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DIY: Adaptive Cruise Control retrofit on a Volkswagen Tiguan

23rd March 2021, 15:07 by Chirag Moro

A few of these issues cannot be improved no matter what we do, but I did feel it was possible to improve our factor of safety by upgrading the stock Cruise Control system in our car, to Adaptive Cruise Control.

fluidicjoy recently shared this with other BHPians.

Cruise Control has been a feature on the rise this last decade and now there are quite a few number of cars in India which sit in the budget segment and offer this feature. For the uninitiated, Cruise Control is a feature that maintains a Set Vehicle Speed and lets us take our foot off the Accelerator. Once Cruise Control is engaged, we can use the Cruise Control Switches to increase or decrease the set speeds. This is quite useful for super long drives and good free roads where you can maintain healthy speeds. Cruise Control in most cars I’ve driven has a minimum threshold of about 40km/h (might be lower for some manufacturers). There’s an eternal debate as to how useful Cruise Control in India is, considering even our highways do not have disciplined, lane traffic, with someone or the other cutting in and making us brake. I have quite a few funny memories about Cruise Control, but for the sake of keeping this thread focussed, I’ll share just one. While driving to a friend’s wedding in our Jetta a few years back, midway, the ABS-ESP Light started flashing and instantly, the Brake Pedal travel increased quite a bit. It was evident that the ABS would not kick-in, but the Volkswagen Repair Manual said, the Hydraulic Brake System would be perfectly functional even when the ABS-ESP Module was non-functional. True to that, I drove to Ahmednagar and back and extensively used Cruise Control to both accelerate and slow down proactively, since the stock Brake Pedal travel was uncomfortable after the ABS-ESP Module was disabled. It turned out to be the ABS Module going bust, and was not a Wheel Speed Sensor issue, and I'm still on my stock Wheel Speed Sensors (touch-wood!) So coming back to the point, Cruise Control can be quite useful if its there, but it is not without its share of problems.

Problems With Cruise Control

Unpredictable nature of Indian traffic and road conditions.
Lack of speed, lane discipline.

A few of these issues cannot be improved no matter what we do, but I did feel it was possible to improve our factor of safety by upgrading the stock Cruise Control system in our car, to Adaptive Cruise Control, and that is precisely what this thread is about, my experiences as I installed a Radar in the Tiguan and ended up with an upgrade in the degree of Autonomous driving. The first time I experienced a plethora of autonomous safety features was in a Volvo V40 and I was thoroughly impressed by how many safety features they had loaded in this car. Presently, the diesel Tiguan only has 8 Parking Sensors, while the AllSpace and T-Roc have a Radar and a Lane Keeping Camera and this image is a fair illustration of the different Driver Assistance technologies in play in our modern cars. I have had Adaptive Cruise Control (ACC) for close to a week now, and while the implementation has been flawless, it does have a few rough edges which can only be smoothened with the integration of Artificial Intelligence in these electronic Control Modules, and that might still be a few years away.

How It All Unfolded

Ever since we got the Tiguan a few years back, my dad was fascinated by quite a few tiny safety features it had, like Manoeuvre Braking for instance, which had prevented collision with small objects, by means of the Parking Sensors on the vehicle. He was wondering if the Tiguan would stop if someone suddenly came in the way, and that question of his, led to my research on Front Assist, which is what he would have liked to have, as we both had experienced it in a Volvo before. I conducted a thorough study of the equipment on offer in our vehicle, and sadly, the Radar was something which Volkswagen had not offered on the Diesel Tiguan. A pleasant surprise to me a few months later was that the T-Roc and Tiguan AllSpace were offered with not just a Radar, but also with a Front Lane Keeping Assist Camera in the Windshield, but what is weird is only a few of these features have been enabled by Volkswagen, while the rest, are practically a No-Show! In fact, I had mistakenly told a few friends that the AllSpace has ACC, since I had seen a few Radar features on the AllSpace, but little did I know, that they were not enabled from the factory. The test drive T-Roc was only capable of maintaining its line using the cameras. I really wanted to retrofit Adaptive Cruise Control in our car and started gathering all the minor building blocks to build this feature in our car. It took me about three months to source the Radar, Harness and a Radar compatible Volkswagen Logo and I almost thought I had it all, but I was so wrong, and read ahead to see the missing piece of the puzzle.

I had been procrastinating and delaying this installation from the last many months even though most of the required components had already reached me by mid January. I was perhaps a tiny bit afraid, of retrofitting something from scratch, that too on a near brand new car with just 9000kms under its belt, and 4 more years of warranty to go, but I decided to have a leap of faith in my research, and more extensively on my go-to guy for help @N2Autotech. I was so paranoid about breaking the trims in the car, that I even spent nights at a stretch to study Body Repair manuals for taking out the Interior and Exterior trims, as cleanly as possible, but the whole task was completed in under 8 hours, and it was a lot of fun, with the highlight being my Brake-Less drive home that night!

Overview Of The Steps

Installing a Tiguan specific Long Range Radar
Replacing the plastic Volkswagen Logo
Removing Interior Trims
Routing and wiring the Radar as per Volkswagen's original CAN route
Installing Cruise Control compliant buttons
Radar Calibration
Component Protection Removal
Coding and Adaptation
Test Run

So the first and most crucial step on the Diesel Tiguan was the physical installation of the Adaptive Cruise Control Radar. The Radar location on a Diesel Tiguan is behind the Front Volkswagen Emblem. I tried getting in touch with owners of an AllSpace and they sent me pictures of their ACC Logo and I was almost under the impression that my Tiguan comes with the same logo. Turns out, it's different! The Adaptive Cruise Control radar requires a Ceramic Logo to allow signal transmission and detect the vehicles and obstacles in the front. And it's not just made of ceramic, but its also flat, like Captain America's shield. It's ridiculously awesome and I even shared a story on my Instagram account asking folks whether it was 2D or 3D and this Volkswagen Logo managed to deceive about 72% of the folks who felt it was 3D.

Before I installed the new radar, I had to remove quite a lot from the Engine Bay, especially the intake components and they were considerably dusty and dirty. Finding an optimal route was quite the challenge considering how well shielded the engine firewall was. Then, I proceeded to unscrew and unclip the grill which was fairly dusty and dirty and so I thought it'd be a good idea to have the grill cleaned with pressure water. Here is what the Tiguan looks like without its grill and it sure feels like a moustache clipped off.

Next, I proceeded to install the Adaptive Cruise Control Radar in the designated housing in the grill. The Radar has to be handled very carefully and every horizontal movement has to be restrained otherwise the Radar loses its calibration. Now the funny part about calibration is that as of today, no Volkswagen dealership has a machine or VAS tool to calibrate their latest generation of Driver Assistance Systems, and we'll speak about this towards the end.

Here is a quick picture of both the logos side to side, and minus 5 marks for me for an unclean old logo, otherwise this would have been a very interesting photo to poll on. Next, it was time to lay the wires from the radar in the engine bay and route them to the vehicle. I have to say, that the interior quality of the padding and packing materials on this MQB CKD was top notch, with multiple layers of insulation for comfort in and around the firewall. When we got this car, I was pleasantly surprised to see that Volkswagen gave me a View Button on the right side of the wheel (for future use with a Virtual Cockpit) and something that looked like a Driver Assistance button on the left and I felt this would enable me to use Adaptive Cruise right out of the box. Sadly, I was wrong and I needed a new set of buttons to support Adaptive Cruise, as trivial and counterintuitive as that sounds, and this was the last piece of the puzzle.

The task at hand was to replace the stock buttons and this needed a removal of the Airbag and the surrounding trims to unscrew the old set of buttons.

I did this with quite a lot of patience and was fortunately successful, but if you attempt to yank the trims off, you will most certainly fail, or break something. So this is quite a critical task too in my opinion and needs a light hand and good trusted set of pry tools, and lots and lots of patience. This is what the naked steering wheel body looks like, and its awfully similar to the Polo and Vento, which obviously retail at a way lower price point. I'm sure Tiguan and T-Roc users paid quite a premium and would have loved something to distinguish their cars from lower steeds and an R-Line MQB Steering wheel would have been fabulous in these cars. For those who do not wish to merely replace the old buttons, getting a new compatible wheel is still a feasible yet 12x more expensive option.

The new buttons and their wiring needs to be routed along the guide-points in the wheel so that nothing comes off loose and there's no risk of any cables getting strained due to driving conditions.

Wiring

I followed Volkswagen's Wiring diagram to the T and took power from the fusebox from the rear, in the most appropriate way, and protected my installation with a fuse. I even identified a few convenient Earth points. As per Volkswagen, all of the Driver Assistance hardware (PDC, Lane Assist Camera, Side Assist, Adaptive Cruise Control) run on a single fuse. I really had a nice time working with the MQB harnesses. They were a stark contrast to the PQ platform connectors and one can definitely appreciate how sophisticated the MQB platform is from these little things. Accessing the fusebox needs removal of quite a lot of connectors including the Glovebox, Footwell lights and we also need to take out the brain of the infotainment system to take the glovebox off. Definitely not a great design for taking out and maintaining electrical wiring. In the future, I should be able to upgrade to Blind Spot Monitoring and Lane Keeping by using this same line of power, but I do not know when those upgrades might take shape.

Coding and Testing

Quite a few installations on the MQB Platform require what Volkswagen calls an FeC (Feature Enabling Code) or Swap Codes and so enabling features is no longer just a simple affair like ticking an installation in the gateway and enabling features from documented lines of code. That aspect is also very much alive, but Volkswagen India itself, is unaware of the presence of FeCs and even if they were, they do not wish to add to their headaches by adding more features to customer cars. I contacted @N2AutoTech (Nikhil) who completed the Online Coding and Activation formalities for me with a fee. I had also tried to reach Volkswagen and created a technical query asking about available FeC codes, but I received no response for weeks.

End Result

Once everything was done and the Coding and Component Activations were complete, Adaptive Cruise Control settings show up on both the Central 5F Infotainment System and the Instrument Cluster. I'm sure the settings would look even more beautiful on a Tiguan AllSpace and T-Roc with their Virtual Cockpits. My vehicle now has Adaptive Cruise Control upto 210km/h (something I do not plan on testing anytime soon) and also has Front Assist.

How it Works

Using Adaptive Cruise is fairly simple. Hit the I/O Main Switch and then press the vehicle and Distance Icon in the centre and the car starts locating a vehicle directly in line with the Radar Unit. Hitting the + and - keys helps to manipulate the Fixed Distance between the front of the object. Once the distance has been set, you can set a Max Speed.

Adaptive Cruise works to get the Maximum Possible speed upto the Set Speed within the Set Distance with the front object. So it banks on two parameters instead of just Speed in Cruise Control. And this dynamic nature of ACC makes it a more usable and enjoyable feature to have in our Indian driving conditions. If someone slides ahead into our lane, our vehicle slows down and starts tracking that vehicle instead. If there is a sudden vehicle slowing down, then the car can now autonomously brake and come to a complete standstill and all of this is theoretically possible upto 210 km/h which is insane! I've tried Adaptive Cruise Control for over 400 kms now which includes about 350 kms of highway driving and 50 kms of city driving, and its crazy how good it is at Autonomously Braking and Maintaining safe distances with vehicles ahead.

It takes a while to sink in, and I feel it takes even longer to trust that the Tiguan can now do Mumbai - Pune with your legs crossed on your seat. The car is so brilliant at accelerating and decelerating. The acceleration is delightfully quick and the braking is definitely a lot more calculated and gentle. For the sake of testing, I tried this on safe roads in the city and it was flawlessly maintaining distance from a targeted vehicle. The only downside I noticed was that the car cannot identify speed-breakers unless the vehicle in front is crawling really slowly on it as 30km/h which is the minimal set speed, is too high for most city speed breakers, unless you like bouncing around in your car. So I did find it usable in the city in traffic conditions, but its rightfully tuned for an extreme amount of safety, which is not feasible considering how we truly adapt to our real life driving scenarios of bumper to bumper traffic etc. A higher iteration of ACC may support Traffic Jam Assist but it mostly needs a Camera in the Windshield, so I'm waiting to see how well that turns out when AllSpace users get all of these features enabled.

Front Assist

Front Assist gives me a Visual Warning if I'm speeding a lot and the vehicle in front of me is a lot slower and shows up as an Exclamation Mark as a pre-warning. If I continue with that speed, the Vehicle first gives an Audible Warning with a Brake Symbol and if I try ramming into the vehicle ahead, the Tiguan now brakes on its own! It also works if a vehicle suddenly chips into my lane, provided it is doing so from the front and not from the side, as in that scenario, the radar would have missed it. Front Assist has characteristics which can be modified from the Infotainment Screen in Driver Assistance. My father drove to Lonavla yesterday and told me a Wagon-R chipped into the lane and created a sudden braking situation, which our car handled on its own, and so I'm happy that Front Assist seems to be doing its thing to improve the safety of our Tiguan. To be fair, I have been trying to test Front Assist myself and got it to safely brake and take over 7/10 situations. The 3/10 times, I had a feeling the car would not brake and I stepped onto the brakes myself. So I have to say, we need to still be alert despite having such advanced systems at work in our cars.

The Little Things

Flavours Of ACC
There are quite a lot of variants in ACC depending on what your vehicle has pre-installed and vehicles with a Lane Assist Camera can also potentially enable Traffic Jam Assist (ACC for Traffic Jams), ACC Stop and Go, and Predictive ACC (pACC) which also works in conjunction with the Navigation Map Data and Lane Keeping Assist to steer along a path, all on its own. Since the Diesel Tiguan did not ship with Navigation, nor do we have a Windshield Camera, I cannot try and confirm those for now, but I can safely say their India Specific Utility must be taken with a pinch of salt as Volkswagen India are still struggling with enabling Navigation on their AllSpaces. However, it is definitely certain that the future is bright for the MQB platform when it comes to enjoying the latest and greatest features.
Sensor Calibration
Whenever a Volkswagen meets with a frontal crash, or even undergoes a windshield replacement or even a rear axle alignment, the repair manual suggests a recalibration of the Adaptive Radar and most vehicular cameras, and the company most certainly needs to do it while rolling out from the factory, but presently, there is no provision to do it independently after. The camera calibration needs a mat, which is available at a few dealers or retrofit experts in India, but the Adaptive Cruise Radar calibration is a different ball game altogether, and needs a Laser Setup for calibration. I have a feeling its only a matter of months before Volkswagen makes these tools available to their large dealers.
Legal Implications
To be fair, I'm still reading about the Legal Implications and licensing of using a Radar on this car. As per a few experts, Volvo India had purchased a License for using Autonomous Safety features on the road, but there's a good chance Volkswagen is still on the fence about this affair. I still wonder why they took the effort to install a Radar in the Tiguan and T-Roc but CBU is the only bell that rings in my head when I think of that. I hope I find some clarity about this soon, and I hope I do not get pulled over in the Army Cantonment areas.
Warranty Implications
Technically, this would just be a Feature Enabling exercise on the AllSpace and T-Roc and should not hamper the vehicle warranty. On Diesel Tiguan, this is no doubt a Retrofit activity, but since I've not spliced any wires, I should be just fine when it comes to warranty. There are no fault codes on ODIS, the Official Volkswagen Diagnostic tool and there are no visible changes to the vehicle either. The steering looks the same, the front logo is the same, and you can only tell something is different when you go and touch it, which no Volkswagen executive would care to do, and the logo is so deceptive that nobody would really find out whether something has changed. If at all I've done anything, then I've only made this vehicle a safer car for us and others around me, and my friends have a hunch, that this might well be the first Tiguan in Maharashtra to have Adaptive Cruise Control.

What's Next

I'm still a fan of holding my steering wheel and I don't think I'd be upgrading to Lane Keeping Assist anytime soon. However, I've been a huge fan of Blind Spot Monitoring systems and the Tiguan is compatible with two such iterations. One of them is an indicator in the Mirror Glass itself, while the other is a small cutout in the Mirror Cap. If I had to pick an approach, I'd go with the later, since Mirrors are prone to staining and damages, while a Mirror cap might just last longer. This task would require two new Short Range Sensors in the Rear Bumper, and should definitely be a fun, rewarding and another big plus to the safety of what is already a comfortable safe SUV!