Expert answer

Hi John,

Lots of people find that their car's stop-start system stops working for no obvious reason, though it's disappointing that the garage fobbed you off rather than come up with a fix. 

We've had so many queries that we've put together a guide called Why won't my car's stop-start system work?

Have a read through that and see if it helps shine a light on the situation. Faulty temperature sensors and batteries in poor condition are very common causes.

Expert answer

Hi Roy, 

That's not something we've come across, I'm afraid. There can be many simple reasons for a stop-start system to not work (see our popular feature on that subject here), but usually they are temporary. I guess if your battery was replaced, there may be some additional reprogramming required, but that wouldn't be standard on all cars.

If someone has told you that this is necessary, make sure you get a second opinion from another garage, preferably an official Suzuki service outlet. And if Suzuki told you that, then ask for a little explanation.

We'd be interested in the answer if you want to pop a comment in below this at a later stage.

Expert answer

Hi Anne,

There are loads of different reasons why a stop-start system won't work as you might expect it to. Most of the time it's down to the condition of the battery or the drain on it, though it could be due to the ambient temperature, too. Here are a couple of items on the site to read through before you consider having the car looked at:

Why won't my car's stop-start system work?

Why does my stop-start not always work?

Expert answer

Hi Juliana,

We don't know of any common issue with the Insight, so it's probably a protection mechanism for the battery. We get a lot of similar queries, which prompted us to write the Why won't my car's stop-start system work? feature - well worth a read.

Expert answer

Hi Janie,

On the parking sensor issue, it just seems to be a bit of a quirk with the Audi Q7 that to get the front sensors on when moving forwards, you have to press the parking sensor switch, although they do, as you point out, come on automatically when you select reverse. We’re not sure why this is, but it might be worth a visit to your dealer to see if there’s some finicky bit of software code that can be re-set to activate them automatically at low speeds.

As for the stop-start system, if could be a few things. Obviously, there may be a fault, in which case get the car booked into your dealer for a check-up. Or it could be that you’re doing a lot of low-mileage, short runs, which aren’t allowing the engine and other systems to get fully up to temperature. Stop-start isn’t a simple on/off system — it’s controlled by the engine management and that won’t let stop-start activate if it thinks that the engine hasn’t warmed up enough (stopping and starting a cold engine can be damaging) or if it has detected that you have a lot of high-energy drain systems (air conditioning, demisters etc) running. Try and analyse your driving the next time you go out and see if any of this fits. If not, head for your dealer. 

Expert answer

Hi Silvester,

We have got so many questions from readers about non-functioning stop-start systems (from all makes and models) that we put together this guide to help you get to the bottom of it:

Why won't my car's stop-start system work?

Expert answer

Hi Tracy,

I'm afraid without knowing exactly which car you have, this is impossible to diagnose. You should bring the car to a good mechanic or auto-electrician.

There are many reasons for a stop-start system to not always work. Read this question and answer on that subject for instance.

Expert answer

Hi Anna,

There are plenty of reasons why a stop-start system won't work in certain circumstances. It's different for every car, but it's well worth reading this other reader question for a general overview, even if it doesn't specifically apply to your car. 

If none of that helps, then pop along to your Peugeot dealer, as the car is still under warranty.

Expert answer

Hi Emma,

I think a hybrid could well suit you, and with your M50-heavy driving (especially in stop-start traffic) it could prove ideal. The IS 300h is indeed a lovely car — beautifully built and good to drive, but you might find that the cabin and boot are on the small side for your family needs. It could be worth looking at the larger GS 300h (same engine, similar real-world economy) or maybe the NX 300h crossover. If you fancy something a bit cheaper, the Prius is always a good choice, as is Kia’s really rather good Niro hybrid.

Read our reviews for more:

Lexus IS reviews

Lexus GS reviews

Lexus NX reviews

Toyota Prius reviews

Kia Niro reviews

Expert answer

Hi Anne Marie,

Stop-start systems on cars will stop working for a variety of reasons, some of them outside your control, but if you think your SEAT still has a problem after looking through this list of possibilities, best bet is to get the car along to your nearest SEAT dealer to check it out:

- Ambient temperature too cold
- Ambient temperature too hot (unlikely in Ireland!)
- Battery in poor condition
- Driver's seat belt usually must be on
- Driver's door and bonnet usually must be closed
- Engine temperature is too low
- Climate control settings may force the engine to stay on

Hope that's of some help. This question by an Audi owner has proven very popular and is mostly applicable to your car too.