Carly Review – Car Scanning, Coding and Customisation* (For a price)

For those that haven’t heard of Carly, this is aiming to be a more user friendly version of dealership level diagnostic and programming tools that in theory will do everything from a proper all-module code scan, to coding features into your car that maybe the original owner didn’t opt for, or to just change settings that you can’t otherwise get access to. It’s a remarkably powerful tool, and one that seems like it’d be the best companion to keep in your car at all times. It has some pretty unique and impressive features, so let me start by showing you what it can do.

First, a quick look at their new “Universal Scanner”. This is a pretty typical OBD2 dongle, albeit remarkably slim and light. You’ve got the OBD2 port on one end, and the two status LEDs on the other. That’s pretty much it. You plug it in as you would any OBD2 dongle, then you’ll need your phone with the Carly app installed to connect to it. Once you connect – which takes a good couple of minutes every time by the way – you’ll be greeted with the dashboard where you’re presented with a range of options, including diagnostics, coding and live data. Now seeing as my car doesn’t have much wrong with it, I’ll use my friend’s F10 BMW 5 series as a great example of the diagnostic capabilities. It is as thorough as the dealership level tool, ISTA (which we do also have). The process for seeing all the errors is a bit more annoying – on ISTA it just lists everything that’s wrong, whereas on Carly they are split between each control unit. Still, you get all the same errors, albeit with often less useful error messages. For example the Central Gateway error codes we got said “Fscsm sends f60 invalid fingerprint” and just the word “Assert”. Still, to be clear these are error codes that you would not get on a regular OBD2 reader.

You can clear the codes – which is likely the most important function – or you can use the “Smart Mechanic” feature to learn more. For the one radio error I do have on my car, I can’t say that it is that useful. It gave me some ChatGPT level spiel about what CAN BUS is – including the data speed! It told me about the different CAN BUS systems, then gave me generic and fairly common sense things to check – but nothing remotely specific to this fault itself. In fact, if you keep scrolling it will show you other “related” CAN BUS errors and if you expand them you can see it’s the exact same text. In fact, a completely different CAN BUS error we found on the 5 series had the exact same text too.

 As some feedback for Carly here, this page is laid out really badly. If someone is looking for what to do about an error, giving them an essay about what the overall system is, isn’t useful. Honestly get rid of that – or replace it with a “learn more about CAN BUS” link or something. The bullet points should be at the top, and if you are going to say that “Carly’s expert mechanics have developed the following guide for your fault code”, then they should really be a bit more specific than what a simple google search for “CAN BUS communication failure” would provide. I mean this is a feature you are charging a hefty premium for, so I’d expect a premium feature. The “System” tab just lists that the VAG parts catalogue, ETKA, lists it as an electrics fault and some more ChatGPT type blurb about what “Electrics” means on cars. 

The “intelligence” tab is arguably the worst part, as it plays an animation, then it tells you a “potential” catastrophic error might be headed your way based on the error you currently have. This car is missing its EGR valve, so Carly thinks the turbo is going to explode soon – well there’s a “15% chance” anyway. While I can understand the intentions here, this feels like fear mongering to the uninformed. If they presented their sources, like “based on 10,000 users with your error code, 1,500 went on to have this error code”, it might seem more genuine and informed, but as it is now it doesn’t seem like something I would put any stock into. Is that based on 7 reports and one person had this further error? I can’t tell, so I can’t trust it. 

One of the main selling points Carly likes talking about is the ability to “code” your car. Basically changing hidden values in various control modules to enable hidden or locked features, or just customise various settings. A great example on my Audi S4 is the ability to turn off the feature where the hazard lights start flashing when you brake hard. I actually quite like that feature on the road, but when I took my car to Donington Park for a track day, it was pretty annoying and it would have been nice if I could have coded that out for the day. With Carly, I can. Now if you’ve seen Carly advertised before you’ll know this is very much a tool for BMWs. It does support some other brands and models, but on my 2013 S4 it has access to a grand total of three control modules, and only had one or two settings I can’t control through the car’s infotainment display, let alone through a specialist tool like VCDS. 

On the F10 5 series though it had access to ten modules and a plethora of settings you don’t otherwise have access to without the dealership level tool, INPA. That included some that my friend had wanted to code for a while, like turning off the annoying disclaimer that covers part of the backup camera display, turning off the “sport display” and showing the actual speed, not the “corrected” speed. It’s worth noting that a lot of these coding results seemed to be incorrect – like it said that “start engine without brake” was enabled, but it very much wasn’t. I think the coolest set of options though was for the seat heater – you can actually set the temperatures for each mode! If you’ve always found your seat heater too much on the highest mode, but too cold on mode two, you can tweak it to find exactly what you’d like – and each seat is independent so if your partner prefers a different set of temperatures, you can change that too. That’s pretty useful. 

Something else that’s useful is the “features” tab. Now again this is best on a BMW – it does have some functions on my Audi S4, like the rear brake service position, but on the 5 series it could reset engine and transmission adaptations, start a DPF regeneration, and even code batteries in too. One feature that should work on any car is the battery health monitoring feature. Basically you leave the dongle connected, and after 24 hours it gives you a report on your battery health and discharge per day. Now I’m not entirely sure how much I believe this as you are introducing a car-powered dongle that wakes itself up to read the battery voltage, which itself is using the battery’s power to do so… but 2.5% seems reasonable enough, if maybe a little high. 

Even for a BMW, Carly is nowhere near as powerful as ISTA and INPA – those have literally every function BMW has written for these cars, manuals specific to each problem, troubleshooting guides that are very much relevant to the problem, and every diagnostic test and function you could imagine. The big problem with tools like that are their complexity. You really need a like 4 week class to understand it all, whereas with Carly, while it isn’t anywhere near as powerful, it is beautifully simple to use. A little clunky and slow, but easy for sure. Of course, for anything other than a BMW, the proposition changes quite a lot. VCDS, a third party dealership level tool, offers infinitely more in terms of diagnostics, coding and functions. It is still a pretty dense UI that takes some time to get used to, but with the limited number of functions Carly offers by comparison, it’s pretty hard not to pick VCDS (or something like the OBD11 tool which is even more user friendly but just as powerful) over Carly. 

The final nail in the coffin for me is the pricing. On the surface, £60 for the dongle and all those features (or £79 for a BMW) seems like a great deal. Hell, paying the £9 or £27 more for “all brands” seems like a good deal. As I mentioned I’d skip the £36 “smart mechanic” feature personally, but for £87 all in that seems pretty decent. Until you scroll down a bit and zoom in on the unequivocally smallest text on the page. “The Carly licenses are an annual subscription”. So that £87, or £123 with “Smart Mechanic” is a yearly cost. For context, VCDS, the volkswagen audi group dealership level tool, is £185 for the 3 VIN unit. That’s two years of Carly subscriptions, for infinitely more features. For a BMW, if you are willing to acquire ISTA like 95% of enthusiasts do, all you’ll need is a £20 cable from Ebay and a spare laptop. Hell you could even buy a cheap used laptop from ebay for £100 and still be up on Carly. The fact that they are charging an annual subscription – for this much – is a complete deal breaker for me. While I am enough of a tech and car nerd to get on with ISTA and VCDS just fine, for that kind of cost I think a fair few people would be able to deal with the tough UI.

I think it’s really the trifecta of the annual subscription, for that much money, and the lack of capabilities compared to similarly priced tools – especially on anything other than a BMW. If it was cheaper, maybe £20 per year, it would be a lot easier to forgive, or if it was as capable as something like an Autel scanner that might justify the price, but as it stands I can’t imagine being willing to pay that sort of price every year, especially for my Audi. The “Smart Mechanic” feature is a bit of a joke really, it’s ChatGPT plus a google search. It’s not relevant or useful information, and it really isn’t worth £36 per year – at least in my opinion. 

Of course, those are my thoughts but I’d love to hear yours in the comments below. What do you think of Carly – is it a tool you’d pick up yourself or is the subscription a turn off for you too?