DIY: Retrofitting Traction Control Switch on a Mk6 VW Jetta

The retrofit is quite simple and a good weekend project.

BHPian prerak.kataria recently shared this with other enthusiasts.

Hey it’s Prerak, in this post I show the process of installing an ASR Off button in the MK6 Jetta, I installed this in my friend’s car (@das_mk6_jetta on Instagram).

This post won’t be an in-depth guide to how it’s installed, just a showcase of this retrofit and some highlights of the process, which is quite easy and a good weekend project.

What is the purpose of this extra button?

ASR stands for Anti Slip Regulation, it’s another way of referring to Traction Control, but since the MK6 Jettas cluster reads it as ‘ASR’ I will call it ASR in this post. But as far as I know, they serve the same purpose, which is to limit the loss of traction in all conditions.

This means that your vehicle cuts out power when one or more wheels spin faster than others, which can be annoying during enthusiastic driving and especially during launches.
To ask your ABS to ignore this, we need this ASR Off button.

Requirements

This Retrofit requires your vehicle to have ESP, I was not 100% sure if this Jetta had ESP, cornering lights indicated it did, which would mean it has a steering angle sensor, usually it is linked to ESP and it also warned of traction loss in the cluster.

Just to be safe, I jumped into 03-ABS brakes in VCDS and under advanced readings, I opened ABS/ESP and they toggled between On and Off to confirm it had ESP.

Furthermore, we need the ASR Off button kit.

This kit is very simple, one wire (the yellow one) to the ABS module, the rest of the wiring just takes ‘Power’ and ‘Illumination’ from the 12v socket nearby. The whole procedure is plug and play.

Procedure of installation:

Loosen the trim around the gear lever and change the blank with the ASR Off button

With the button placement correct, route the ABS signal wire out of the firewall and into the ABS pump connector.

This step will be easier in an automatic car and a little more difficult in a manual car

On right-hand drive manual transmission vehicles, the grommet is on the passenger side and the wire should run out of the passenger footwell. (Easier said than done, I’d think three times before doing it next time)

You can run the ABS signal wire through one of these nipples and plug it into slot #8 of the ABS pump connector.

That pretty much sums up the installation if you have a pre-2014 VW Jetta. Post Facelift cars were supposed to be coded via VCDS, but as this car was a pre-2013 Jetta, no encryption needed to be used.

Here’s a screenshot of the ECS tuning guide on this Retrofit to help code for Post-facelift Jettas

Also, there’s the PDF guide they have for this retrofit, which is exactly why I’m not going to go into more detail here.

Different kits have different ways of getting power, my kit was fully plugged in and playing and required none of this eavesdropping. My kit only needed a connector from a 12v socket from which it got power and lighting.

Footnote: Although this Jetta did not have a lit 12v socket, there was a lighting signal in the connector powering the 12v socket (perhaps a cost saving measure and a future retrofit?)

To work

With the installation complete. it was time to test its operation, with a rather massive hiccup along the way that was resolved, the ASR Off button could be tested, here it is in action.

Sorry for the low quality, this was taken right after the vehicle was repaired and I was finally able to test the button, with so much excitement I just pulled out my phone and took this quick clip.

Holding the ASR Off button deactivates the ASR, and pressing and holding the same button again activates it again. A sign will appear in the cluster and even the MID will warn and inform you about it.

What was the hiccup?

This is the reason I sat down to type this message. During the installation of this button, the signal wire to be routed to the ABS pump had to go through a grommet with a minimum of 20 (even more) wires.

In the back of my mind I was afraid to pierce one of them even after taking precautions it goes wrong. We took the time to install, but still managed to mess up the step I was worried about.

We must have screwed up on the signal wire leading away as we were greeted with these lights.

That red steering wheel means the ECU can’t reach the steering angle sensor, Tpms and traction lights are related to ESP errors, ESP would occur if it doesn’t receive signal from the steering angle sensor.

First thought:

“I removed the battery, these errors will surely come”

No Prerak, not if the steering is red, you would have been clear if it was yellow/orange, in that case you could just cycle the handlebars from lock to lock (which recalibrates the sensor) and you should have a clear dash.

second thought:

“I must have blown a small fuse while reassembling the battery”

Never in my life have I wished for a blown fuse, but in that moment I hoped with all my heart that it would be a blown fuse.

But all fuses are blown.

A whole day of checking reachable connectors also did nothing, took it to my local FNG

Their first thought:

“We need a new wheelhouse”

I was not convinced at all, I was sure it was a small leak in the wiring.

I persuaded them to check the rack connections and focus more on the wiring than the rack.

After a few days of digging (they couldn’t work on it all the time, we would just tinker in my presence) we found that the wire for CAN Low was torn somewhere in the harness. Under no load there is a potential difference of 5v between CAN high and low, under load it is 3v (correct me if I’m wrong, I’m not sure about loaded/no load conditions, but sure about the values)

But the steering rack connector would not read continuity for CAN Low nor did it show a potential difference.

So we took the armor apart further and found the cut, it was under the grommet, away from where I expected cuts or damage, I thought it would cause problems right at the cut of the firewall, anyway, the cut was repaired with a piece of OEM CAN Low wiring (didn’t want to put another color on it, would avoid confusion for future mechanics) Steering angle sensor reactivated via VCDS and also calibrated.

ESP, CAN and ECU were quite happy after this cut was fixed, it took the better part of a week to locate. I was relieved that those errors were fixed, but it took a huge toll on my confidence working on cars. It made me so grateful to own a vending machine with massive throughput that allows us to route everything through the firewall. This retrofit has made me afraid to work on manual cars if it goes through the firewall.

If any of you want to do this retrofit, be a million times more careful, I know I’ll be there next time.

But what have we learned:

I learned a lot about the technical details and operation of the ABS pump and steering rack, especially the steering angle sensor, I understood ESP a little better, these are notable features that we overlook when buying a vehicle, although newer vehicles come standard with such features, but not all manual vehicles do.

I’ve learned to diagnose better, even if no case is the same, but still, after a week of digging in the car, I knew where to look and what to check under certain circumstances.

I’ve learned the importance of patience, even if we took the time for this, maybe there was room for more patience, more care.

Unexpected things happen, this cut, under the armor, even after being patient and careful every step of the way, took things in a whole new direction with this retrofit.

Conclusion

But after all that my friend was happy with a functioning ASR Off button, they enjoyed their launches much better and liked the screeching tires without the car being limited by its safety feature.

Most of all, they were happy that their car had received a real retrofit, they had been helping and assisting me with my retrofits all along, even when they bought their car they said they were looking forward to all the technical retrofits we would do on this car.

There would definitely be a lot more coming to this car if it remains under their ownership and my closeness, they change cars often so I can’t promise anything. Anyway, I hope you enjoyed this showcase of the ASR Off button and my experience installing it.

Check out BHPian’s comments for more insights and information.

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