Cruise control unable to maintain speed

[Motorsport101]

Majority of our motorways are not flat, having slight bumps or inclines/declines. Our 2 month old ZS struggles on these, with a constant increase in power and immediately, decrease in power before repeating this process over and over. Feels your on a boat riding the waves. On the same roads, our E-Golf, previous Tesla model S or any of our ICE cars managed to cruise consistently regardless of the road surface. Anyone else experienced this or managed to resolve? I tried using different driving modes and Kers settings. None helped.

 

[Gadget Geek]

Not noticed it in mine.

 

[Bodgerx]

Majority of our motorways are not flat, having slight bumps or inclines/declines. Our 2 month old ZS struggles on these, with a constant increase in power and immediately, decrease in power before repeating this process over and over. Feels your on a boat riding the waves. On the same roads, our E-Golf, previous Tesla model S or any of our ICE cars managed to cruise consistently regardless of the road surface. Anyone else experienced this or managed to resolve? I tried using different driving modes and Kers settings. None helped.

On occasion I noticed a little bit of this behaviour on my recent trip to France. It only seems to be if there is a sudden incline/decline and doesn't last long. The affect does seem to be worse if the road surface induces bouncing from the ZS's unsettled ride at the same time - I think that must confuse the wheel speed sensors in some way.

 

[Alb]

How far is it falling short of the set speed?

 

[Motorsport101]

It bounces around 3-5 mph. Power meter fluctuates from zero power to over 50% and back to zero and back up again depending on the road surface. All other cars I've owned can judge or handle a change in surface or road pitch quickly with no jolting in the cabin. The M3 is fairly flat but a small crease in the road and we are rocking back and forward as the car tries to correct it's speed. It's very odd.

 

[Alb]

With KERS3, my car never strays more than 1mph from the set point. That could be exacerbated if the car were heavily laden but 3-5mph doesn't sound right.

 

[peterseddon]

With KERS3, my car never strays more than 1mph from the set point. That could be exacerbated if the car were heavily laden but 3-5mph doesn't sound right.

KERS isn't used in ACC, it uses the brakes to slow down. My car doesn't stray by more than 1 mph from the set speed.

 

[IanSS]

I am up and down the M74 on a regular basis and that is very lumpy. Never see any noticeable drop in speed using ACC when climbing. It does however reduce speed on some bends in the road when ACC is set so could that be a contributing factor to what you are seeing?

 

[Tim Green]

The ACC on my car is very stable. Taking up IanSS point, could the radar unit be incorrectly set so that it is recording the bumps and hills as an obstacle? Sounds like a fault to me.

 

[Exdro]

Majority of our motorways are not flat, having slight bumps or inclines/declines. Our 2 month old ZS struggles on these, with a constant increase in power and immediately, decrease in power before repeating this process over and over. Feels your on a boat riding the waves. On the same roads, our E-Golf, previous Tesla model S or any of our ICE cars managed to cruise consistently regardless of the road surface. Anyone else experienced this or managed to resolve? I tried using different driving modes and Kers settings. None helped.

Ours maintains a steady speed. If you are approaching another vehicle from behind, the ACC will reduce your speed to match. Always use it on N mode and Kees 3. Sounds as if you have a fault.

 

[steve1973]

Mine does this occasionally when fixed at 70mph it tends to read 69 or 71 fluctuating with the terrain.

 

[wizzer99]

Majority of our motorways are not flat, having slight bumps or inclines/declines. Our 2 month old ZS struggles on these, with a constant increase in power and immediately, decrease in power before repeating this process over and over. Feels your on a boat riding the waves. On the same roads, our E-Golf, previous Tesla model S or any of our ICE cars managed to cruise consistently regardless of the road surface. Anyone else experienced this or managed to resolve? I tried using different driving modes and Kers settings. None helped.

I have a 1 year old ZS LR. Never had that issue.

 

[profdraper]

Zero issues here with two ZS EVs over the years (gen1 and now gen2), in fact cruise control & auto distance keeping would have to be one of the best features of the car & so good also for general efficiency /battery range. I'd be inclined to have it serviced & checked.

 

[X4vl]

There are only two things that can affect speed. The distance to the preceding car and the road curves at high speeds.

 

[DBedford]

There are only two three things that can affect speed. The distance to the preceding car and the road curves at high speeds.

Or dips in the road!

 

[MikeN]

Mine does this occasionally when fixed at 70mph it tends to read 69 or 71 fluctuating with the terrain.

That seems to be within the normal parameters Steve.
Mine mostly runs 1 mph slower than the set target.

 

[Tread Softly Terran]

Like others I've only noticed a 1mph variation, unless a certain 'bouncing' creeps in. Even then it sorts itself out very quickly. (I've just arrived back from 210 mile journey Paignton to Gatwick heavily laiden & had no issues at all).
I agree might be a fault or a software update needed?

 

[capitan capete]

If what you mean is that it doesn't hold speed, my mg4 has that problem, on rural road and highway.

It is very uncomfortable to constantly accelerate and brake, but the greater the turn in a curve, the more speed it loses and the faster it accelerates when exiting a curve.

 

[peterseddon]

If what you mean is that it doesn't hold speed, my mg4 has that problem, on rural road and highway.

It is very uncomfortable to constantly accelerate and brake, but the greater the turn in a curve, the more speed it loses and the faster it accelerates when exiting a curve.

The software is programmed to slow you down when you turn a corner, the sharper the turn the more it will slow you.