Towbar electrics and stop-start..?
Discussion
Family member has just got a new (ie used) car fitted with a towbar and 7 pin electrics.
On the journey back from dealership she noticed that the stop start doesn't work. Can't remember if it did on test drive or not.
I popped round yesterday to have a look. No warning lights or anything but it's true, the stop start does not work. In the cars settings it just says 'system not available'. Car is otherwise in fine fettle, 9yrs old but FSH, one owner, fat sheaf of bills (inc one for fitting the towbar, it's a Witter if that makes any difference).
The last time I towed anything was about 25yrs ago so I have no idea about modern systems, but a quick google suggests towbar electrics can suspend stop start - is that true? Even when there is nothing being towed? And if so, how much of a big deal is it get the towbar and electrics removed and the stop-start working again?
She doesn't need the towbar, and even asked the dealer to remove it. But they 'forgot', which suggest they might know more about the associated hassle than she/we do;)
On the one hand it seems stop/start is not an MOT fail so it doesn't matter that much. But IME it makes quite a bit of difference to mpg in town driving so is worth her putting a bit of effort into getting it up and running again.
On the journey back from dealership she noticed that the stop start doesn't work. Can't remember if it did on test drive or not.
I popped round yesterday to have a look. No warning lights or anything but it's true, the stop start does not work. In the cars settings it just says 'system not available'. Car is otherwise in fine fettle, 9yrs old but FSH, one owner, fat sheaf of bills (inc one for fitting the towbar, it's a Witter if that makes any difference).
The last time I towed anything was about 25yrs ago so I have no idea about modern systems, but a quick google suggests towbar electrics can suspend stop start - is that true? Even when there is nothing being towed? And if so, how much of a big deal is it get the towbar and electrics removed and the stop-start working again?
She doesn't need the towbar, and even asked the dealer to remove it. But they 'forgot', which suggest they might know more about the associated hassle than she/we do;)
On the one hand it seems stop/start is not an MOT fail so it doesn't matter that much. But IME it makes quite a bit of difference to mpg in town driving so is worth her putting a bit of effort into getting it up and running again.
595Heaven said:
A lot of cars disable stop start whilst towing so as to keep engine ad transmission cooled.
There are other reasons that stop start system as well, so it might not be down to the towbar electrics. If you indicate, does the trailer tell tale lamp flash? If it does, I’d say there is something odd about the electrics as the car is acting like a trailer is connected to the electrics.
If not, I’d say it is not linked to the towbar.
What car is it?
Good q about the telltale, I didn't think to look for one. I will ask her. There are other reasons that stop start system as well, so it might not be down to the towbar electrics. If you indicate, does the trailer tell tale lamp flash? If it does, I’d say there is something odd about the electrics as the car is acting like a trailer is connected to the electrics.
If not, I’d say it is not linked to the towbar.
What car is it?
There are no signs of a failing battery or anything else that might interfere with the stop start. And no warning light either. That and the fact that it just says 'system not available' made me think it might have been disabled rather than have a fault specifically.
Car is a Mazda 3, petrol. It's exactly like one I used to have, we are becoming a Mazda family. Must be getting old;)
She says she wants to try and get it fixed as she does quite a lot of city driving where stop start does help the mpg.
I think it will.prob have to go back to the dealer she bought it from though, to go on the Mazda computer, which is a bit of a schlep so she may end up not bothering;)
I think it will.prob have to go back to the dealer she bought it from though, to go on the Mazda computer, which is a bit of a schlep so she may end up not bothering;)
Zarco said:
Is it possible its not working simply as the car has not been driven much recently?
S/S on my car doesn't work if the battery does not have enough charge. It didn't work for a while when I first bought it and I was doing lots of short journeys - presumably as the car had been sat at the dealership for a while. It will display the same 'not available' message.
Yes, my old one used to do the same if it had been sat for a while. But she did 50 miles at motorway speeds on the way home, before hitting the mean streets. I would have thought battery would have been boosted enough by then, but it's possible I guess. S/S on my car doesn't work if the battery does not have enough charge. It didn't work for a while when I first bought it and I was doing lots of short journeys - presumably as the car had been sat at the dealership for a while. It will display the same 'not available' message.
Update for anyone who hasn't been able to sleep for wondering how this turned out.
Spoke to sis today, stop start randomly started working half way home from a BH trip to the seaside.
So I guess maybe the battery was a bit flat. Towbar a red herring of my own makinf. Three weeks regular driving is quite a lot to wake it up though!
If it happens again that will be a clear signal for a new battery I reckon.
Spoke to sis today, stop start randomly started working half way home from a BH trip to the seaside.
So I guess maybe the battery was a bit flat. Towbar a red herring of my own makinf. Three weeks regular driving is quite a lot to wake it up though!
If it happens again that will be a clear signal for a new battery I reckon.
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