Confused

Most Link ECUs are probably installed in the cabin, where the supplied USB cable is sufficient. It's generally only where you've got the ECU somewhere else, such as in the rear of an MR2, where you need a longer cable, and the standard electrical system is pretty "noisy" that you start to encounter issues.

The G4X Xtreme is a Wire-In ECU, all of its available functions are available through the two main connectors. The Expansion Loom is for the vehicle-specific Plug-In ECUs, where the vehicle header doesn't have all pins available, so up to two Expansion ports are offered to add additional inputs and outputs on top of the basic functionality required to run the engine. So - if you've actually got an Xtreme, you don't need any Expansion looms, and you do not want to be drilling anything anywhere!

MAP = Manifold Absolute Pressure, this is how far above absolute vacuum, it's always positive. You're probably confusing it with MGP (Manifold Gauge Pressure), which is relative to your current atmospheric pressure, negative for values below this (in vacuum) and positive for values above this (in boost)

From the Help: So, looks like you'll connect your Link CAN Lambda module's CAN H and CAN L to pins 28/29 The Help within the PC Link application is exceptionally good, the best Help I've seen in 20+ years in the software industry.

Which specific G4X do you have?

If it's anything like my Legnum VR-4, scan tools never give an accurate list of faults, but the "flashy dash" method that Adam has mentioned always does. You've also not answered the question as to whether anything else has been modified on the vehicle other than simply swapping out the stock engine ECU.

The two are incompatible, which is why you can't open the old in the new. There is no automated import of configuration from G4+ to G4X. You will do best by opening a copy of each application, and going through the configuration bit-by-bit, comparing old settings with the new settings (and Help documentation) to configure in the new method, as many things have changed substantially. It is really important to read the documentation for G4X, even if you think you know how it works in G4+, because things are different - one example is Triggering - this had me stumped for a few hours troubleshooting before I RTFM and saw that I was using the wrong settings, as I'd copied it blindly from the G4

OK, so looking again to try to point you at it, it looks like it doesn't mention it specifically, but piecing together various E-Throttle related things, the wiring tells you to use Aux9/10 outputs, and the setup side tells you to set Aux4 and Aux9 for E-Throttle Signal 1/2 outputs.

That is indeed correct, Aux 10 isn't visible in the ECU Settings. As noted in the Help, you use Aux4 and Aux9 in software, which get automagically translated to Aux9/10 for E-Throttle output.

CAN is fully digital signal between the devices, the "old school" way is that the wideband controller will convert the digital signal it knows about, and output a "0-5v" analogue signal, which the ECU then has read as an input, and convert back to a digital signal - but what the controller thinks it's outputting and what the ECU reads doesn't necessarily match (especially with the awful AEM 30-4110) - which means that the ECU doesn't have an accurate detail of the measured lambda. Sticking with CAN, this is a purely digital signal the whole way, so it's much more accurate. The Link CAN Lambda has two-way communication with the ECU too, and much better error reporting, which is why I recommend it - there's some things to not "cheap out" on, this is one, injectors is another, and as koracing says, fuel pressure sensor is really useful too.

If well tuned, a wideband isn't necessary, however having one allows a few extra safety features to be enabled, such as Closed Loop Lambda, limiters if it goes too rich or lean. The Link CAN Lambda module is one of the best in my opinion, so I'd invest in that over a different brand. You don't need any kind of display, but again, it's a nice to have, especially a CAN based one that can show you warnings etc when the ECU detects them. You could use an old phone/tablet with RealDash but it's not quite as "nice" as a dedicated gauge, there's the potential that the battery has gone flat between uses of the car, and you need to wait for it to power up etc before you have your display output. But, basically, yes, you can "just" plug it in and tune it with a laptop and require nothing else ongoing.

I believe there are two sizes of ECU boards and cases, so the board is designed to have section that can be removed by the end user, if necessary. I've not personally had experience with a Link board of this type, but traditionally on circuit boards designed in this way they will snap off, or can be carefully cut with sharp cutting pliers or with a knife.

Have you done a TPS calibration now that it's moving under its own power?

Have you also connected the Enable input (White) on the G4RET to the output you've selected for the E-Throttle Relay - Aux 5 (pin A-7)?

You have the outputs configured as Aux1/2 - do you have the external E-Throttle Module https://dealers.linkecu.com/G4RET connected to Aux1 & Aux2? If you're trying to use the in-built E-Throttle driver, you have to use Aux9/10 The ECU seems to be correctly commanding the E-Throttle Target, but I think you've got it wired up incorrectly.

The outputs have a weak "pull-up" to 12v (so this is what your meter will be seeing) and when turned on (they show as "Active" in the software) they will be switched to ground. So - your fan relay should have an ignition switched 12v feed to one side of the coil (if using a typical automotive relay, the one labelled 86), and the other side of the coil (pin labelled 85) goes to your Aux output. The same ignition switched power supply goes to pin labelled 30, and your fan's positive lead to pin labelled 87, with the other side of the fan to ground. I will say though, that there is already an Engine Fan function built into the ECU, which will be better to be used - it supports more features than your attempt using a GP Output, such as hysteresis (which will prevent the fan turning on and off as the ECT goes either side of your set-point), and this can be used to modify the idle settings when enabled, due to the extra power drain on the electrical system, which the GP Output function won't do.

I think something similar is applied in the 350Z base map, this is a Modelled Mode setup, where IAT Trim is usually disabled, but due to the heat soak, they use the IAT compensation too. But always useful to see different approaches to issues like this

What benefit do you think a written language learning algorithm has when applied to engine tuning? What could this give over the existing functionality such as Quick Tune, Mixture Map, Long Term Closed Loop Lambda Trims? What other features and enhancements do you want to not get? I'm not trying to be difficult, but I'm not immediately sure how this feature could be implemented in a useful way - hopefully you can make some suggestions!

I agree compelely with @koracing - sell that AEM gauge off to some other unsuspecting person who won't ever be hooking it up to an ECU, and get a Link CAN Lambda module ASAP. I honestly spent days fiddling around, tuning and retuning the same areas of the table over and over as it would be totally different day-to-day with no other changes. (I'm just doing road tuning with log files/mixture map mostly). Once I switched to the Link module, I wasn't changing the same cells over and over each time, each drive had fewer and fewer changes to incorporate, and it ran much much better. If you're paying for dyno time and expecting the ECU to work well, it's a waste of money not just buying the right bit of kit ASAP and trying to "make the most" of the rubbish you've currently got.

As far as I'm aware, The reason that the Plug-in ECUs are priced as competitively as they are compared to the Wire-In ECUs because they have those limited inputs and outputs, and you'll notice your Honda one is cheaper than some other Plug-In versions which use more of the inputs and outputs. Do I totally agree with this, knowing there might be unused potential I can't get to? Yes, but also no. Yes, because I want it, but No because I paid less than the cost of an Xtreme wire-in to get into the Link ecosystem on my car. It's a trade-off.

@Vaughan that looks great. Is there any chance of little Quality Of Life tweaks being applied to PC Link for the G4+ range - especially as the Force and Thunder are still active products in your range? (I appreciate the firmware is getting pretty full for ECU features, but there's no limitation on that for PC Link, though?)

It's also likely to change every time you drive the car, too... I spent days chasing my tail with it, until I ripped it out and replaced it with a Link CAN Lambda.

From what I remember, I think that the Engine Fan functionality won't turn on the fan if the engine hasn't yet started, so this is likely why modifying your values isn't working as you expect. You can however use the Test function to check your wiring. Edit: I've just re-read, and I think this is what you're doing... so it's probably a wiring issue... All outputs on the Link ECU switch ground, so you need to ensure that your fan relay is set up with an Ignition Switched feed to one side of the relay's coil, and the other side of the relay's coil is connected to the Aux output on the ECU.

You can use any brand of wideband controller, so long as it outputs an analogue signal, or via CANBUS and the protocol is known. However, the Link one is one of the best in my opinion. It talks bi-directionally to the ECU, doesn't heat the sensor until the car is running (prolonging sensor life), informs the ECU if it detects any failures, is a fully digital signal, so no conversion inaccuracies, very quick (I think I read here it transmits 100 updates per second, it certainly updates the values very quickly).

I noticed that my fuel pressure sensor wasn't correlating with the gauge on my FPR. As a man with one watch always knows what time it is, and a man with two watches is never sure, I had to verify with a 3rd source which I was confident was reading accurately. So, I tee'd my FPR gauge, fuel pressure sensor, and the ECU's built-in MAP sensor together, and with an adjustable pressure regulator from my compressor (which had yet another gauge), I found that the fuel pressure gauge was reading incorrectly, but the sensor matched the MAP and regulator's gauge. It kind of seems like the fuel pressure is tracking somewhat with the engine's MAP, but your differential fuel pressure should be pretty solid at 300kpa. Maybe you do only have a ~190-200kpa base fuel pressure without the manifold vacuum/boost reference?