car. Removing the OEM cluster also meant my ECU lost its speed reference, messing with any speed-related settings in the ECU itself. I.E launch control. 

It was super scary going into this with so many unknown factors, so my hope is that this helps at least one person do the same swap.

For reference, this install was done in a car with a Link G4+ ECU, however the premise will be the same for any ECU.

As I get time I can upload whatever photos and videos I have from the project in an attempt to make things clearer, and am happy to do my best to help others with the install. However, I am not super active on these forums, so flick me an instagram message and i’d be happy to lend a hand (@__DEZIAH).

First up, everything we used to install the Powertune dash and do all of the plugs:

• PowerTune Digital Dash + GPS Unit

• Mako Motorsports R32 Dash Mount

• Mako Motorsports LED Lights: Indicators, High Beam, 4WD, Check Engine Light, Door Open, Handbrake, ABS, Battery, Oil Pressure

• Wiring basics (Wiring tools, wire, loom tube, heat shrink, insulation tape etc)

• Link CAN Expansion Loom

• Digital Dash Fuel Level Dampener (My particular one was from Spiyda)

• OEM Nissan R33 GTR Gearbox Speed Sensor

• 1x 8 Way DTM Deutsch Connector

• 1x 12 Way DTM Deutsch Connector

• 1x 4 Way DTM Deutsch Connector

• 2x 2 Way DTM Deutsch Connector

Some of these parts may not be needed depending on how you want to do your install. I wanted to retain the functionality of the OEM harness, so that I could swap back to the OEM speedo if necessary and have it all work (all i'd have to do is reconnect the OEM speedo cable to the gearbox). I wanted it to be easily removable and tidy so we went with deutsch connectors to make the connection to the dash. I wanted the LED lights to be external to the dash for my warnings (and indicators, high beam etc), and most importantly I wanted fuel level to function and display on the dash.

Preparing for the installation

Start by removing anything and everything possible that could be in your way. Remove all of your interior trim pieces around the cluster, remove the OEM cluster, steering wheel etc etc. You want as much room to work as you can to make this process as easy as possible. I'd also suggest dropping your steering column to its lowest point to give you that extra little bit of room too.

Wiring The LED's

This was most likely the most time consuming part of the install. Because I wanted to retain functionality of the OEM harness, alot of splicing was required here in order to make that happen. I also wanted it to be tidy and easily removable, hence the use of multiple deutsch connectors. Below is what pins we spliced from the OEM harnesses, and what Deutsch connector we put them into. 

You don’t have to copy this exactly, and there may be a more optimal setup of where to pin everything, but this is what we did and it works.

Function	OEM Power	OEM Ground	DTM Power	DTM Ground
Indicators - Left	4	16	DTM 12 - Pin 1	DTM 8 - Pin 1
Indicators - Right	3	16	DTM 12 - Pin 2	DTM 8 - Pin 2
ABS	25	7	DTM 12 - Pin 3	DTM 8 - Pin 5
Battery	25	17	DTM 12 - Pin 3	DTM 12 - Pin 4
CAT Temp Sensor / CEL	25	29	DTM 12 - Pin 3	DTM 12 - Pin 5
Handbrake	25	12	DTM 12 - Pin 3	DTM 12 - Pin 6
High Beam	18	19	DTM 8 - Pin 3	DTM 12 - Pin 7
Door Open	25	30	DTM 12 - Pin 3	DTM 12 - Pin 8
4WD	31	32	DTM 8 - Pin 4	DTM 12 - Pin 9
Oil Pressure	25	34	DTM 12 - Pin 3	DTM 12 - Pin 10

These were wired into the Mako Motorsports LED’s which came with my dash, so it was as simple as matching them up and off we went. Be sure to test all of them as you go, as you don’t want to be chasing issues once you’ve completed all of your wiring. I have a bunch of videos showing all of this, but i’m unsure how to upload them here (or if I even can).

Wiring The Fuel Level Dampener + Fuel Level

The fuel level dampeners purpose is to stop your fuel level jumping all over the place. Without this, your fuel level signal will be jumping up and down and be an absolute nightmare to look at. 

The dampener requires a 5v power source to work, so we used one of my ECU’s spare 5v outputs to provide that power. My ECU also has a ‘sensor ground’ input, so we used that for the ground signal. Pin 6 on the factory harness is the fuel level signal, so that was spliced into to give the dampener the signal it was after. And it was then sent to the ECU using one of the spare sensor inputs.

I did not bother wiring up a low level warning LED, as I could set up my dash to display one if I wanted. But who really relies on one of those to tell you that you’re running low on fuel in a car like this.

The signal that comes out of my fuel dampener then runs to an Analogue input on my ECU, and the ground goes to the sensor ground input on my ECU. My ECU can now see my fuel level (after I calibrate it of course - of which I will outline further down).

Installing The New Speed Sensor

The R33 GTR speedo sensor slots straight in and works in the R32 GTR transfer case. Meaning this is a literal swap in and out job. Remove the one bolt holding your speedo cable in, unscrew the cable, then use a flathead to leverage the sensor out of the transfer case. You will lose some fluid doing this, so be prepared to re-fill it. Note: you can fill the transfer case back up through the gear shifter, as that is connected to the transfer case, NOT the gearbox in the R32 GTR.

Wiring The R33 GTR Speed Sensor

Due to the factory mechanical speedo drive in the R32’s, removing the OEM cluster creates a lot of issues. The car converts the mechanical signal that the cable gives the cluster, and converts it into an electronic one which is then sent out to multiple other computers in the car. This affects things like HICAS, Power Steering, and any ECU speed related controls. This means if you remove this connection, lots of this stuff breaks. 

Fortunately, it DOES NOT use this for the Atessa system, so your 4wd system WILL NOT be affected. There was so much conflicting information around this, with no clear answers. I have now done this myself, and can confirm 4wd works perfectly fine. I do not have an aftermarket 4wd controller. 

Our original hope was that we could wire the R33 GTR electronic speedo drive straight into the OEM speedo input wires on the loom (pin 13 for power, and pin 14 for ground), as in theory everything else would then work as intended. Power steering won’t get upset, and HICAS would still work normally. However when we attempted this, we made a mistake with the pinouts in our DTW connector, meaning it was not working. So we ended up wiring the electronic speedo drive directly to the ECU instead. Only then did we realize we had wired it incorrectly, so that it could have likely gone into the OEM location and all worked as intended. However we haven’t been able to confirm this, so it would be awesome if someone else giving this a try, can check and confirm. The rest of this guide assumes that this will not work.

All of my calibration stuff in my ECU software can be found further down into the writeup.

Power Steering Issue Explained

The R32 GTR has a ‘speed-assisted’ power steering system, which adjusts how much power steering assistance you get based on how fast you are going. This means you get assistance at lower speeds, but it reduces as your vehicle speed increases in an attempt to improve overall steering feel. Whilst an awesome system in concept, when you’re messing around with the speedo sensor, it breaks it. 

Once your oem speedo signal no longer works, around 30 seconds to a minute after you begin driving your power steering will become extremely heavy and basically turn off. IT goes into some form of failsafe mode as it gathers something has broken, and reverts to the lowest assist setting it has. You’ll have found this happen if you’ve ever snapped a speedo cable too.

The OEM system uses a voltage regulator based on speed to determine how much power is send to the power steering unit, ultimately adjusting therefore how much assistance you get. This leaves us with two possible fixes. 

Power Steering Issue - Fixes

First fix (the one I did), wiring in a voltage converter and setting it at a certain voltage to give the motor a constant voltage at all times. This means your power steering will have a constant feel at all times, so its a bit of a balancing act getting it right. Too much voltage going to the motor, steering feel will be extremely light at high speed. Too little, and steering will be too heavy at low speed. 

I purchased one from Jaycar (part number AA0236), and wired it in, bypassing the OEM system. Ryno did an awesome writeup of how to do this, so i’ll link that below. Personally, I set my voltage regulator to around 6 volts, as I liked the steering feel. This is all up to personal preference, and I dont mind it being a bit heavier at low speeds to have great feel when i’m actually driving. (Ryno’s writeup: https://www.sau.com.au/forums/topic/453968-r32-heavy-power-steering-how-to-disable-speed-variable-assist-steering-and-control-power-assistance-level/). 

I mounted mine above my brake pedal - that way the metal heat sink can dissipate heat effectively, its not in the way of anything, and I can easily adjust it if I ever feel the need. I’m sure you could also get fancier and wire this to some sort of dial and be able to control your power steering assist on the fly. But at this point, I just wanted it working.

The second fix, which is more complicated - is to use your ECU to control the speed sensitive power steering. I’m not super clued up on this, but you could essentially use your ECU to control the power steering motor. This link here detailed a bit of how to do this, but I never delved into it as it doesn’t bother me. https://www.gtr.co.uk/threads/reinstating-speed-sensitive-power-steering-without-hicas.507017/

HICAS 

Removing the speedo signal will also break your HICAS. However I absolutely hate HICAS, so it is removed from my car, meaning this is a non-issue for me. I’m sure there is also a way to fix this, but it is likely along the same lines as getting your ECU to control your hicas motor. Otherwise, be noted that HICAS will either outright not work, or act very strangely if you remove your OEM speed signal.

Wiring In The Dash

So at this point, you should have functional warning lights (indicator etc), power steering should be working again, and your ECU should be able to see your vehicle speed and fuel level. Now comes the easy part, wiring the dash itself.

This particular dash just needed a 5v power signal (it comes with a 12v - 5v converter), so we used that directly into one of the cars ignition sources. You need to ensure you use a good, strong signal for this, otherwise the dash will have issues with running under power and may not operate correctly. We went for an ignition source instead of accessory as I didn't want or need the dash running whilst I am just listening to music etc.

We then made a new ground for the dash and put it onto a bolt that goes through the chassis. 

This particular dash uses CAN to get the signal from the ECU and came with the required wiring. We plugged the supplied plug into CAN-2 on the ECU, and screwed the wires into the back of the dash. Not much more explanation really needed here.

Calibration

Now in theory, everything should be visible and working. All your signals and warning lights should work, your dash should power on, and your ECU should be able to see everything. Now, we just need to teach the ECU what everything does and means. Then, we need to tell the ECU to actually broadcast this data to the dash.

(The calibration data is all on my laptop which I do not currently have access to - I will upload further when I can).

My speed calibration settings:

My fuel level calibration settings:

My CAN broadcast settings:

My custom fuel level CAN broadcast settings:

Edited February 9, 2022 by Dyzzii
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Edited February 9, 2022 by Dyzzii
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[GTSBoy]

On 2/9/2022 at 8:20 AM, Dyzzii said:

Only then did we realize we had wired it incorrectly, so that it could have likely gone into the OEM location and all worked as intended. However we haven’t been able to confirm this, so it would be awesome if someone else giving this a try, can check and confirm. The rest of this guide assumes that this will not work.

The issue here is that the R32 GTR and R33 GTR speedos are both responsible for the actual speed signal that is sent around to all the CUs. The R32 creates it from the mechanical drive. The R33 creates it from the electric sender on the GB.

The difference between the 2 types of speed signal (the one for the CUs from the speedo head, and the one to the speedo head from the R33 sender) is that;

• The speed sender creates an AC +/- saw tooth signal, like any other reluctor style sensor will. This varies in frequency and voltage wtth shaft speed (obviously). The frequency of the zero volt crossings is essentially the speed information here.
• The speedo head outputs a 0-5v square wave PWM signal. The effective voltage (ie the width of the pulses) is the speed signal here.

You cannot feed the raw AC signal to any of the CUs that want the PWM signal.

I would like to think that you should be able to get an output out of that dash that will do it. If you cannot, you just need to parallel up a little Arduino based thing on the AC signal and get it to convert that input to the PWM signal that the CUs want. The details of what pulse width corresponds to what speed are in the R32 GTR manual. The details for the speed sender might well be the same as for the R33 GTST, but probably don't matter because you already have to have calibrated your dash from that input anyway, so you should already know what frequency you get at a given speed.

[Duncan]

By far the easiest and most accurate way to deal with the speedo issue is a GPS module for the ECU. If you have HICAS (but who does?!?!) you might need to output from the ECU to pin 53

[GTSBoy]

On 2/9/2022 at 1:49 PM, Duncan said:

you might need to output from the ECU to pin 53

Pretty sure that's not true Duncan. There is no speed signal output from the ECU - only input. All CUs that use speed signal get it off the same wire from the speedo head.

[Dyzzii]

On 2/9/2022 at 6:49 PM, Duncan said:

By far the easiest and most accurate way to deal with the speedo issue is a GPS module for the ECU. If you have HICAS (but who does?!?!) you might need to output from the ECU to pin 53

That was something I considered, but then if I went through a tunnel etc any speed related features would spaz out. I could be going through a tunnel and all of a sudden launch control would activate when the GPS loses its speed signal. Also i've gathered speedos can't be GPS based in order to pass a Warrant of Fitness check (6 monthly / annual vehicle checks required over here in NZ), so unfortunately it wasn't an option for me!

Super desperate to see if someone can test the R33 GTR speedo directly into the R32 speed inputs, as I have a sneaking suspicion it will work. Just not something I was able to verify as I had pinned something wrong and didn't realise until it was rewired directly to the ECU!

Edited February 9, 2022 by Dyzzii
Typo

[Dyzzii]

On 2/9/2022 at 5:48 PM, GTSBoy said:

The issue here is that the R32 GTR and R33 GTR speedos are both responsible for the actual speed signal that is sent around to all the CUs. The R32 creates it from the mechanical drive. The R33 creates it from the electric sender on the GB.

The difference between the 2 types of speed signal (the one for the CUs from the speedo head, and the one to the speedo head from the R33 sender) is that;

• The speed sender creates an AC +/- saw tooth signal, like any other reluctor style sensor will. This varies in frequency and voltage wtth shaft speed (obviously). The frequency of the zero volt crossings is essentially the speed information here.
• The speedo head outputs a 0-5v square wave PWM signal. The effective voltage (ie the width of the pulses) is the speed signal here.

You cannot feed the raw AC signal to any of the CUs that want the PWM signal.

I would like to think that you should be able to get an output out of that dash that will do it. If you cannot, you just need to parallel up a little Arduino based thing on the AC signal and get it to convert that input to the PWM signal that the CUs want. The details of what pulse width corresponds to what speed are in the R32 GTR manual. The details for the speed sender might well be the same as for the R33 GTST, but probably don't matter because you already have to have calibrated your dash from that input anyway, so you should already know what frequency you get at a given speed.

Ah that makes sense. I'm not super clued up on all of the inner-workings of this sort of thing, but did have a feeling they may not be compatible.

[GTSBoy]

On 2/9/2022 at 2:33 PM, Dyzzii said:

Ah that makes sense. I'm not super clued up on all of the inner-workings of this sort of thing, but did have a feeling they may not be compatible.

Yuh, you need to do one of the options in my post. If your dash can do it for you then you're gold. Otherwise you need to make an Arduino thing. You can get off the shelf boxes to do this. For example, Jaycar have a speedo converter that can take one type of signal and spit out another. But I think a DIY Arduino unit would be smarter. A small amount of non trivial electronics required to receive the AC signal into an Arduino. The PWM output is trivial. There should be a billion examples (not necessarily speedo related, but essentially the same problems) to work from on the net. Let me put it this way - I am no electronic circuit designer, and have no idea exactly what would be required to build the signal handling circuitry and set up the Arduino. But I am damn sure that if I needed to build one of these it would take me about an afternoon to do the research and could build it onto a proto board with one of my daughter's Arduinos that evening.

[NeoCef]

Hey man do you have the fuel gauge calibration values, going through this stuff now but not sure where to go with it

[TurboTapin]

Just wanted to add to two things to this post.

Concerning the speed input, originally the R32 cluster outputs 2450Pulses at 60KM's to the ECU, Hicas CU, etc. I recalibrated my Haltech GPS speed sensor to output the same and wired it to the same wire behind the cluster. I also adjusted my ecu accordingly. I have yet to fully test this as the car is not drivable for another month or two but I'm confident it should work. 

As for the battery light, there's no mention of also adding a resistor. A LED will not pull enough amps to excite your alternator. 

[TurboTapin]

On 9/9/2022 at 7:00 AM, NeoCef said:

Hey man do you have the fuel gauge calibration values, going through this stuff now but not sure where to go with it

Check voltage with an empty and full tank and you'll have your values. Cheers.