[swissknife]

I tried a few experiments on my GT TSI, though the Jetta and this may have different systems for hill hold.

1. Went up a slope. Applied the brakes till the car stopped. No additional pressure applied to the brakes. Took my foot off the brakes. The car did not move back. In about 2 to 3 seconds it started to inch forward.

2. Repeated the same as above, except that after stopping shifted to neutral and back to drive. The results were the same as in the first case.

3. Repeated the first test, and moved to Park and then back to Drive. The result was the same.

In effect, whatever the scenario, the car did not roll down the slope.

[tilt]

Originally Posted by GoBlue

Sharing observations based on a Polo GT TSI driven for 48k+ kilometers.



If the brake is applied 100%, the car does not roll back after releasing the brake (whilst the accelerator pedal is not applied).

However, in my observation if the brake pressure is not applied 100%, the car does roll back slightly after releasing the brake pedal.

Originally Posted by swissknife

I tried a few experiments on my GT TSI, though the Jetta and this may have different systems for hill hold.

1. Went up a slope. Applied the brakes till the car stopped. No additional pressure applied to the brakes. Took my foot off the brakes. The car did not move back. In about 2 to 3 seconds it started to inch forward.

2. Repeated the same as above, except that after stopping shifted to neutral and back to drive. The results were the same as in the first case.

3. Repeated the first test, and moved to Park and then back to Drive. The result was the same.

In effect, whatever the scenario, the car did not roll down the slope.

GoBlue & Swissknife, thank you for testing.

The VW senior tech (the Flying Doctor) claims that tests on the GT TSi and Ventos and Ameos are not representative and would not prove or disprove my point since they all are dry-clutch 7-speed DSGs and the Jetta is a wet-clutch 6-speed DSG.

I asked them how this is valid since hill-hold is not a function of the gearbox, but rather a function of the ABS subsystem; but they insisted on sticking with their opinion and that I was mistaken.

Cheers

[latentpotential]

Originally Posted by tilt

2015 Jetta TDI DSG Highline

This car has hill-hold assist which I believe is supposed to hold the car on an upward incline for about 3 seconds.

...

Any ideas on what else I could do to try and get them to do some trouble-shooting without fault codes?

The car is completely stock, no mods of any kind anywhere other than using a spare fuse to connect a dash cam.

Thank you and cheers

Hello, a fellow Jetta owner here. You can sort this out yourself, you need a VCDS cable, from within the last 3-4 years and 17.x version of the software.
I am sharing one video link

here

, but do also google for "vcds hill hold assist options" and you will see the relevant settings. Since these are software options, perhaps this is also why it is not being treated as an error, as it does not lead to creation of a fault code. Hope this helps.

[tilt]

Originally Posted by latentpotential

Hello, a fellow Jetta owner here. You can sort this out yourself, you need a VCDS cable, from within the last 3-4 years and 17.x version of the software.
I am sharing one video link here, but do also google for "vcds hill hold assist options" and you will see the relevant settings. Since these are software options, perhaps this is also why it is not being treated as an error, as it does not lead to creation of a fault code. Hope this helps.

Thank you - I am already aware that VCDS has these settings. However, this does not address the issue of why hill-hold worked fine until about a year ago (around 45000 kms) and then started to behave erratically for the last 45000 kms.

Also, by changing the settings in VCDS, it is the symptom that is being addressed and not the cause. I'd rather address the cause and let the symptom take care of itself.

I do appreciate your chiming in though - I am grateful for any help.

Cheers

[latentpotential]

Originally Posted by tilt

Thank you - I am already aware that VCDS has these settings. However, this does not address the issue of why hill-hold worked fine until about a year ago (around 45000 kms) and then started to behave erratically for the last 45000 kms.

Also, by changing the settings in VCDS, it is the symptom that is being addressed and not the cause. I'd rather address the cause and let the symptom take care of itself.

I do appreciate your chiming in though - I am grateful for any help.

Cheers

Would you mind checking with a new cable nevertheless? You may find the option disabled in your case. Do share a screenshot if comfortable.

[tilt]

Originally Posted by latentpotential

Would you mind checking with a new cable nevertheless? You may find the option disabled in your case. Do share a screenshot if comfortable.

I do not have immediate access to VCDS; but when I do I shall check.

Question - if like you said the option were disabled (or somehow made "inactive"), would I not be having the roll-back issue every time I stop on an incline rather than just randomly?

Cheers

[latentpotential]

Originally Posted by tilt

I do not have immediate access to VCDS; but when I do I shall check.

Question - if like you said the option were disabled (or somehow made "inactive"), would I not be having the roll-back issue every time I stop on an incline rather than just randomly?

Cheers

I would not want to conjecture, but your feature may be disabled, and you may be feeling the effect of the first gear roll at idle, which tries to keep the car moving forward.

[tilt]

Originally Posted by GoBlue

*SNIP*

If the brake is applied 100%, the car does not roll back after releasing the brake (whilst the accelerator pedal is not applied).

However, in my observation if the brake pressure is not applied 100%, the car does roll back slightly after releasing the brake pedal.

Originally Posted by audioholic

*SNIP* In case of Hill Hold, you are required to press the brake pedal hard and that pressure is held by the ABS/ESP module for a while before it is released. Hence, you should ideally be pushing the brake pedal hard for the car to hold it after you release the pedal. *SNIP*

OK, update time; and my apologies for leaving this hanging for so long - but I had to test it a few times; and thank you all for your helpful suggestions:

It turns out that it was a user error after all, there's no problem in the car itself.

Like GoBlue and Audioholic said, it works perfectly and consistently when I press the pedal hard and then let go. I discovered that I brake as gently as I can, and that's when I can see the issue. Obviously, when I did the test with the VW folks in the car, I was pressing the pedal hard and therefore could never replicate the issue!

I feel so "duh" for having wasted all your time.

Cheers

[voldemort]

Originally Posted by tilt

It turns out that it was a user error after all, there's no problem in the car itself.

Like GoBlue and Audioholic said, it works perfectly and consistently when I press the pedal hard and then let go. I discovered that I brake as gently as I can, and that's when I can see the issue. Obviously, when I did the test with the VW folks in the car, I was pressing the pedal hard and therefore could never replicate the issue!

While I'm glad that your issue has been apparently solved, I have a feeling something's not right.

For our Mercedes E-Class, I never have to press the brake hard to get the hill hold to activate. Touchwood.

Even if I make the car stop on an incline with a light press of the brake, releasing the brake would hold the car for about 3 seconds (hill hold) after which the hill hold automatically gets deactivated and the car starts creeping forward.

The behaviour mentioned is exactly the same as what swissknife mentioned.

Originally Posted by swissknife

I tried a few experiments on my GT TSI, though the Jetta and this may have different systems for hill hold.

1. Went up a slope. Applied the brakes till the car stopped. No additional pressure applied to the brakes. Took my foot off the brakes. The car did not move back. In about 2 to 3 seconds it started to inch forward.

2. Repeated the same as above, except that after stopping shifted to neutral and back to drive. The results were the same as in the first case.

3. Repeated the first test, and moved to Park and then back to Drive. The result was the same.

In effect, whatever the scenario, the car did not roll down the slope.

In other words, it's impossible to get the car to roll back a slope within the aforementioned 3 seconds.

In our Mercedes, hard braking when the car is already stationary (and the gear is in D or N) activates the HOLD function ― the thing you use to keep the brakes applied when waiting at a traffic signal for example (so you can take your foot off all pedals). And this HOLD stays activated as long as you don't press the brake or the accelerator again (there's no 3 second limit).

Why don't you (in a safe place) try hard braking on a slope, and then see if your car rolls back after 3 seconds? If it doesn't, then there's a possibility that what's holding the car isn't the hill hold.

[audioholic]

Originally Posted by voldemort

For our Mercedes E-Class, I never have to press the brake hard to get the hill hold to activate. Touchwood.

Why don't you (in a safe place) try hard braking on a slope, and then see if your car rolls back after 3 seconds? If it doesn't, then there's a possibility that what's holding the car isn't the hill hold.

Thats because your E class comes with a different ESP unit which is configured to work differently. The HOLD function uses the rear brakes like a parking brake which can stay as long as needed. This is similar to Auto Hold in the Passat. What Tilt has in his car is an older ESP unit which can only hold applied pressure for hill hold. This pressure is released in three seconds and the unit won't add pressure in case it is insufficient to hold the car standstill.

[WIMR]

Originally Posted by tilt

OK, update time; and my apologies for leaving this hanging for so long - but I had to test it a few times; and thank you all for your helpful suggestions:

It turns out that it was a user error after all, there's no problem in the car itself.

Like GoBlue and Audioholic said, it works perfectly and consistently when I press the pedal hard and then let go. I discovered that I brake as gently as I can, and that's when I can see the issue. Obviously, when I did the test with the VW folks in the car, I was pressing the pedal hard and therefore could never replicate the issue!

I feel so "duh" for having wasted all your time.

Cheers

I used to own a 2015 VW Jetta Highline and I can assure you that the car would not roll back on applying normal brake pedal pressure on an incline that would be enough to keep the car from rolling back (if you were to imagine you are without hill assist). This brake pressure is then retained by hill assist until you switch from brake to accelerator. I guess assuming you had the hill assist you were a little light on the brakes previously

[ike]

Originally Posted by tilt

Like GoBlue and Audioholic said, it works perfectly and consistently when I press the pedal hard and then let go. I discovered that I brake as gently as I can, and that's when I can see the issue. Obviously, when I did the test with the VW folks in the car, I was pressing the pedal hard and therefore could never replicate the issue!

I feel so "duh" for having wasted all your time.

Cheers

It doesn't add up though. How come you never had the issue during initial 45k KMS if this was the case? Did you change your braking style recently?

[tilt]

Originally Posted by voldemort

While I'm glad that your issue has been apparently solved, I have a feeling something's not right.

For our Mercedes E-Class, I never have to press the brake hard to get the hill hold to activate. Touchwood.

Even if I make the car stop on an incline with a light press of the brake, releasing the brake would hold the car for about 3 seconds (hill hold) after which the hill hold automatically gets deactivated and the car starts creeping forward.

The behaviour mentioned is exactly the same as what swissknife mentioned.



In other words, it's impossible to get the car to roll back a slope within the aforementioned 3 seconds.

In our Mercedes, hard braking when the car is already stationary (and the gear is in D or N) activates the HOLD function ― the thing you use to keep the brakes applied when waiting at a traffic signal for example (so you can take your foot off all pedals). And this HOLD stays activated as long as you don't press the brake or the accelerator again (there's no 3 second limit).

Why don't you (in a safe place) try hard braking on a slope, and then see if your car rolls back after 3 seconds? If it doesn't, then there's a possibility that what's holding the car isn't the hill hold.

That's because what you have is not hill-hold assist but auto-hold. There's a difference.

Originally Posted by WIMR

*SNIP* I guess assuming you had the hill assist you were a little light on the brakes previously

Yes, that's my guess too.

Originally Posted by ike

It doesn't add up though. How come you never had the issue during initial 45k KMS if this was the case? Did you change your braking style recently?

I honestly do not know. It could be that I either did change my braking style (not very likely though), or my memory is getting a bit faulty about the first 45K kms (quite likely). Am really not sure. Sorry, I am unable to answer this to anyone's satisfaction including mine. All I know is, it does seem to work now and I am relieved about that.

Thank you all once again, and cheers

[voldemort]

Originally Posted by audioholic

Thats because your E class comes with a different ESP unit which is configured to work differently. The HOLD function uses the rear brakes like a parking brake which can stay as long as needed. This is similar to Auto Hold in the Passat. What Tilt has in his car is an older ESP unit which can only hold applied pressure for hill hold. This pressure is released in three seconds and the unit won't add pressure in case it is insufficient to hold the car standstill.

Thank you for clearning that up. I didn't know the specifics of how they work.

Originally Posted by tilt

That's because what you have is not hill-hold assist but auto-hold. There's a difference.

I beg to differ. The E-Class comes with both the hill-hold assist and what you call the auto-hold (they just call it "Hold" in the E). And those two work differently (as mentioned in my earlier post).

Anyway, we're digressing. This discussion isn't about the features of the E-Class.

[audioholic]

Originally Posted by voldemort

I beg to differ. The E-Class comes with both the hill-hold assist and what you call the auto-hold (they just call it "Hold" in the E). And those two work differently (as mentioned in my earlier post).

Anyway, we're digressing. This discussion isn't about the features of the E-Class.

All the braking related functions are handled by the ESP module. This includes ABS, EBD, ESP, Hill Hold, Auto hold, Hill descent, Slip control, Brake drying and so on. The hardware is somewhat similar across ESP modules, just that its capability varies. But the basic functionality of any ESP system is it must be able to brake individual wheel on its own. What will differ is how much of braking force it can generate and so.

Since each manufacturer might not use the same ESP module, the features they offer as well as their behavior in the car will differ. Hence, we cannot directly compare this behavior between a Mercedes and a VW, or sometimes even a VW Polo and a Passat. Even if the hardware is the same, the way the functions are configured will be different. The newer German cars come with ESP modules which have a greater braking capability, since they are offered with Emergency braking and adaptive cruise control systems. Both of them use the ESP to perform autonomous braking duties either while slowing down during cruise or when they have to apply full braking force. The earlier systems only had to partially brake to stabilize the car but could never brake to the maximum possible extent. Cars like the E class have really powerful ESP units. If they give 100% braking force, you will experience insane braking which a driver would have very rarely used. When there is a system with so much of capability, the additional features like Hill Hold, etc work more flawlessly and more easily.